Status and results from OPERA

Tomoko ArigaLHEP University of Bern

on behalf of OPERA Swiss groups of Bern and ETHZ

OPERA

bull Aiming to prove the flavor-mixing neutrino oscillation hypothesis by appearance methodndash Appearance of new flavor nu-mu nu-taundash Search in the region predicted by other disappearance

experiments

bull Direct observation of nu-tau events in nuclear emulsion detectorsndash Sub-micron resolutionndash 125 kt of target mass

t (FL ~500mm)1ryvertex

non-munt CC interaction

CNGS beam

lt E gt 17 GeV

L 730 km

( e + e) 087

4

prompt negligible

Expected interactions in 5 years ~25400 CC + NC

~170 e + e CC~125 CC (m2 = 25 x 10-3 eV2)

L = 732 kmCERNLNGS

Tflight = 244 ms

CERN

LNGS

730 km

~10 tau decays are expectedto be observed

after 5 years running

102 cm

125 cm75 cm

neutrino

OPERA target

ECC brick

OPERA Brick = 57 nuclear emulsion films interleaved by 1 mm thick lead plates

OPERA Film = 2 emulsion layers (44 m thick)

poured on a 205 m plastic base

OPERA Film times 57 plates

Lead x 56 plates

OPERA Film

Lead plate

1mm03mm

The OPERA target consists of

about 150000 bricks

Total target mass 125 kton

OPERA detectorSM1 SM2

VETOTarget area Magnet and RPCs

PT Brick Manipulator System

Extract and validate the ECC brickDevelop and send to scanning labs

Parallel analysis of ECC bricksbull Validated bricks are sent to the scanning labs

ndash 10 scanning labs share the scanning

bull Swiss scanning station scanned the highest number of bricks in Europe for 2008 run

To Japan

Padova

To MosccowLHEP

GS

Scanning labs Nagoya (JP)LHEP Bern (CH)Napoli Bari Salerno Bologna Padova Roma Frascati (IT)Dubna (Ru)

Swiss scanning station in LHEP Bern

bull Largest scanning group in Europendash 10 physicists (Bern + ETHZ)ndash 5 microscopes with full-automatic plate changerndash Capability to scan more than 15 bricksweek

0

2E+18

4E+18

6E+18

8E+18

1E+19

12E+19

14E+19

16E+19

18E+19

18-J

un

28-J

un

8-Ju

l

18-J

ul

28-J

ul

7-A

ug

17-A

ug

27-A

ug

6-S

ep

16-S

ep

26-S

ep

6-O

ct

16-O

ct

26-O

ct

5-N

ov

inte

gra

ted

po

t

Total 1781019 pot

18kV cable repair

MD

PS magnet exchange septum bakeout

MD

SPS timing faultvacuum leak amp magnet exchange

CNGS maintenance

SPS extraction line Magnet ground fault MD

CNGS maintenance

Nominal 45 1019 potyr for 5 years

Beam to CNGSLHC FT MD

Beam to CNGSLHC FT

Beam to CNGS MD

2008 CNGS run (18 June - 03 Nov 2008) first physics run

Located neutrino interactions

Brick 81813

Brick 24487

Emulsion gives 3D vector data In ECC brick we can reconstruct vertices with an accuracy of a few micron(The frames correspond to emulsion films The other colored line shows the extrapolation of measured tracks The color indicates the Z-depth in the module)

1 cm

Brick 82372

(animation)

Status of event location in ECC for 2008 run

Scanning for 2008 run will be completed by September 2009

with muon without muon Total

Events in target 1663

Bricks developped 959 218 1177

Vertices located in ECC 678 119 797

Vertices in the dead material 17 4 21

Impact parameter distribution

mm

Analysis for located eventsbull Goal of 2008 run

ndash Check nu-tau detection efficiency by detecting charmed particles (similar life time and mass with tau)

bull Charm particles are produced in nu-mu CC interactionsbull ~23 events are expected for ~1200 nu-mu CC events

ndash Nu-tau detectionbull 07 event is expectedbull No clear candidate up to now

Particle Mass (MeVc2) Life time (10-15 s) cτ (micron)

τ 17769 291 871

D+ 18693 1040 3118

Ds+ 19682 500 1499

Λc+ 22865 200 599

Charm candidate 51284 (di-muon event)

kink

x-view

1ryvertex 4 mm

13 mm

flight length 1330 micronkink angle 209 mradIP of daughter 262 microndaughter muon 22 GeVcdecay Pt 046 GeVc

1ry muon

daughter muon

(animation)

Charm candidate 72853

Both 1ry vertex and decay point are in lead plate

muon

Lead plate

1ryvertex

IP wrt muon(micron)

IP wrt decay point(micron)

Momentum(GeVc)

Daughter1 370 05 13

Daughter2 135 04 23

342 micron

muon

(animation)

muon

muon

Lead plate (1 mm)

Hypothesis (1) D0 candidate

Hypothesis (2) t candidate

minimum kink angle 312 mradmuon momentum 17 GeVcPt gt 53 GeVc

Excluded by Pt Pt gt maximum decay Pt of t (09 GeVc)

1ryvertex

1ryvertex

D0

t

Charm candidates

Expected ratio Number of candidates

1-prong 37 5

2-prong 30 4

3-prong 19 1

4-prong 7 1

Analysis ongoing for located ~700 nu-mu CC eventsUp to now we have collected 11 candidates

13 events are expected for 700 nu-mu CC events(23 events are expected for 1200 nu-mu CC events)

Activities of Swiss group in OPERA analysis

bull Common for all labsndash Decay searchndash Kinematical analysis

bull Unique to Swiss groupndash Study of hadronic background for taundash Gamma detection energy estimation π0 reconstructionndash MC studies on tau and charmndash Electron ID energy estimationndash Low momentum muon IDndash Development of 3D display for event analysis

Study of hadronic background for tau

bull Motivationndash Hadronic re-interaction is a major source of background for hadronic decay

channel of tau Monte Carlo has large uncertainties (MC says a hadron track of 1mm length creates a decay-like topology with a probability of 10-5)

bull Methodndash Analyze the particles from neutrino interaction vertices Measure the number

of decay-like interactions and study Pt distribution etc

tau hadron1ryvertex

non-mu non-mu

Hadronic re-interaction background from nm NC interaction

nt CC interaction

Study of hadronic background for tau

bull Status 48 m was scanned and studied by Swiss group 2ry vertices were found for 12 events Analysis is in progress

bull Goal ~30 m track length to measure background for the total decay search length for NC events collected in 5 years

1ry 2ry1ry 2ry

Gamma detection and π0 reconstruction

E ~05 GeV

E ~81 GeV

2 e-showers give a reconstructed mass ~ 160 MeVc2

70 of 1-prong tau hadronic decays include p0Important to detect gamma from tau decay to improve SN

We are working on gamma detection from nu-mu interactions to prove the methodπ0 reconstruction is in progress

g e-pair

Status and prospect for the on-going 2009 run

bull 154x1019 pot have been already collected up to Aug 17thbull 45x1019 pot are requested ~2 tau events are expected to be

detected

2006 0076x1019 pot 0 int Commissioning

2007 0082x1019 pot 38 int Commissioning

2008 178x1019 pot 1663 int First physics run

2009 154x1019 pot up to now (Aug 17th)

1629 int 32x1019 pot are expected at end of the run

Summarybull The OPERA experiment is taking data in the CNGS beambull 178x1019 pot were collected during the first physics run in

2008bull The analysis of 2008 data is in progressbull The evaluation of total efficiencies is ongoingbull In 2009 run 154x1019pot were already collected

ndash 45x1019 pot are requestedndash 32x1019 pot are expected at the end of the runndash Detection of ~2 nu-tau events is expectedhellipSOON

BACKUP

OPERA signal and background

decay channel

BR () Signal m2 = 25 x 10-3 eV2

Background

177 29 017

e 178 35 017

h 495 31 024

3h 150 09 017

Total 104 075

Full mixing 5 years run 45x1019 pot year

Main background sources bull Production and decay of charmed particles bull Hadron re-interactionsbull Large angle muon scattering

Pt estimation for charm candidate 72853

Tau background by D0

bull Neutral charmed particle decay vertex mistaken as primary vertex in events where only a muon and D0

are produced at primary vertex

channel

Cut on the invariant mass to be used to reduce this background source

Pt cut

Daughter particle of τ

Daughter particle of hadronic re-interactions

Pt(GeVc) Pt(GeVc)

MC MC

• Status and results from OPERA
• OPERA
• CNGS beam
• Slide 4
• OPERA detector
• Parallel analysis of ECC bricks
• Swiss scanning station in LHEP Bern
• Slide 8
• Located neutrino interactions
• Status of event location in ECC for 2008 run
• Analysis for located events
• Slide 12
• Slide 13
• Slide 14
• Charm candidates
• Activities of Swiss group in OPERA analysis
• Study of hadronic background for tau
• Study of hadronic background for tau (2)
• Gamma detection and π0 reconstruction
• Status and prospect for the on-going 2009 run
• Summary
• Backup
• Slide 23
• Slide 24
• Slide 25
• Pt cut

OPERA

bull Aiming to prove the flavor-mixing neutrino oscillation hypothesis by appearance methodndash Appearance of new flavor nu-mu nu-taundash Search in the region predicted by other disappearance

experiments

bull Direct observation of nu-tau events in nuclear emulsion detectorsndash Sub-micron resolutionndash 125 kt of target mass

t (FL ~500mm)1ryvertex

non-munt CC interaction

CNGS beam

lt E gt 17 GeV

L 730 km

( e + e) 087

4

prompt negligible

Expected interactions in 5 years ~25400 CC + NC

~170 e + e CC~125 CC (m2 = 25 x 10-3 eV2)

L = 732 kmCERNLNGS

Tflight = 244 ms

CERN

LNGS

730 km

~10 tau decays are expectedto be observed

after 5 years running

102 cm

125 cm75 cm

neutrino

OPERA target

ECC brick

OPERA Brick = 57 nuclear emulsion films interleaved by 1 mm thick lead plates

OPERA Film = 2 emulsion layers (44 m thick)

poured on a 205 m plastic base

OPERA Film times 57 plates

Lead x 56 plates

OPERA Film

Lead plate

1mm03mm

The OPERA target consists of

about 150000 bricks

Total target mass 125 kton

OPERA detectorSM1 SM2

VETOTarget area Magnet and RPCs

PT Brick Manipulator System

Extract and validate the ECC brickDevelop and send to scanning labs

Parallel analysis of ECC bricksbull Validated bricks are sent to the scanning labs

ndash 10 scanning labs share the scanning

bull Swiss scanning station scanned the highest number of bricks in Europe for 2008 run

To Japan

Padova

To MosccowLHEP

GS

Scanning labs Nagoya (JP)LHEP Bern (CH)Napoli Bari Salerno Bologna Padova Roma Frascati (IT)Dubna (Ru)

Swiss scanning station in LHEP Bern

bull Largest scanning group in Europendash 10 physicists (Bern + ETHZ)ndash 5 microscopes with full-automatic plate changerndash Capability to scan more than 15 bricksweek

0

2E+18

4E+18

6E+18

8E+18

1E+19

12E+19

14E+19

16E+19

18E+19

18-J

un

28-J

un

8-Ju

l

18-J

ul

28-J

ul

7-A

ug

17-A

ug

27-A

ug

6-S

ep

16-S

ep

26-S

ep

6-O

ct

16-O

ct

26-O

ct

5-N

ov

inte

gra

ted

po

t

Total 1781019 pot

18kV cable repair

MD

PS magnet exchange septum bakeout

MD

SPS timing faultvacuum leak amp magnet exchange

CNGS maintenance

SPS extraction line Magnet ground fault MD

CNGS maintenance

Nominal 45 1019 potyr for 5 years

Beam to CNGSLHC FT MD

Beam to CNGSLHC FT

Beam to CNGS MD

2008 CNGS run (18 June - 03 Nov 2008) first physics run

Located neutrino interactions

Brick 81813

Brick 24487

Emulsion gives 3D vector data In ECC brick we can reconstruct vertices with an accuracy of a few micron(The frames correspond to emulsion films The other colored line shows the extrapolation of measured tracks The color indicates the Z-depth in the module)

1 cm

Brick 82372

(animation)

Status of event location in ECC for 2008 run

Scanning for 2008 run will be completed by September 2009

with muon without muon Total

Events in target 1663

Bricks developped 959 218 1177

Vertices located in ECC 678 119 797

Vertices in the dead material 17 4 21

Impact parameter distribution

mm

Analysis for located eventsbull Goal of 2008 run

ndash Check nu-tau detection efficiency by detecting charmed particles (similar life time and mass with tau)

bull Charm particles are produced in nu-mu CC interactionsbull ~23 events are expected for ~1200 nu-mu CC events

ndash Nu-tau detectionbull 07 event is expectedbull No clear candidate up to now

Particle Mass (MeVc2) Life time (10-15 s) cτ (micron)

τ 17769 291 871

D+ 18693 1040 3118

Ds+ 19682 500 1499

Λc+ 22865 200 599

Charm candidate 51284 (di-muon event)

kink

x-view

1ryvertex 4 mm

13 mm

flight length 1330 micronkink angle 209 mradIP of daughter 262 microndaughter muon 22 GeVcdecay Pt 046 GeVc

1ry muon

daughter muon

(animation)

Charm candidate 72853

Both 1ry vertex and decay point are in lead plate

muon

Lead plate

1ryvertex

IP wrt muon(micron)

IP wrt decay point(micron)

Momentum(GeVc)

Daughter1 370 05 13

Daughter2 135 04 23

342 micron

muon

(animation)

muon

muon

Lead plate (1 mm)

Hypothesis (1) D0 candidate

Hypothesis (2) t candidate

minimum kink angle 312 mradmuon momentum 17 GeVcPt gt 53 GeVc

Excluded by Pt Pt gt maximum decay Pt of t (09 GeVc)

1ryvertex

1ryvertex

D0

t

Charm candidates

Expected ratio Number of candidates

1-prong 37 5

2-prong 30 4

3-prong 19 1

4-prong 7 1

Analysis ongoing for located ~700 nu-mu CC eventsUp to now we have collected 11 candidates

13 events are expected for 700 nu-mu CC events(23 events are expected for 1200 nu-mu CC events)

Activities of Swiss group in OPERA analysis

bull Common for all labsndash Decay searchndash Kinematical analysis

bull Unique to Swiss groupndash Study of hadronic background for taundash Gamma detection energy estimation π0 reconstructionndash MC studies on tau and charmndash Electron ID energy estimationndash Low momentum muon IDndash Development of 3D display for event analysis

Study of hadronic background for tau

bull Motivationndash Hadronic re-interaction is a major source of background for hadronic decay

channel of tau Monte Carlo has large uncertainties (MC says a hadron track of 1mm length creates a decay-like topology with a probability of 10-5)

bull Methodndash Analyze the particles from neutrino interaction vertices Measure the number

of decay-like interactions and study Pt distribution etc

tau hadron1ryvertex

non-mu non-mu

Hadronic re-interaction background from nm NC interaction

nt CC interaction

Study of hadronic background for tau

bull Status 48 m was scanned and studied by Swiss group 2ry vertices were found for 12 events Analysis is in progress

bull Goal ~30 m track length to measure background for the total decay search length for NC events collected in 5 years

1ry 2ry1ry 2ry

Gamma detection and π0 reconstruction

E ~05 GeV

E ~81 GeV

2 e-showers give a reconstructed mass ~ 160 MeVc2

70 of 1-prong tau hadronic decays include p0Important to detect gamma from tau decay to improve SN

We are working on gamma detection from nu-mu interactions to prove the methodπ0 reconstruction is in progress

g e-pair

Status and prospect for the on-going 2009 run

bull 154x1019 pot have been already collected up to Aug 17thbull 45x1019 pot are requested ~2 tau events are expected to be

detected

2006 0076x1019 pot 0 int Commissioning

2007 0082x1019 pot 38 int Commissioning

2008 178x1019 pot 1663 int First physics run

2009 154x1019 pot up to now (Aug 17th)

1629 int 32x1019 pot are expected at end of the run

Summarybull The OPERA experiment is taking data in the CNGS beambull 178x1019 pot were collected during the first physics run in

2008bull The analysis of 2008 data is in progressbull The evaluation of total efficiencies is ongoingbull In 2009 run 154x1019pot were already collected

ndash 45x1019 pot are requestedndash 32x1019 pot are expected at the end of the runndash Detection of ~2 nu-tau events is expectedhellipSOON

BACKUP

OPERA signal and background

decay channel

BR () Signal m2 = 25 x 10-3 eV2

Background

177 29 017

e 178 35 017

h 495 31 024

3h 150 09 017

Total 104 075

Full mixing 5 years run 45x1019 pot year

Main background sources bull Production and decay of charmed particles bull Hadron re-interactionsbull Large angle muon scattering

Pt estimation for charm candidate 72853

Tau background by D0

bull Neutral charmed particle decay vertex mistaken as primary vertex in events where only a muon and D0

are produced at primary vertex

channel

Cut on the invariant mass to be used to reduce this background source

Pt cut

Daughter particle of τ

Daughter particle of hadronic re-interactions

Pt(GeVc) Pt(GeVc)

MC MC

• Status and results from OPERA
• OPERA
• CNGS beam
• Slide 4
• OPERA detector
• Parallel analysis of ECC bricks
• Swiss scanning station in LHEP Bern
• Slide 8
• Located neutrino interactions
• Status of event location in ECC for 2008 run
• Analysis for located events
• Slide 12
• Slide 13
• Slide 14
• Charm candidates
• Activities of Swiss group in OPERA analysis
• Study of hadronic background for tau
• Study of hadronic background for tau (2)
• Gamma detection and π0 reconstruction
• Status and prospect for the on-going 2009 run
• Summary
• Backup
• Slide 23
• Slide 24
• Slide 25
• Pt cut

CNGS beam

lt E gt 17 GeV

L 730 km

( e + e) 087

4

prompt negligible

Expected interactions in 5 years ~25400 CC + NC

~170 e + e CC~125 CC (m2 = 25 x 10-3 eV2)

L = 732 kmCERNLNGS

Tflight = 244 ms

CERN

LNGS

730 km

~10 tau decays are expectedto be observed

after 5 years running

102 cm

125 cm75 cm

neutrino

OPERA target

ECC brick

OPERA Brick = 57 nuclear emulsion films interleaved by 1 mm thick lead plates

OPERA Film = 2 emulsion layers (44 m thick)

poured on a 205 m plastic base

OPERA Film times 57 plates

Lead x 56 plates

OPERA Film

Lead plate

1mm03mm

The OPERA target consists of

about 150000 bricks

Total target mass 125 kton

OPERA detectorSM1 SM2

VETOTarget area Magnet and RPCs

PT Brick Manipulator System

Extract and validate the ECC brickDevelop and send to scanning labs

Parallel analysis of ECC bricksbull Validated bricks are sent to the scanning labs

ndash 10 scanning labs share the scanning

bull Swiss scanning station scanned the highest number of bricks in Europe for 2008 run

To Japan

Padova

To MosccowLHEP

GS

Scanning labs Nagoya (JP)LHEP Bern (CH)Napoli Bari Salerno Bologna Padova Roma Frascati (IT)Dubna (Ru)

Swiss scanning station in LHEP Bern

bull Largest scanning group in Europendash 10 physicists (Bern + ETHZ)ndash 5 microscopes with full-automatic plate changerndash Capability to scan more than 15 bricksweek

0

2E+18

4E+18

6E+18

8E+18

1E+19

12E+19

14E+19

16E+19

18E+19

18-J

un

28-J

un

8-Ju

l

18-J

ul

28-J

ul

7-A

ug

17-A

ug

27-A

ug

6-S

ep

16-S

ep

26-S

ep

6-O

ct

16-O

ct

26-O

ct

5-N

ov

inte

gra

ted

po

t

Total 1781019 pot

18kV cable repair

MD

PS magnet exchange septum bakeout

MD

SPS timing faultvacuum leak amp magnet exchange

CNGS maintenance

SPS extraction line Magnet ground fault MD

CNGS maintenance

Nominal 45 1019 potyr for 5 years

Beam to CNGSLHC FT MD

Beam to CNGSLHC FT

Beam to CNGS MD

2008 CNGS run (18 June - 03 Nov 2008) first physics run

Located neutrino interactions

Brick 81813

Brick 24487

Emulsion gives 3D vector data In ECC brick we can reconstruct vertices with an accuracy of a few micron(The frames correspond to emulsion films The other colored line shows the extrapolation of measured tracks The color indicates the Z-depth in the module)

1 cm

Brick 82372

(animation)

Status of event location in ECC for 2008 run

Scanning for 2008 run will be completed by September 2009

with muon without muon Total

Events in target 1663

Bricks developped 959 218 1177

Vertices located in ECC 678 119 797

Vertices in the dead material 17 4 21

Impact parameter distribution

mm

Analysis for located eventsbull Goal of 2008 run

ndash Check nu-tau detection efficiency by detecting charmed particles (similar life time and mass with tau)

bull Charm particles are produced in nu-mu CC interactionsbull ~23 events are expected for ~1200 nu-mu CC events

ndash Nu-tau detectionbull 07 event is expectedbull No clear candidate up to now

Particle Mass (MeVc2) Life time (10-15 s) cτ (micron)

τ 17769 291 871

D+ 18693 1040 3118

Ds+ 19682 500 1499

Λc+ 22865 200 599

Charm candidate 51284 (di-muon event)

kink

x-view

1ryvertex 4 mm

13 mm

flight length 1330 micronkink angle 209 mradIP of daughter 262 microndaughter muon 22 GeVcdecay Pt 046 GeVc

1ry muon

daughter muon

(animation)

Charm candidate 72853

Both 1ry vertex and decay point are in lead plate

muon

Lead plate

1ryvertex

IP wrt muon(micron)

IP wrt decay point(micron)

Momentum(GeVc)

Daughter1 370 05 13

Daughter2 135 04 23

342 micron

muon

(animation)

muon

muon

Lead plate (1 mm)

Hypothesis (1) D0 candidate

Hypothesis (2) t candidate

minimum kink angle 312 mradmuon momentum 17 GeVcPt gt 53 GeVc

Excluded by Pt Pt gt maximum decay Pt of t (09 GeVc)

1ryvertex

1ryvertex

D0

t

Charm candidates

Expected ratio Number of candidates

1-prong 37 5

2-prong 30 4

3-prong 19 1

4-prong 7 1

Analysis ongoing for located ~700 nu-mu CC eventsUp to now we have collected 11 candidates

13 events are expected for 700 nu-mu CC events(23 events are expected for 1200 nu-mu CC events)

Activities of Swiss group in OPERA analysis

bull Common for all labsndash Decay searchndash Kinematical analysis

bull Unique to Swiss groupndash Study of hadronic background for taundash Gamma detection energy estimation π0 reconstructionndash MC studies on tau and charmndash Electron ID energy estimationndash Low momentum muon IDndash Development of 3D display for event analysis

Study of hadronic background for tau

bull Motivationndash Hadronic re-interaction is a major source of background for hadronic decay

channel of tau Monte Carlo has large uncertainties (MC says a hadron track of 1mm length creates a decay-like topology with a probability of 10-5)

bull Methodndash Analyze the particles from neutrino interaction vertices Measure the number

of decay-like interactions and study Pt distribution etc

tau hadron1ryvertex

non-mu non-mu

Hadronic re-interaction background from nm NC interaction

nt CC interaction

Study of hadronic background for tau

bull Status 48 m was scanned and studied by Swiss group 2ry vertices were found for 12 events Analysis is in progress

bull Goal ~30 m track length to measure background for the total decay search length for NC events collected in 5 years

1ry 2ry1ry 2ry

Gamma detection and π0 reconstruction

E ~05 GeV

E ~81 GeV

2 e-showers give a reconstructed mass ~ 160 MeVc2

70 of 1-prong tau hadronic decays include p0Important to detect gamma from tau decay to improve SN

We are working on gamma detection from nu-mu interactions to prove the methodπ0 reconstruction is in progress

g e-pair

Status and prospect for the on-going 2009 run

bull 154x1019 pot have been already collected up to Aug 17thbull 45x1019 pot are requested ~2 tau events are expected to be

detected

2006 0076x1019 pot 0 int Commissioning

2007 0082x1019 pot 38 int Commissioning

2008 178x1019 pot 1663 int First physics run

2009 154x1019 pot up to now (Aug 17th)

1629 int 32x1019 pot are expected at end of the run

Summarybull The OPERA experiment is taking data in the CNGS beambull 178x1019 pot were collected during the first physics run in

2008bull The analysis of 2008 data is in progressbull The evaluation of total efficiencies is ongoingbull In 2009 run 154x1019pot were already collected

ndash 45x1019 pot are requestedndash 32x1019 pot are expected at the end of the runndash Detection of ~2 nu-tau events is expectedhellipSOON

BACKUP

OPERA signal and background

decay channel

BR () Signal m2 = 25 x 10-3 eV2

Background

177 29 017

e 178 35 017

h 495 31 024

3h 150 09 017

Total 104 075

Full mixing 5 years run 45x1019 pot year

Main background sources bull Production and decay of charmed particles bull Hadron re-interactionsbull Large angle muon scattering

Pt estimation for charm candidate 72853

Tau background by D0

bull Neutral charmed particle decay vertex mistaken as primary vertex in events where only a muon and D0

are produced at primary vertex

channel

Cut on the invariant mass to be used to reduce this background source

Pt cut

Daughter particle of τ

Daughter particle of hadronic re-interactions

Pt(GeVc) Pt(GeVc)

MC MC

• Status and results from OPERA
• OPERA
• CNGS beam
• Slide 4
• OPERA detector
• Parallel analysis of ECC bricks
• Swiss scanning station in LHEP Bern
• Slide 8
• Located neutrino interactions
• Status of event location in ECC for 2008 run
• Analysis for located events
• Slide 12
• Slide 13
• Slide 14
• Charm candidates
• Activities of Swiss group in OPERA analysis
• Study of hadronic background for tau
• Study of hadronic background for tau (2)
• Gamma detection and π0 reconstruction
• Status and prospect for the on-going 2009 run
• Summary
• Backup
• Slide 23
• Slide 24
• Slide 25
• Pt cut

102 cm

125 cm75 cm

neutrino

OPERA target

ECC brick

OPERA Brick = 57 nuclear emulsion films interleaved by 1 mm thick lead plates

OPERA Film = 2 emulsion layers (44 m thick)

poured on a 205 m plastic base

OPERA Film times 57 plates

Lead x 56 plates

OPERA Film

Lead plate

1mm03mm

The OPERA target consists of

about 150000 bricks

Total target mass 125 kton

OPERA detectorSM1 SM2

VETOTarget area Magnet and RPCs

PT Brick Manipulator System

Extract and validate the ECC brickDevelop and send to scanning labs

Parallel analysis of ECC bricksbull Validated bricks are sent to the scanning labs

ndash 10 scanning labs share the scanning

bull Swiss scanning station scanned the highest number of bricks in Europe for 2008 run

To Japan

Padova

To MosccowLHEP

GS

Scanning labs Nagoya (JP)LHEP Bern (CH)Napoli Bari Salerno Bologna Padova Roma Frascati (IT)Dubna (Ru)

Swiss scanning station in LHEP Bern

bull Largest scanning group in Europendash 10 physicists (Bern + ETHZ)ndash 5 microscopes with full-automatic plate changerndash Capability to scan more than 15 bricksweek

0

2E+18

4E+18

6E+18

8E+18

1E+19

12E+19

14E+19

16E+19

18E+19

18-J

un

28-J

un

8-Ju

l

18-J

ul

28-J

ul

7-A

ug

17-A

ug

27-A

ug

6-S

ep

16-S

ep

26-S

ep

6-O

ct

16-O

ct

26-O

ct

5-N

ov

inte

gra

ted

po

t

Total 1781019 pot

18kV cable repair

MD

PS magnet exchange septum bakeout

MD

SPS timing faultvacuum leak amp magnet exchange

CNGS maintenance

SPS extraction line Magnet ground fault MD

CNGS maintenance

Nominal 45 1019 potyr for 5 years

Beam to CNGSLHC FT MD

Beam to CNGSLHC FT

Beam to CNGS MD

2008 CNGS run (18 June - 03 Nov 2008) first physics run

Located neutrino interactions

Brick 81813

Brick 24487

Emulsion gives 3D vector data In ECC brick we can reconstruct vertices with an accuracy of a few micron(The frames correspond to emulsion films The other colored line shows the extrapolation of measured tracks The color indicates the Z-depth in the module)

1 cm

Brick 82372

(animation)

Status of event location in ECC for 2008 run

Scanning for 2008 run will be completed by September 2009

with muon without muon Total

Events in target 1663

Bricks developped 959 218 1177

Vertices located in ECC 678 119 797

Vertices in the dead material 17 4 21

Impact parameter distribution

mm

Analysis for located eventsbull Goal of 2008 run

ndash Check nu-tau detection efficiency by detecting charmed particles (similar life time and mass with tau)

bull Charm particles are produced in nu-mu CC interactionsbull ~23 events are expected for ~1200 nu-mu CC events

ndash Nu-tau detectionbull 07 event is expectedbull No clear candidate up to now

Particle Mass (MeVc2) Life time (10-15 s) cτ (micron)

τ 17769 291 871

D+ 18693 1040 3118

Ds+ 19682 500 1499

Λc+ 22865 200 599

Charm candidate 51284 (di-muon event)

kink

x-view

1ryvertex 4 mm

13 mm

flight length 1330 micronkink angle 209 mradIP of daughter 262 microndaughter muon 22 GeVcdecay Pt 046 GeVc

1ry muon

daughter muon

(animation)

Charm candidate 72853

Both 1ry vertex and decay point are in lead plate

muon

Lead plate

1ryvertex

IP wrt muon(micron)

IP wrt decay point(micron)

Momentum(GeVc)

Daughter1 370 05 13

Daughter2 135 04 23

342 micron

muon

(animation)

muon

muon

Lead plate (1 mm)

Hypothesis (1) D0 candidate

Hypothesis (2) t candidate

minimum kink angle 312 mradmuon momentum 17 GeVcPt gt 53 GeVc

Excluded by Pt Pt gt maximum decay Pt of t (09 GeVc)

1ryvertex

1ryvertex

D0

t

Charm candidates

Expected ratio Number of candidates

1-prong 37 5

2-prong 30 4

3-prong 19 1

4-prong 7 1

Analysis ongoing for located ~700 nu-mu CC eventsUp to now we have collected 11 candidates

13 events are expected for 700 nu-mu CC events(23 events are expected for 1200 nu-mu CC events)

Activities of Swiss group in OPERA analysis

bull Common for all labsndash Decay searchndash Kinematical analysis

bull Unique to Swiss groupndash Study of hadronic background for taundash Gamma detection energy estimation π0 reconstructionndash MC studies on tau and charmndash Electron ID energy estimationndash Low momentum muon IDndash Development of 3D display for event analysis

Study of hadronic background for tau

bull Motivationndash Hadronic re-interaction is a major source of background for hadronic decay

channel of tau Monte Carlo has large uncertainties (MC says a hadron track of 1mm length creates a decay-like topology with a probability of 10-5)

bull Methodndash Analyze the particles from neutrino interaction vertices Measure the number

of decay-like interactions and study Pt distribution etc

tau hadron1ryvertex

non-mu non-mu

Hadronic re-interaction background from nm NC interaction

nt CC interaction

Study of hadronic background for tau

bull Status 48 m was scanned and studied by Swiss group 2ry vertices were found for 12 events Analysis is in progress

bull Goal ~30 m track length to measure background for the total decay search length for NC events collected in 5 years

1ry 2ry1ry 2ry

Gamma detection and π0 reconstruction

E ~05 GeV

E ~81 GeV

2 e-showers give a reconstructed mass ~ 160 MeVc2

70 of 1-prong tau hadronic decays include p0Important to detect gamma from tau decay to improve SN

We are working on gamma detection from nu-mu interactions to prove the methodπ0 reconstruction is in progress

g e-pair

Status and prospect for the on-going 2009 run

bull 154x1019 pot have been already collected up to Aug 17thbull 45x1019 pot are requested ~2 tau events are expected to be

detected

2006 0076x1019 pot 0 int Commissioning

2007 0082x1019 pot 38 int Commissioning

2008 178x1019 pot 1663 int First physics run

2009 154x1019 pot up to now (Aug 17th)

1629 int 32x1019 pot are expected at end of the run

Summarybull The OPERA experiment is taking data in the CNGS beambull 178x1019 pot were collected during the first physics run in

2008bull The analysis of 2008 data is in progressbull The evaluation of total efficiencies is ongoingbull In 2009 run 154x1019pot were already collected

ndash 45x1019 pot are requestedndash 32x1019 pot are expected at the end of the runndash Detection of ~2 nu-tau events is expectedhellipSOON

BACKUP

OPERA signal and background

decay channel

BR () Signal m2 = 25 x 10-3 eV2

Background

177 29 017

e 178 35 017

h 495 31 024

3h 150 09 017

Total 104 075

Full mixing 5 years run 45x1019 pot year

Main background sources bull Production and decay of charmed particles bull Hadron re-interactionsbull Large angle muon scattering

Pt estimation for charm candidate 72853

Tau background by D0

bull Neutral charmed particle decay vertex mistaken as primary vertex in events where only a muon and D0

are produced at primary vertex

channel

Cut on the invariant mass to be used to reduce this background source

Pt cut

Daughter particle of τ

Daughter particle of hadronic re-interactions

Pt(GeVc) Pt(GeVc)

MC MC

• Status and results from OPERA
• OPERA
• CNGS beam
• Slide 4
• OPERA detector
• Parallel analysis of ECC bricks
• Swiss scanning station in LHEP Bern
• Slide 8
• Located neutrino interactions
• Status of event location in ECC for 2008 run
• Analysis for located events
• Slide 12
• Slide 13
• Slide 14
• Charm candidates
• Activities of Swiss group in OPERA analysis
• Study of hadronic background for tau
• Study of hadronic background for tau (2)
• Gamma detection and π0 reconstruction
• Status and prospect for the on-going 2009 run
• Summary
• Backup
• Slide 23
• Slide 24
• Slide 25
• Pt cut

OPERA detectorSM1 SM2

VETOTarget area Magnet and RPCs

PT Brick Manipulator System

Extract and validate the ECC brickDevelop and send to scanning labs

Parallel analysis of ECC bricksbull Validated bricks are sent to the scanning labs

ndash 10 scanning labs share the scanning

bull Swiss scanning station scanned the highest number of bricks in Europe for 2008 run

To Japan

Padova

To MosccowLHEP

GS

Scanning labs Nagoya (JP)LHEP Bern (CH)Napoli Bari Salerno Bologna Padova Roma Frascati (IT)Dubna (Ru)

Swiss scanning station in LHEP Bern

bull Largest scanning group in Europendash 10 physicists (Bern + ETHZ)ndash 5 microscopes with full-automatic plate changerndash Capability to scan more than 15 bricksweek

0

2E+18

4E+18

6E+18

8E+18

1E+19

12E+19

14E+19

16E+19

18E+19

18-J

un

28-J

un

8-Ju

l

18-J

ul

28-J

ul

7-A

ug

17-A

ug

27-A

ug

6-S

ep

16-S

ep

26-S

ep

6-O

ct

16-O

ct

26-O

ct

5-N

ov

inte

gra

ted

po

t

Total 1781019 pot

18kV cable repair

MD

PS magnet exchange septum bakeout

MD

SPS timing faultvacuum leak amp magnet exchange

CNGS maintenance

SPS extraction line Magnet ground fault MD

CNGS maintenance

Nominal 45 1019 potyr for 5 years

Beam to CNGSLHC FT MD

Beam to CNGSLHC FT

Beam to CNGS MD

2008 CNGS run (18 June - 03 Nov 2008) first physics run

Located neutrino interactions

Brick 81813

Brick 24487

Emulsion gives 3D vector data In ECC brick we can reconstruct vertices with an accuracy of a few micron(The frames correspond to emulsion films The other colored line shows the extrapolation of measured tracks The color indicates the Z-depth in the module)

1 cm

Brick 82372

(animation)

Status of event location in ECC for 2008 run

Scanning for 2008 run will be completed by September 2009

with muon without muon Total

Events in target 1663

Bricks developped 959 218 1177

Vertices located in ECC 678 119 797

Vertices in the dead material 17 4 21

Impact parameter distribution

mm

Analysis for located eventsbull Goal of 2008 run

ndash Check nu-tau detection efficiency by detecting charmed particles (similar life time and mass with tau)

bull Charm particles are produced in nu-mu CC interactionsbull ~23 events are expected for ~1200 nu-mu CC events

ndash Nu-tau detectionbull 07 event is expectedbull No clear candidate up to now

Particle Mass (MeVc2) Life time (10-15 s) cτ (micron)

τ 17769 291 871

D+ 18693 1040 3118

Ds+ 19682 500 1499

Λc+ 22865 200 599

Charm candidate 51284 (di-muon event)

kink

x-view

1ryvertex 4 mm

13 mm

flight length 1330 micronkink angle 209 mradIP of daughter 262 microndaughter muon 22 GeVcdecay Pt 046 GeVc

1ry muon

daughter muon

(animation)

Charm candidate 72853

Both 1ry vertex and decay point are in lead plate

muon

Lead plate

1ryvertex

IP wrt muon(micron)

IP wrt decay point(micron)

Momentum(GeVc)

Daughter1 370 05 13

Daughter2 135 04 23

342 micron

muon

(animation)

muon

muon

Lead plate (1 mm)

Hypothesis (1) D0 candidate

Hypothesis (2) t candidate

minimum kink angle 312 mradmuon momentum 17 GeVcPt gt 53 GeVc

Excluded by Pt Pt gt maximum decay Pt of t (09 GeVc)

1ryvertex

1ryvertex

D0

t

Charm candidates

Expected ratio Number of candidates

1-prong 37 5

2-prong 30 4

3-prong 19 1

4-prong 7 1

Analysis ongoing for located ~700 nu-mu CC eventsUp to now we have collected 11 candidates

13 events are expected for 700 nu-mu CC events(23 events are expected for 1200 nu-mu CC events)

Activities of Swiss group in OPERA analysis

bull Common for all labsndash Decay searchndash Kinematical analysis

bull Unique to Swiss groupndash Study of hadronic background for taundash Gamma detection energy estimation π0 reconstructionndash MC studies on tau and charmndash Electron ID energy estimationndash Low momentum muon IDndash Development of 3D display for event analysis

Study of hadronic background for tau

bull Motivationndash Hadronic re-interaction is a major source of background for hadronic decay

channel of tau Monte Carlo has large uncertainties (MC says a hadron track of 1mm length creates a decay-like topology with a probability of 10-5)

bull Methodndash Analyze the particles from neutrino interaction vertices Measure the number

of decay-like interactions and study Pt distribution etc

tau hadron1ryvertex

non-mu non-mu

Hadronic re-interaction background from nm NC interaction

nt CC interaction

Study of hadronic background for tau

bull Status 48 m was scanned and studied by Swiss group 2ry vertices were found for 12 events Analysis is in progress

bull Goal ~30 m track length to measure background for the total decay search length for NC events collected in 5 years

1ry 2ry1ry 2ry

Gamma detection and π0 reconstruction

E ~05 GeV

E ~81 GeV

2 e-showers give a reconstructed mass ~ 160 MeVc2

70 of 1-prong tau hadronic decays include p0Important to detect gamma from tau decay to improve SN

We are working on gamma detection from nu-mu interactions to prove the methodπ0 reconstruction is in progress

g e-pair

Status and prospect for the on-going 2009 run

bull 154x1019 pot have been already collected up to Aug 17thbull 45x1019 pot are requested ~2 tau events are expected to be

detected

2006 0076x1019 pot 0 int Commissioning

2007 0082x1019 pot 38 int Commissioning

2008 178x1019 pot 1663 int First physics run

2009 154x1019 pot up to now (Aug 17th)

1629 int 32x1019 pot are expected at end of the run

Summarybull The OPERA experiment is taking data in the CNGS beambull 178x1019 pot were collected during the first physics run in

2008bull The analysis of 2008 data is in progressbull The evaluation of total efficiencies is ongoingbull In 2009 run 154x1019pot were already collected

ndash 45x1019 pot are requestedndash 32x1019 pot are expected at the end of the runndash Detection of ~2 nu-tau events is expectedhellipSOON

BACKUP

OPERA signal and background

decay channel

BR () Signal m2 = 25 x 10-3 eV2

Background

177 29 017

e 178 35 017

h 495 31 024

3h 150 09 017

Total 104 075

Full mixing 5 years run 45x1019 pot year

Main background sources bull Production and decay of charmed particles bull Hadron re-interactionsbull Large angle muon scattering

Pt estimation for charm candidate 72853

Tau background by D0

bull Neutral charmed particle decay vertex mistaken as primary vertex in events where only a muon and D0

are produced at primary vertex

channel

Cut on the invariant mass to be used to reduce this background source

Pt cut

Daughter particle of τ

Daughter particle of hadronic re-interactions

Pt(GeVc) Pt(GeVc)

MC MC

• Status and results from OPERA
• OPERA
• CNGS beam
• Slide 4
• OPERA detector
• Parallel analysis of ECC bricks
• Swiss scanning station in LHEP Bern
• Slide 8
• Located neutrino interactions
• Status of event location in ECC for 2008 run
• Analysis for located events
• Slide 12
• Slide 13
• Slide 14
• Charm candidates
• Activities of Swiss group in OPERA analysis
• Study of hadronic background for tau
• Study of hadronic background for tau (2)
• Gamma detection and π0 reconstruction
• Status and prospect for the on-going 2009 run
• Summary
• Backup
• Slide 23
• Slide 24
• Slide 25
• Pt cut

Parallel analysis of ECC bricksbull Validated bricks are sent to the scanning labs

ndash 10 scanning labs share the scanning

bull Swiss scanning station scanned the highest number of bricks in Europe for 2008 run

To Japan

Padova

To MosccowLHEP

GS

Scanning labs Nagoya (JP)LHEP Bern (CH)Napoli Bari Salerno Bologna Padova Roma Frascati (IT)Dubna (Ru)

Swiss scanning station in LHEP Bern

bull Largest scanning group in Europendash 10 physicists (Bern + ETHZ)ndash 5 microscopes with full-automatic plate changerndash Capability to scan more than 15 bricksweek

0

2E+18

4E+18

6E+18

8E+18

1E+19

12E+19

14E+19

16E+19

18E+19

18-J

un

28-J

un

8-Ju

l

18-J

ul

28-J

ul

7-A

ug

17-A

ug

27-A

ug

6-S

ep

16-S

ep

26-S

ep

6-O

ct

16-O

ct

26-O

ct

5-N

ov

inte

gra

ted

po

t

Total 1781019 pot

18kV cable repair

MD

PS magnet exchange septum bakeout

MD

SPS timing faultvacuum leak amp magnet exchange

CNGS maintenance

SPS extraction line Magnet ground fault MD

CNGS maintenance

Nominal 45 1019 potyr for 5 years

Beam to CNGSLHC FT MD

Beam to CNGSLHC FT

Beam to CNGS MD

2008 CNGS run (18 June - 03 Nov 2008) first physics run

Located neutrino interactions

Brick 81813

Brick 24487

Emulsion gives 3D vector data In ECC brick we can reconstruct vertices with an accuracy of a few micron(The frames correspond to emulsion films The other colored line shows the extrapolation of measured tracks The color indicates the Z-depth in the module)

1 cm

Brick 82372

(animation)

Status of event location in ECC for 2008 run

Scanning for 2008 run will be completed by September 2009

with muon without muon Total

Events in target 1663

Bricks developped 959 218 1177

Vertices located in ECC 678 119 797

Vertices in the dead material 17 4 21

Impact parameter distribution

mm

Analysis for located eventsbull Goal of 2008 run

ndash Check nu-tau detection efficiency by detecting charmed particles (similar life time and mass with tau)

bull Charm particles are produced in nu-mu CC interactionsbull ~23 events are expected for ~1200 nu-mu CC events

ndash Nu-tau detectionbull 07 event is expectedbull No clear candidate up to now

Particle Mass (MeVc2) Life time (10-15 s) cτ (micron)

τ 17769 291 871

D+ 18693 1040 3118

Ds+ 19682 500 1499

Λc+ 22865 200 599

Charm candidate 51284 (di-muon event)

kink

x-view

1ryvertex 4 mm

13 mm

flight length 1330 micronkink angle 209 mradIP of daughter 262 microndaughter muon 22 GeVcdecay Pt 046 GeVc

1ry muon

daughter muon

(animation)

Charm candidate 72853

Both 1ry vertex and decay point are in lead plate

muon

Lead plate

1ryvertex

IP wrt muon(micron)

IP wrt decay point(micron)

Momentum(GeVc)

Daughter1 370 05 13

Daughter2 135 04 23

342 micron

muon

(animation)

muon

muon

Lead plate (1 mm)

Hypothesis (1) D0 candidate

Hypothesis (2) t candidate

minimum kink angle 312 mradmuon momentum 17 GeVcPt gt 53 GeVc

Excluded by Pt Pt gt maximum decay Pt of t (09 GeVc)

1ryvertex

1ryvertex

D0

t

Charm candidates

Expected ratio Number of candidates

1-prong 37 5

2-prong 30 4

3-prong 19 1

4-prong 7 1

Analysis ongoing for located ~700 nu-mu CC eventsUp to now we have collected 11 candidates

13 events are expected for 700 nu-mu CC events(23 events are expected for 1200 nu-mu CC events)

Activities of Swiss group in OPERA analysis

bull Common for all labsndash Decay searchndash Kinematical analysis

bull Unique to Swiss groupndash Study of hadronic background for taundash Gamma detection energy estimation π0 reconstructionndash MC studies on tau and charmndash Electron ID energy estimationndash Low momentum muon IDndash Development of 3D display for event analysis

Study of hadronic background for tau

bull Motivationndash Hadronic re-interaction is a major source of background for hadronic decay

channel of tau Monte Carlo has large uncertainties (MC says a hadron track of 1mm length creates a decay-like topology with a probability of 10-5)

bull Methodndash Analyze the particles from neutrino interaction vertices Measure the number

of decay-like interactions and study Pt distribution etc

tau hadron1ryvertex

non-mu non-mu

Hadronic re-interaction background from nm NC interaction

nt CC interaction

Study of hadronic background for tau

bull Status 48 m was scanned and studied by Swiss group 2ry vertices were found for 12 events Analysis is in progress

bull Goal ~30 m track length to measure background for the total decay search length for NC events collected in 5 years

1ry 2ry1ry 2ry

Gamma detection and π0 reconstruction

E ~05 GeV

E ~81 GeV

2 e-showers give a reconstructed mass ~ 160 MeVc2

70 of 1-prong tau hadronic decays include p0Important to detect gamma from tau decay to improve SN

We are working on gamma detection from nu-mu interactions to prove the methodπ0 reconstruction is in progress

g e-pair

Status and prospect for the on-going 2009 run

bull 154x1019 pot have been already collected up to Aug 17thbull 45x1019 pot are requested ~2 tau events are expected to be

detected

2006 0076x1019 pot 0 int Commissioning

2007 0082x1019 pot 38 int Commissioning

2008 178x1019 pot 1663 int First physics run

2009 154x1019 pot up to now (Aug 17th)

1629 int 32x1019 pot are expected at end of the run

Summarybull The OPERA experiment is taking data in the CNGS beambull 178x1019 pot were collected during the first physics run in

2008bull The analysis of 2008 data is in progressbull The evaluation of total efficiencies is ongoingbull In 2009 run 154x1019pot were already collected

ndash 45x1019 pot are requestedndash 32x1019 pot are expected at the end of the runndash Detection of ~2 nu-tau events is expectedhellipSOON

BACKUP

OPERA signal and background

decay channel

BR () Signal m2 = 25 x 10-3 eV2

Background

177 29 017

e 178 35 017

h 495 31 024

3h 150 09 017

Total 104 075

Full mixing 5 years run 45x1019 pot year

Main background sources bull Production and decay of charmed particles bull Hadron re-interactionsbull Large angle muon scattering

Pt estimation for charm candidate 72853

Tau background by D0

bull Neutral charmed particle decay vertex mistaken as primary vertex in events where only a muon and D0

are produced at primary vertex

channel

Cut on the invariant mass to be used to reduce this background source

Pt cut

Daughter particle of τ

Daughter particle of hadronic re-interactions

Pt(GeVc) Pt(GeVc)

MC MC

• Status and results from OPERA
• OPERA
• CNGS beam
• Slide 4
• OPERA detector
• Parallel analysis of ECC bricks
• Swiss scanning station in LHEP Bern
• Slide 8
• Located neutrino interactions
• Status of event location in ECC for 2008 run
• Analysis for located events
• Slide 12
• Slide 13
• Slide 14
• Charm candidates
• Activities of Swiss group in OPERA analysis
• Study of hadronic background for tau
• Study of hadronic background for tau (2)
• Gamma detection and π0 reconstruction
• Status and prospect for the on-going 2009 run
• Summary
• Backup
• Slide 23
• Slide 24
• Slide 25
• Pt cut

Swiss scanning station in LHEP Bern

bull Largest scanning group in Europendash 10 physicists (Bern + ETHZ)ndash 5 microscopes with full-automatic plate changerndash Capability to scan more than 15 bricksweek

0

2E+18

4E+18

6E+18

8E+18

1E+19

12E+19

14E+19

16E+19

18E+19

18-J

un

28-J

un

8-Ju

l

18-J

ul

28-J

ul

7-A

ug

17-A

ug

27-A

ug

6-S

ep

16-S

ep

26-S

ep

6-O

ct

16-O

ct

26-O

ct

5-N

ov

inte

gra

ted

po

t

Total 1781019 pot

18kV cable repair

MD

PS magnet exchange septum bakeout

MD

SPS timing faultvacuum leak amp magnet exchange

CNGS maintenance

SPS extraction line Magnet ground fault MD

CNGS maintenance

Nominal 45 1019 potyr for 5 years

Beam to CNGSLHC FT MD

Beam to CNGSLHC FT

Beam to CNGS MD

2008 CNGS run (18 June - 03 Nov 2008) first physics run

Located neutrino interactions

Brick 81813

Brick 24487

Emulsion gives 3D vector data In ECC brick we can reconstruct vertices with an accuracy of a few micron(The frames correspond to emulsion films The other colored line shows the extrapolation of measured tracks The color indicates the Z-depth in the module)

1 cm

Brick 82372

(animation)

Status of event location in ECC for 2008 run

Scanning for 2008 run will be completed by September 2009

with muon without muon Total

Events in target 1663

Bricks developped 959 218 1177

Vertices located in ECC 678 119 797

Vertices in the dead material 17 4 21

Impact parameter distribution

mm

Analysis for located eventsbull Goal of 2008 run

ndash Check nu-tau detection efficiency by detecting charmed particles (similar life time and mass with tau)

bull Charm particles are produced in nu-mu CC interactionsbull ~23 events are expected for ~1200 nu-mu CC events

ndash Nu-tau detectionbull 07 event is expectedbull No clear candidate up to now

Particle Mass (MeVc2) Life time (10-15 s) cτ (micron)

τ 17769 291 871

D+ 18693 1040 3118

Ds+ 19682 500 1499

Λc+ 22865 200 599

Charm candidate 51284 (di-muon event)

kink

x-view

1ryvertex 4 mm

13 mm

flight length 1330 micronkink angle 209 mradIP of daughter 262 microndaughter muon 22 GeVcdecay Pt 046 GeVc

1ry muon

daughter muon

(animation)

Charm candidate 72853

Both 1ry vertex and decay point are in lead plate

muon

Lead plate

1ryvertex

IP wrt muon(micron)

IP wrt decay point(micron)

Momentum(GeVc)

Daughter1 370 05 13

Daughter2 135 04 23

342 micron

muon

(animation)

muon

muon

Lead plate (1 mm)

Hypothesis (1) D0 candidate

Hypothesis (2) t candidate

minimum kink angle 312 mradmuon momentum 17 GeVcPt gt 53 GeVc

Excluded by Pt Pt gt maximum decay Pt of t (09 GeVc)

1ryvertex

1ryvertex

D0

t

Charm candidates

Expected ratio Number of candidates

1-prong 37 5

2-prong 30 4

3-prong 19 1

4-prong 7 1

Analysis ongoing for located ~700 nu-mu CC eventsUp to now we have collected 11 candidates

13 events are expected for 700 nu-mu CC events(23 events are expected for 1200 nu-mu CC events)

Activities of Swiss group in OPERA analysis

bull Common for all labsndash Decay searchndash Kinematical analysis

bull Unique to Swiss groupndash Study of hadronic background for taundash Gamma detection energy estimation π0 reconstructionndash MC studies on tau and charmndash Electron ID energy estimationndash Low momentum muon IDndash Development of 3D display for event analysis

Study of hadronic background for tau

bull Motivationndash Hadronic re-interaction is a major source of background for hadronic decay

channel of tau Monte Carlo has large uncertainties (MC says a hadron track of 1mm length creates a decay-like topology with a probability of 10-5)

bull Methodndash Analyze the particles from neutrino interaction vertices Measure the number

of decay-like interactions and study Pt distribution etc

tau hadron1ryvertex

non-mu non-mu

Hadronic re-interaction background from nm NC interaction

nt CC interaction

Study of hadronic background for tau

bull Status 48 m was scanned and studied by Swiss group 2ry vertices were found for 12 events Analysis is in progress

bull Goal ~30 m track length to measure background for the total decay search length for NC events collected in 5 years

1ry 2ry1ry 2ry

Gamma detection and π0 reconstruction

E ~05 GeV

E ~81 GeV

2 e-showers give a reconstructed mass ~ 160 MeVc2

70 of 1-prong tau hadronic decays include p0Important to detect gamma from tau decay to improve SN

We are working on gamma detection from nu-mu interactions to prove the methodπ0 reconstruction is in progress

g e-pair

Status and prospect for the on-going 2009 run

bull 154x1019 pot have been already collected up to Aug 17thbull 45x1019 pot are requested ~2 tau events are expected to be

detected

2006 0076x1019 pot 0 int Commissioning

2007 0082x1019 pot 38 int Commissioning

2008 178x1019 pot 1663 int First physics run

2009 154x1019 pot up to now (Aug 17th)

1629 int 32x1019 pot are expected at end of the run

Summarybull The OPERA experiment is taking data in the CNGS beambull 178x1019 pot were collected during the first physics run in

2008bull The analysis of 2008 data is in progressbull The evaluation of total efficiencies is ongoingbull In 2009 run 154x1019pot were already collected

ndash 45x1019 pot are requestedndash 32x1019 pot are expected at the end of the runndash Detection of ~2 nu-tau events is expectedhellipSOON

BACKUP

OPERA signal and background

decay channel

BR () Signal m2 = 25 x 10-3 eV2

Background

177 29 017

e 178 35 017

h 495 31 024

3h 150 09 017

Total 104 075

Full mixing 5 years run 45x1019 pot year

Main background sources bull Production and decay of charmed particles bull Hadron re-interactionsbull Large angle muon scattering

Pt estimation for charm candidate 72853

Tau background by D0

bull Neutral charmed particle decay vertex mistaken as primary vertex in events where only a muon and D0

are produced at primary vertex

channel

Cut on the invariant mass to be used to reduce this background source

Pt cut

Daughter particle of τ

Daughter particle of hadronic re-interactions

Pt(GeVc) Pt(GeVc)

MC MC

• Status and results from OPERA
• OPERA
• CNGS beam
• Slide 4
• OPERA detector
• Parallel analysis of ECC bricks
• Swiss scanning station in LHEP Bern
• Slide 8
• Located neutrino interactions
• Status of event location in ECC for 2008 run
• Analysis for located events
• Slide 12
• Slide 13
• Slide 14
• Charm candidates
• Activities of Swiss group in OPERA analysis
• Study of hadronic background for tau
• Study of hadronic background for tau (2)
• Gamma detection and π0 reconstruction
• Status and prospect for the on-going 2009 run
• Summary
• Backup
• Slide 23
• Slide 24
• Slide 25
• Pt cut

0

2E+18

4E+18

6E+18

8E+18

1E+19

12E+19

14E+19

16E+19

18E+19

18-J

un

28-J

un

8-Ju

l

18-J

ul

28-J

ul

7-A

ug

17-A

ug

27-A

ug

6-S

ep

16-S

ep

26-S

ep

6-O

ct

16-O

ct

26-O

ct

5-N

ov

inte

gra

ted

po

t

Total 1781019 pot

18kV cable repair

MD

PS magnet exchange septum bakeout

MD

SPS timing faultvacuum leak amp magnet exchange

CNGS maintenance

SPS extraction line Magnet ground fault MD

CNGS maintenance

Nominal 45 1019 potyr for 5 years

Beam to CNGSLHC FT MD

Beam to CNGSLHC FT

Beam to CNGS MD

2008 CNGS run (18 June - 03 Nov 2008) first physics run

Located neutrino interactions

Brick 81813

Brick 24487

Emulsion gives 3D vector data In ECC brick we can reconstruct vertices with an accuracy of a few micron(The frames correspond to emulsion films The other colored line shows the extrapolation of measured tracks The color indicates the Z-depth in the module)

1 cm

Brick 82372

(animation)

Status of event location in ECC for 2008 run

Scanning for 2008 run will be completed by September 2009

with muon without muon Total

Events in target 1663

Bricks developped 959 218 1177

Vertices located in ECC 678 119 797

Vertices in the dead material 17 4 21

Impact parameter distribution

mm

Analysis for located eventsbull Goal of 2008 run

ndash Check nu-tau detection efficiency by detecting charmed particles (similar life time and mass with tau)

bull Charm particles are produced in nu-mu CC interactionsbull ~23 events are expected for ~1200 nu-mu CC events

ndash Nu-tau detectionbull 07 event is expectedbull No clear candidate up to now

Particle Mass (MeVc2) Life time (10-15 s) cτ (micron)

τ 17769 291 871

D+ 18693 1040 3118

Ds+ 19682 500 1499

Λc+ 22865 200 599

Charm candidate 51284 (di-muon event)

kink

x-view

1ryvertex 4 mm

13 mm

flight length 1330 micronkink angle 209 mradIP of daughter 262 microndaughter muon 22 GeVcdecay Pt 046 GeVc

1ry muon

daughter muon

(animation)

Charm candidate 72853

Both 1ry vertex and decay point are in lead plate

muon

Lead plate

1ryvertex

IP wrt muon(micron)

IP wrt decay point(micron)

Momentum(GeVc)

Daughter1 370 05 13

Daughter2 135 04 23

342 micron

muon

(animation)

muon

muon

Lead plate (1 mm)

Hypothesis (1) D0 candidate

Hypothesis (2) t candidate

minimum kink angle 312 mradmuon momentum 17 GeVcPt gt 53 GeVc

Excluded by Pt Pt gt maximum decay Pt of t (09 GeVc)

1ryvertex

1ryvertex

D0

t

Charm candidates

Expected ratio Number of candidates

1-prong 37 5

2-prong 30 4

3-prong 19 1

4-prong 7 1

Analysis ongoing for located ~700 nu-mu CC eventsUp to now we have collected 11 candidates

13 events are expected for 700 nu-mu CC events(23 events are expected for 1200 nu-mu CC events)

Activities of Swiss group in OPERA analysis

bull Common for all labsndash Decay searchndash Kinematical analysis

bull Unique to Swiss groupndash Study of hadronic background for taundash Gamma detection energy estimation π0 reconstructionndash MC studies on tau and charmndash Electron ID energy estimationndash Low momentum muon IDndash Development of 3D display for event analysis

Study of hadronic background for tau

bull Motivationndash Hadronic re-interaction is a major source of background for hadronic decay

channel of tau Monte Carlo has large uncertainties (MC says a hadron track of 1mm length creates a decay-like topology with a probability of 10-5)

bull Methodndash Analyze the particles from neutrino interaction vertices Measure the number

of decay-like interactions and study Pt distribution etc

tau hadron1ryvertex

non-mu non-mu

Hadronic re-interaction background from nm NC interaction

nt CC interaction

Study of hadronic background for tau

bull Status 48 m was scanned and studied by Swiss group 2ry vertices were found for 12 events Analysis is in progress

bull Goal ~30 m track length to measure background for the total decay search length for NC events collected in 5 years

1ry 2ry1ry 2ry

Gamma detection and π0 reconstruction

E ~05 GeV

E ~81 GeV

2 e-showers give a reconstructed mass ~ 160 MeVc2

70 of 1-prong tau hadronic decays include p0Important to detect gamma from tau decay to improve SN

We are working on gamma detection from nu-mu interactions to prove the methodπ0 reconstruction is in progress

g e-pair

Status and prospect for the on-going 2009 run

bull 154x1019 pot have been already collected up to Aug 17thbull 45x1019 pot are requested ~2 tau events are expected to be

detected

2006 0076x1019 pot 0 int Commissioning

2007 0082x1019 pot 38 int Commissioning

2008 178x1019 pot 1663 int First physics run

2009 154x1019 pot up to now (Aug 17th)

1629 int 32x1019 pot are expected at end of the run

Summarybull The OPERA experiment is taking data in the CNGS beambull 178x1019 pot were collected during the first physics run in

2008bull The analysis of 2008 data is in progressbull The evaluation of total efficiencies is ongoingbull In 2009 run 154x1019pot were already collected

ndash 45x1019 pot are requestedndash 32x1019 pot are expected at the end of the runndash Detection of ~2 nu-tau events is expectedhellipSOON

BACKUP

OPERA signal and background

decay channel

BR () Signal m2 = 25 x 10-3 eV2

Background

177 29 017

e 178 35 017

h 495 31 024

3h 150 09 017

Total 104 075

Full mixing 5 years run 45x1019 pot year

Main background sources bull Production and decay of charmed particles bull Hadron re-interactionsbull Large angle muon scattering

Pt estimation for charm candidate 72853

Tau background by D0

bull Neutral charmed particle decay vertex mistaken as primary vertex in events where only a muon and D0

are produced at primary vertex

channel

Cut on the invariant mass to be used to reduce this background source

Pt cut

Daughter particle of τ

Daughter particle of hadronic re-interactions

Pt(GeVc) Pt(GeVc)

MC MC

• Status and results from OPERA
• OPERA
• CNGS beam
• Slide 4
• OPERA detector
• Parallel analysis of ECC bricks
• Swiss scanning station in LHEP Bern
• Slide 8
• Located neutrino interactions
• Status of event location in ECC for 2008 run
• Analysis for located events
• Slide 12
• Slide 13
• Slide 14
• Charm candidates
• Activities of Swiss group in OPERA analysis
• Study of hadronic background for tau
• Study of hadronic background for tau (2)
• Gamma detection and π0 reconstruction
• Status and prospect for the on-going 2009 run
• Summary
• Backup
• Slide 23
• Slide 24
• Slide 25
• Pt cut

Located neutrino interactions

Brick 81813

Brick 24487

Emulsion gives 3D vector data In ECC brick we can reconstruct vertices with an accuracy of a few micron(The frames correspond to emulsion films The other colored line shows the extrapolation of measured tracks The color indicates the Z-depth in the module)

1 cm

Brick 82372

(animation)

Status of event location in ECC for 2008 run

Scanning for 2008 run will be completed by September 2009

with muon without muon Total

Events in target 1663

Bricks developped 959 218 1177

Vertices located in ECC 678 119 797

Vertices in the dead material 17 4 21

Impact parameter distribution

mm

Analysis for located eventsbull Goal of 2008 run

ndash Check nu-tau detection efficiency by detecting charmed particles (similar life time and mass with tau)

bull Charm particles are produced in nu-mu CC interactionsbull ~23 events are expected for ~1200 nu-mu CC events

ndash Nu-tau detectionbull 07 event is expectedbull No clear candidate up to now

Particle Mass (MeVc2) Life time (10-15 s) cτ (micron)

τ 17769 291 871

D+ 18693 1040 3118

Ds+ 19682 500 1499

Λc+ 22865 200 599

Charm candidate 51284 (di-muon event)

kink

x-view

1ryvertex 4 mm

13 mm

flight length 1330 micronkink angle 209 mradIP of daughter 262 microndaughter muon 22 GeVcdecay Pt 046 GeVc

1ry muon

daughter muon

(animation)

Charm candidate 72853

Both 1ry vertex and decay point are in lead plate

muon

Lead plate

1ryvertex

IP wrt muon(micron)

IP wrt decay point(micron)

Momentum(GeVc)

Daughter1 370 05 13

Daughter2 135 04 23

342 micron

muon

(animation)

muon

muon

Lead plate (1 mm)

Hypothesis (1) D0 candidate

Hypothesis (2) t candidate

minimum kink angle 312 mradmuon momentum 17 GeVcPt gt 53 GeVc

Excluded by Pt Pt gt maximum decay Pt of t (09 GeVc)

1ryvertex

1ryvertex

D0

t

Charm candidates

Expected ratio Number of candidates

1-prong 37 5

2-prong 30 4

3-prong 19 1

4-prong 7 1

Analysis ongoing for located ~700 nu-mu CC eventsUp to now we have collected 11 candidates

13 events are expected for 700 nu-mu CC events(23 events are expected for 1200 nu-mu CC events)

Activities of Swiss group in OPERA analysis

bull Common for all labsndash Decay searchndash Kinematical analysis

bull Unique to Swiss groupndash Study of hadronic background for taundash Gamma detection energy estimation π0 reconstructionndash MC studies on tau and charmndash Electron ID energy estimationndash Low momentum muon IDndash Development of 3D display for event analysis

Study of hadronic background for tau

bull Motivationndash Hadronic re-interaction is a major source of background for hadronic decay

channel of tau Monte Carlo has large uncertainties (MC says a hadron track of 1mm length creates a decay-like topology with a probability of 10-5)

bull Methodndash Analyze the particles from neutrino interaction vertices Measure the number

of decay-like interactions and study Pt distribution etc

tau hadron1ryvertex

non-mu non-mu

Hadronic re-interaction background from nm NC interaction

nt CC interaction

Study of hadronic background for tau

bull Status 48 m was scanned and studied by Swiss group 2ry vertices were found for 12 events Analysis is in progress

bull Goal ~30 m track length to measure background for the total decay search length for NC events collected in 5 years

1ry 2ry1ry 2ry

Gamma detection and π0 reconstruction

E ~05 GeV

E ~81 GeV

2 e-showers give a reconstructed mass ~ 160 MeVc2

70 of 1-prong tau hadronic decays include p0Important to detect gamma from tau decay to improve SN

We are working on gamma detection from nu-mu interactions to prove the methodπ0 reconstruction is in progress

g e-pair

Status and prospect for the on-going 2009 run

bull 154x1019 pot have been already collected up to Aug 17thbull 45x1019 pot are requested ~2 tau events are expected to be

detected

2006 0076x1019 pot 0 int Commissioning

2007 0082x1019 pot 38 int Commissioning

2008 178x1019 pot 1663 int First physics run

2009 154x1019 pot up to now (Aug 17th)

1629 int 32x1019 pot are expected at end of the run

Summarybull The OPERA experiment is taking data in the CNGS beambull 178x1019 pot were collected during the first physics run in

2008bull The analysis of 2008 data is in progressbull The evaluation of total efficiencies is ongoingbull In 2009 run 154x1019pot were already collected

ndash 45x1019 pot are requestedndash 32x1019 pot are expected at the end of the runndash Detection of ~2 nu-tau events is expectedhellipSOON

BACKUP

OPERA signal and background

decay channel

BR () Signal m2 = 25 x 10-3 eV2

Background

177 29 017

e 178 35 017

h 495 31 024

3h 150 09 017

Total 104 075

Full mixing 5 years run 45x1019 pot year

Main background sources bull Production and decay of charmed particles bull Hadron re-interactionsbull Large angle muon scattering

Pt estimation for charm candidate 72853

Tau background by D0

bull Neutral charmed particle decay vertex mistaken as primary vertex in events where only a muon and D0

are produced at primary vertex

channel

Cut on the invariant mass to be used to reduce this background source

Pt cut

Daughter particle of τ

Daughter particle of hadronic re-interactions

Pt(GeVc) Pt(GeVc)

MC MC

• Status and results from OPERA
• OPERA
• CNGS beam
• Slide 4
• OPERA detector
• Parallel analysis of ECC bricks
• Swiss scanning station in LHEP Bern
• Slide 8
• Located neutrino interactions
• Status of event location in ECC for 2008 run
• Analysis for located events
• Slide 12
• Slide 13
• Slide 14
• Charm candidates
• Activities of Swiss group in OPERA analysis
• Study of hadronic background for tau
• Study of hadronic background for tau (2)
• Gamma detection and π0 reconstruction
• Status and prospect for the on-going 2009 run
• Summary
• Backup
• Slide 23
• Slide 24
• Slide 25
• Pt cut

Status of event location in ECC for 2008 run

Scanning for 2008 run will be completed by September 2009

with muon without muon Total

Events in target 1663

Bricks developped 959 218 1177

Vertices located in ECC 678 119 797

Vertices in the dead material 17 4 21

Impact parameter distribution

mm

Analysis for located eventsbull Goal of 2008 run

ndash Check nu-tau detection efficiency by detecting charmed particles (similar life time and mass with tau)

bull Charm particles are produced in nu-mu CC interactionsbull ~23 events are expected for ~1200 nu-mu CC events

ndash Nu-tau detectionbull 07 event is expectedbull No clear candidate up to now

Particle Mass (MeVc2) Life time (10-15 s) cτ (micron)

τ 17769 291 871

D+ 18693 1040 3118

Ds+ 19682 500 1499

Λc+ 22865 200 599

Charm candidate 51284 (di-muon event)

kink

x-view

1ryvertex 4 mm

13 mm

flight length 1330 micronkink angle 209 mradIP of daughter 262 microndaughter muon 22 GeVcdecay Pt 046 GeVc

1ry muon

daughter muon

(animation)

Charm candidate 72853

Both 1ry vertex and decay point are in lead plate

muon

Lead plate

1ryvertex

IP wrt muon(micron)

IP wrt decay point(micron)

Momentum(GeVc)

Daughter1 370 05 13

Daughter2 135 04 23

342 micron

muon

(animation)

muon

muon

Lead plate (1 mm)

Hypothesis (1) D0 candidate

Hypothesis (2) t candidate

minimum kink angle 312 mradmuon momentum 17 GeVcPt gt 53 GeVc

Excluded by Pt Pt gt maximum decay Pt of t (09 GeVc)

1ryvertex

1ryvertex

D0

t

Charm candidates

Expected ratio Number of candidates

1-prong 37 5

2-prong 30 4

3-prong 19 1

4-prong 7 1

Analysis ongoing for located ~700 nu-mu CC eventsUp to now we have collected 11 candidates

13 events are expected for 700 nu-mu CC events(23 events are expected for 1200 nu-mu CC events)

Activities of Swiss group in OPERA analysis

bull Common for all labsndash Decay searchndash Kinematical analysis

bull Unique to Swiss groupndash Study of hadronic background for taundash Gamma detection energy estimation π0 reconstructionndash MC studies on tau and charmndash Electron ID energy estimationndash Low momentum muon IDndash Development of 3D display for event analysis

Study of hadronic background for tau

bull Motivationndash Hadronic re-interaction is a major source of background for hadronic decay

channel of tau Monte Carlo has large uncertainties (MC says a hadron track of 1mm length creates a decay-like topology with a probability of 10-5)

bull Methodndash Analyze the particles from neutrino interaction vertices Measure the number

of decay-like interactions and study Pt distribution etc

tau hadron1ryvertex

non-mu non-mu

Hadronic re-interaction background from nm NC interaction

nt CC interaction

Study of hadronic background for tau

bull Status 48 m was scanned and studied by Swiss group 2ry vertices were found for 12 events Analysis is in progress

bull Goal ~30 m track length to measure background for the total decay search length for NC events collected in 5 years

1ry 2ry1ry 2ry

Gamma detection and π0 reconstruction

E ~05 GeV

E ~81 GeV

2 e-showers give a reconstructed mass ~ 160 MeVc2

70 of 1-prong tau hadronic decays include p0Important to detect gamma from tau decay to improve SN

We are working on gamma detection from nu-mu interactions to prove the methodπ0 reconstruction is in progress

g e-pair

Status and prospect for the on-going 2009 run

bull 154x1019 pot have been already collected up to Aug 17thbull 45x1019 pot are requested ~2 tau events are expected to be

detected

2006 0076x1019 pot 0 int Commissioning

2007 0082x1019 pot 38 int Commissioning

2008 178x1019 pot 1663 int First physics run

2009 154x1019 pot up to now (Aug 17th)

1629 int 32x1019 pot are expected at end of the run

Summarybull The OPERA experiment is taking data in the CNGS beambull 178x1019 pot were collected during the first physics run in

2008bull The analysis of 2008 data is in progressbull The evaluation of total efficiencies is ongoingbull In 2009 run 154x1019pot were already collected

ndash 45x1019 pot are requestedndash 32x1019 pot are expected at the end of the runndash Detection of ~2 nu-tau events is expectedhellipSOON

BACKUP

OPERA signal and background

decay channel

BR () Signal m2 = 25 x 10-3 eV2

Background

177 29 017

e 178 35 017

h 495 31 024

3h 150 09 017

Total 104 075

Full mixing 5 years run 45x1019 pot year

Main background sources bull Production and decay of charmed particles bull Hadron re-interactionsbull Large angle muon scattering

Pt estimation for charm candidate 72853

Tau background by D0

bull Neutral charmed particle decay vertex mistaken as primary vertex in events where only a muon and D0

are produced at primary vertex

channel

Cut on the invariant mass to be used to reduce this background source

Pt cut

Daughter particle of τ

Daughter particle of hadronic re-interactions

Pt(GeVc) Pt(GeVc)

MC MC

• Status and results from OPERA
• OPERA
• CNGS beam
• Slide 4
• OPERA detector
• Parallel analysis of ECC bricks
• Swiss scanning station in LHEP Bern
• Slide 8
• Located neutrino interactions
• Status of event location in ECC for 2008 run
• Analysis for located events
• Slide 12
• Slide 13
• Slide 14
• Charm candidates
• Activities of Swiss group in OPERA analysis
• Study of hadronic background for tau
• Study of hadronic background for tau (2)
• Gamma detection and π0 reconstruction
• Status and prospect for the on-going 2009 run
• Summary
• Backup
• Slide 23
• Slide 24
• Slide 25
• Pt cut

Analysis for located eventsbull Goal of 2008 run

ndash Check nu-tau detection efficiency by detecting charmed particles (similar life time and mass with tau)

bull Charm particles are produced in nu-mu CC interactionsbull ~23 events are expected for ~1200 nu-mu CC events

ndash Nu-tau detectionbull 07 event is expectedbull No clear candidate up to now

Particle Mass (MeVc2) Life time (10-15 s) cτ (micron)

τ 17769 291 871

D+ 18693 1040 3118

Ds+ 19682 500 1499

Λc+ 22865 200 599

Charm candidate 51284 (di-muon event)

kink

x-view

1ryvertex 4 mm

13 mm

flight length 1330 micronkink angle 209 mradIP of daughter 262 microndaughter muon 22 GeVcdecay Pt 046 GeVc

1ry muon

daughter muon

(animation)

Charm candidate 72853

Both 1ry vertex and decay point are in lead plate

muon

Lead plate

1ryvertex

IP wrt muon(micron)

IP wrt decay point(micron)

Momentum(GeVc)

Daughter1 370 05 13

Daughter2 135 04 23

342 micron

muon

(animation)

muon

muon

Lead plate (1 mm)

Hypothesis (1) D0 candidate

Hypothesis (2) t candidate

minimum kink angle 312 mradmuon momentum 17 GeVcPt gt 53 GeVc

Excluded by Pt Pt gt maximum decay Pt of t (09 GeVc)

1ryvertex

1ryvertex

D0

t

Charm candidates

Expected ratio Number of candidates

1-prong 37 5

2-prong 30 4

3-prong 19 1

4-prong 7 1

Analysis ongoing for located ~700 nu-mu CC eventsUp to now we have collected 11 candidates

13 events are expected for 700 nu-mu CC events(23 events are expected for 1200 nu-mu CC events)

Activities of Swiss group in OPERA analysis

bull Common for all labsndash Decay searchndash Kinematical analysis

bull Unique to Swiss groupndash Study of hadronic background for taundash Gamma detection energy estimation π0 reconstructionndash MC studies on tau and charmndash Electron ID energy estimationndash Low momentum muon IDndash Development of 3D display for event analysis

Study of hadronic background for tau

bull Motivationndash Hadronic re-interaction is a major source of background for hadronic decay

channel of tau Monte Carlo has large uncertainties (MC says a hadron track of 1mm length creates a decay-like topology with a probability of 10-5)

bull Methodndash Analyze the particles from neutrino interaction vertices Measure the number

of decay-like interactions and study Pt distribution etc

tau hadron1ryvertex

non-mu non-mu

Hadronic re-interaction background from nm NC interaction

nt CC interaction

Study of hadronic background for tau

bull Status 48 m was scanned and studied by Swiss group 2ry vertices were found for 12 events Analysis is in progress

bull Goal ~30 m track length to measure background for the total decay search length for NC events collected in 5 years

1ry 2ry1ry 2ry

Gamma detection and π0 reconstruction

E ~05 GeV

E ~81 GeV

2 e-showers give a reconstructed mass ~ 160 MeVc2

70 of 1-prong tau hadronic decays include p0Important to detect gamma from tau decay to improve SN

We are working on gamma detection from nu-mu interactions to prove the methodπ0 reconstruction is in progress

g e-pair

Status and prospect for the on-going 2009 run

bull 154x1019 pot have been already collected up to Aug 17thbull 45x1019 pot are requested ~2 tau events are expected to be

detected

2006 0076x1019 pot 0 int Commissioning

2007 0082x1019 pot 38 int Commissioning

2008 178x1019 pot 1663 int First physics run

2009 154x1019 pot up to now (Aug 17th)

1629 int 32x1019 pot are expected at end of the run

Summarybull The OPERA experiment is taking data in the CNGS beambull 178x1019 pot were collected during the first physics run in

2008bull The analysis of 2008 data is in progressbull The evaluation of total efficiencies is ongoingbull In 2009 run 154x1019pot were already collected

ndash 45x1019 pot are requestedndash 32x1019 pot are expected at the end of the runndash Detection of ~2 nu-tau events is expectedhellipSOON

BACKUP

OPERA signal and background

decay channel

BR () Signal m2 = 25 x 10-3 eV2

Background

177 29 017

e 178 35 017

h 495 31 024

3h 150 09 017

Total 104 075

Full mixing 5 years run 45x1019 pot year

Main background sources bull Production and decay of charmed particles bull Hadron re-interactionsbull Large angle muon scattering

Pt estimation for charm candidate 72853

Tau background by D0

bull Neutral charmed particle decay vertex mistaken as primary vertex in events where only a muon and D0

are produced at primary vertex

channel

Cut on the invariant mass to be used to reduce this background source

Pt cut

Daughter particle of τ

Daughter particle of hadronic re-interactions

Pt(GeVc) Pt(GeVc)

MC MC

• Status and results from OPERA
• OPERA
• CNGS beam
• Slide 4
• OPERA detector
• Parallel analysis of ECC bricks
• Swiss scanning station in LHEP Bern
• Slide 8
• Located neutrino interactions
• Status of event location in ECC for 2008 run
• Analysis for located events
• Slide 12
• Slide 13
• Slide 14
• Charm candidates
• Activities of Swiss group in OPERA analysis
• Study of hadronic background for tau
• Study of hadronic background for tau (2)
• Gamma detection and π0 reconstruction
• Status and prospect for the on-going 2009 run
• Summary
• Backup
• Slide 23
• Slide 24
• Slide 25
• Pt cut

Charm candidate 51284 (di-muon event)

kink

x-view

1ryvertex 4 mm

13 mm

flight length 1330 micronkink angle 209 mradIP of daughter 262 microndaughter muon 22 GeVcdecay Pt 046 GeVc

1ry muon

daughter muon

(animation)

Charm candidate 72853

Both 1ry vertex and decay point are in lead plate

muon

Lead plate

1ryvertex

IP wrt muon(micron)

IP wrt decay point(micron)

Momentum(GeVc)

Daughter1 370 05 13

Daughter2 135 04 23

342 micron

muon

(animation)

muon

muon

Lead plate (1 mm)

Hypothesis (1) D0 candidate

Hypothesis (2) t candidate

minimum kink angle 312 mradmuon momentum 17 GeVcPt gt 53 GeVc

Excluded by Pt Pt gt maximum decay Pt of t (09 GeVc)

1ryvertex

1ryvertex

D0

t

Charm candidates

Expected ratio Number of candidates

1-prong 37 5

2-prong 30 4

3-prong 19 1

4-prong 7 1

Analysis ongoing for located ~700 nu-mu CC eventsUp to now we have collected 11 candidates

13 events are expected for 700 nu-mu CC events(23 events are expected for 1200 nu-mu CC events)

Activities of Swiss group in OPERA analysis

bull Common for all labsndash Decay searchndash Kinematical analysis

bull Unique to Swiss groupndash Study of hadronic background for taundash Gamma detection energy estimation π0 reconstructionndash MC studies on tau and charmndash Electron ID energy estimationndash Low momentum muon IDndash Development of 3D display for event analysis

Study of hadronic background for tau

bull Motivationndash Hadronic re-interaction is a major source of background for hadronic decay

channel of tau Monte Carlo has large uncertainties (MC says a hadron track of 1mm length creates a decay-like topology with a probability of 10-5)

bull Methodndash Analyze the particles from neutrino interaction vertices Measure the number

of decay-like interactions and study Pt distribution etc

tau hadron1ryvertex

non-mu non-mu

Hadronic re-interaction background from nm NC interaction

nt CC interaction

Study of hadronic background for tau

bull Status 48 m was scanned and studied by Swiss group 2ry vertices were found for 12 events Analysis is in progress

bull Goal ~30 m track length to measure background for the total decay search length for NC events collected in 5 years

1ry 2ry1ry 2ry

Gamma detection and π0 reconstruction

E ~05 GeV

E ~81 GeV

2 e-showers give a reconstructed mass ~ 160 MeVc2

70 of 1-prong tau hadronic decays include p0Important to detect gamma from tau decay to improve SN

We are working on gamma detection from nu-mu interactions to prove the methodπ0 reconstruction is in progress

g e-pair

Status and prospect for the on-going 2009 run

bull 154x1019 pot have been already collected up to Aug 17thbull 45x1019 pot are requested ~2 tau events are expected to be

detected

2006 0076x1019 pot 0 int Commissioning

2007 0082x1019 pot 38 int Commissioning

2008 178x1019 pot 1663 int First physics run

2009 154x1019 pot up to now (Aug 17th)

1629 int 32x1019 pot are expected at end of the run

Summarybull The OPERA experiment is taking data in the CNGS beambull 178x1019 pot were collected during the first physics run in

2008bull The analysis of 2008 data is in progressbull The evaluation of total efficiencies is ongoingbull In 2009 run 154x1019pot were already collected

ndash 45x1019 pot are requestedndash 32x1019 pot are expected at the end of the runndash Detection of ~2 nu-tau events is expectedhellipSOON

BACKUP

OPERA signal and background

decay channel

BR () Signal m2 = 25 x 10-3 eV2

Background

177 29 017

e 178 35 017

h 495 31 024

3h 150 09 017

Total 104 075

Full mixing 5 years run 45x1019 pot year

Main background sources bull Production and decay of charmed particles bull Hadron re-interactionsbull Large angle muon scattering

Pt estimation for charm candidate 72853

Tau background by D0

bull Neutral charmed particle decay vertex mistaken as primary vertex in events where only a muon and D0

are produced at primary vertex

channel

Cut on the invariant mass to be used to reduce this background source

Pt cut

Daughter particle of τ

Daughter particle of hadronic re-interactions

Pt(GeVc) Pt(GeVc)

MC MC

• Status and results from OPERA
• OPERA
• CNGS beam
• Slide 4
• OPERA detector
• Parallel analysis of ECC bricks
• Swiss scanning station in LHEP Bern
• Slide 8
• Located neutrino interactions
• Status of event location in ECC for 2008 run
• Analysis for located events
• Slide 12
• Slide 13
• Slide 14
• Charm candidates
• Activities of Swiss group in OPERA analysis
• Study of hadronic background for tau
• Study of hadronic background for tau (2)
• Gamma detection and π0 reconstruction
• Status and prospect for the on-going 2009 run
• Summary
• Backup
• Slide 23
• Slide 24
• Slide 25
• Pt cut

Charm candidate 72853

Both 1ry vertex and decay point are in lead plate

muon

Lead plate

1ryvertex

IP wrt muon(micron)

IP wrt decay point(micron)

Momentum(GeVc)

Daughter1 370 05 13

Daughter2 135 04 23

342 micron

muon

(animation)

muon

muon

Lead plate (1 mm)

Hypothesis (1) D0 candidate

Hypothesis (2) t candidate

minimum kink angle 312 mradmuon momentum 17 GeVcPt gt 53 GeVc

Excluded by Pt Pt gt maximum decay Pt of t (09 GeVc)

1ryvertex

1ryvertex

D0

t

Charm candidates

Expected ratio Number of candidates

1-prong 37 5

2-prong 30 4

3-prong 19 1

4-prong 7 1

Analysis ongoing for located ~700 nu-mu CC eventsUp to now we have collected 11 candidates

13 events are expected for 700 nu-mu CC events(23 events are expected for 1200 nu-mu CC events)

Activities of Swiss group in OPERA analysis

bull Common for all labsndash Decay searchndash Kinematical analysis

bull Unique to Swiss groupndash Study of hadronic background for taundash Gamma detection energy estimation π0 reconstructionndash MC studies on tau and charmndash Electron ID energy estimationndash Low momentum muon IDndash Development of 3D display for event analysis

Study of hadronic background for tau

bull Motivationndash Hadronic re-interaction is a major source of background for hadronic decay

channel of tau Monte Carlo has large uncertainties (MC says a hadron track of 1mm length creates a decay-like topology with a probability of 10-5)

bull Methodndash Analyze the particles from neutrino interaction vertices Measure the number

of decay-like interactions and study Pt distribution etc

tau hadron1ryvertex

non-mu non-mu

Hadronic re-interaction background from nm NC interaction

nt CC interaction

Study of hadronic background for tau

bull Status 48 m was scanned and studied by Swiss group 2ry vertices were found for 12 events Analysis is in progress

bull Goal ~30 m track length to measure background for the total decay search length for NC events collected in 5 years

1ry 2ry1ry 2ry

Gamma detection and π0 reconstruction

E ~05 GeV

E ~81 GeV

2 e-showers give a reconstructed mass ~ 160 MeVc2

70 of 1-prong tau hadronic decays include p0Important to detect gamma from tau decay to improve SN

We are working on gamma detection from nu-mu interactions to prove the methodπ0 reconstruction is in progress

g e-pair

Status and prospect for the on-going 2009 run

bull 154x1019 pot have been already collected up to Aug 17thbull 45x1019 pot are requested ~2 tau events are expected to be

detected

2006 0076x1019 pot 0 int Commissioning

2007 0082x1019 pot 38 int Commissioning

2008 178x1019 pot 1663 int First physics run

2009 154x1019 pot up to now (Aug 17th)

1629 int 32x1019 pot are expected at end of the run

Summarybull The OPERA experiment is taking data in the CNGS beambull 178x1019 pot were collected during the first physics run in

2008bull The analysis of 2008 data is in progressbull The evaluation of total efficiencies is ongoingbull In 2009 run 154x1019pot were already collected

ndash 45x1019 pot are requestedndash 32x1019 pot are expected at the end of the runndash Detection of ~2 nu-tau events is expectedhellipSOON

BACKUP

OPERA signal and background

decay channel

BR () Signal m2 = 25 x 10-3 eV2

Background

177 29 017

e 178 35 017

h 495 31 024

3h 150 09 017

Total 104 075

Full mixing 5 years run 45x1019 pot year

Main background sources bull Production and decay of charmed particles bull Hadron re-interactionsbull Large angle muon scattering

Pt estimation for charm candidate 72853

Tau background by D0

bull Neutral charmed particle decay vertex mistaken as primary vertex in events where only a muon and D0

are produced at primary vertex

channel

Cut on the invariant mass to be used to reduce this background source

Pt cut

Daughter particle of τ

Daughter particle of hadronic re-interactions

Pt(GeVc) Pt(GeVc)

MC MC

• Status and results from OPERA
• OPERA
• CNGS beam
• Slide 4
• OPERA detector
• Parallel analysis of ECC bricks
• Swiss scanning station in LHEP Bern
• Slide 8
• Located neutrino interactions
• Status of event location in ECC for 2008 run
• Analysis for located events
• Slide 12
• Slide 13
• Slide 14
• Charm candidates
• Activities of Swiss group in OPERA analysis
• Study of hadronic background for tau
• Study of hadronic background for tau (2)
• Gamma detection and π0 reconstruction
• Status and prospect for the on-going 2009 run
• Summary
• Backup
• Slide 23
• Slide 24
• Slide 25
• Pt cut

muon

muon

Lead plate (1 mm)

Hypothesis (1) D0 candidate

Hypothesis (2) t candidate

minimum kink angle 312 mradmuon momentum 17 GeVcPt gt 53 GeVc

Excluded by Pt Pt gt maximum decay Pt of t (09 GeVc)

1ryvertex

1ryvertex

D0

t

Charm candidates

Expected ratio Number of candidates

1-prong 37 5

2-prong 30 4

3-prong 19 1

4-prong 7 1

Analysis ongoing for located ~700 nu-mu CC eventsUp to now we have collected 11 candidates

13 events are expected for 700 nu-mu CC events(23 events are expected for 1200 nu-mu CC events)

Activities of Swiss group in OPERA analysis

bull Common for all labsndash Decay searchndash Kinematical analysis

bull Unique to Swiss groupndash Study of hadronic background for taundash Gamma detection energy estimation π0 reconstructionndash MC studies on tau and charmndash Electron ID energy estimationndash Low momentum muon IDndash Development of 3D display for event analysis

Study of hadronic background for tau

bull Motivationndash Hadronic re-interaction is a major source of background for hadronic decay

channel of tau Monte Carlo has large uncertainties (MC says a hadron track of 1mm length creates a decay-like topology with a probability of 10-5)

bull Methodndash Analyze the particles from neutrino interaction vertices Measure the number

of decay-like interactions and study Pt distribution etc

tau hadron1ryvertex

non-mu non-mu

Hadronic re-interaction background from nm NC interaction

nt CC interaction

Study of hadronic background for tau

bull Status 48 m was scanned and studied by Swiss group 2ry vertices were found for 12 events Analysis is in progress

bull Goal ~30 m track length to measure background for the total decay search length for NC events collected in 5 years

1ry 2ry1ry 2ry

Gamma detection and π0 reconstruction

E ~05 GeV

E ~81 GeV

2 e-showers give a reconstructed mass ~ 160 MeVc2

70 of 1-prong tau hadronic decays include p0Important to detect gamma from tau decay to improve SN

We are working on gamma detection from nu-mu interactions to prove the methodπ0 reconstruction is in progress

g e-pair

Status and prospect for the on-going 2009 run

bull 154x1019 pot have been already collected up to Aug 17thbull 45x1019 pot are requested ~2 tau events are expected to be

detected

2006 0076x1019 pot 0 int Commissioning

2007 0082x1019 pot 38 int Commissioning

2008 178x1019 pot 1663 int First physics run

2009 154x1019 pot up to now (Aug 17th)

1629 int 32x1019 pot are expected at end of the run

Summarybull The OPERA experiment is taking data in the CNGS beambull 178x1019 pot were collected during the first physics run in

2008bull The analysis of 2008 data is in progressbull The evaluation of total efficiencies is ongoingbull In 2009 run 154x1019pot were already collected

ndash 45x1019 pot are requestedndash 32x1019 pot are expected at the end of the runndash Detection of ~2 nu-tau events is expectedhellipSOON

BACKUP

OPERA signal and background

decay channel

BR () Signal m2 = 25 x 10-3 eV2

Background

177 29 017

e 178 35 017

h 495 31 024

3h 150 09 017

Total 104 075

Full mixing 5 years run 45x1019 pot year

Main background sources bull Production and decay of charmed particles bull Hadron re-interactionsbull Large angle muon scattering

Pt estimation for charm candidate 72853

Tau background by D0

bull Neutral charmed particle decay vertex mistaken as primary vertex in events where only a muon and D0

are produced at primary vertex

channel

Cut on the invariant mass to be used to reduce this background source

Pt cut

Daughter particle of τ

Daughter particle of hadronic re-interactions

Pt(GeVc) Pt(GeVc)

MC MC

• Status and results from OPERA
• OPERA
• CNGS beam
• Slide 4
• OPERA detector
• Parallel analysis of ECC bricks
• Swiss scanning station in LHEP Bern
• Slide 8
• Located neutrino interactions
• Status of event location in ECC for 2008 run
• Analysis for located events
• Slide 12
• Slide 13
• Slide 14
• Charm candidates
• Activities of Swiss group in OPERA analysis
• Study of hadronic background for tau
• Study of hadronic background for tau (2)
• Gamma detection and π0 reconstruction
• Status and prospect for the on-going 2009 run
• Summary
• Backup
• Slide 23
• Slide 24
• Slide 25
• Pt cut

Charm candidates

Expected ratio Number of candidates

1-prong 37 5

2-prong 30 4

3-prong 19 1

4-prong 7 1

Analysis ongoing for located ~700 nu-mu CC eventsUp to now we have collected 11 candidates

13 events are expected for 700 nu-mu CC events(23 events are expected for 1200 nu-mu CC events)

Activities of Swiss group in OPERA analysis

bull Common for all labsndash Decay searchndash Kinematical analysis

bull Unique to Swiss groupndash Study of hadronic background for taundash Gamma detection energy estimation π0 reconstructionndash MC studies on tau and charmndash Electron ID energy estimationndash Low momentum muon IDndash Development of 3D display for event analysis

Study of hadronic background for tau

bull Motivationndash Hadronic re-interaction is a major source of background for hadronic decay

channel of tau Monte Carlo has large uncertainties (MC says a hadron track of 1mm length creates a decay-like topology with a probability of 10-5)

bull Methodndash Analyze the particles from neutrino interaction vertices Measure the number

of decay-like interactions and study Pt distribution etc

tau hadron1ryvertex

non-mu non-mu

Hadronic re-interaction background from nm NC interaction

nt CC interaction

Study of hadronic background for tau

bull Status 48 m was scanned and studied by Swiss group 2ry vertices were found for 12 events Analysis is in progress

bull Goal ~30 m track length to measure background for the total decay search length for NC events collected in 5 years

1ry 2ry1ry 2ry

Gamma detection and π0 reconstruction

E ~05 GeV

E ~81 GeV

2 e-showers give a reconstructed mass ~ 160 MeVc2

70 of 1-prong tau hadronic decays include p0Important to detect gamma from tau decay to improve SN

We are working on gamma detection from nu-mu interactions to prove the methodπ0 reconstruction is in progress

g e-pair

Status and prospect for the on-going 2009 run

bull 154x1019 pot have been already collected up to Aug 17thbull 45x1019 pot are requested ~2 tau events are expected to be

detected

2006 0076x1019 pot 0 int Commissioning

2007 0082x1019 pot 38 int Commissioning

2008 178x1019 pot 1663 int First physics run

2009 154x1019 pot up to now (Aug 17th)

1629 int 32x1019 pot are expected at end of the run

Summarybull The OPERA experiment is taking data in the CNGS beambull 178x1019 pot were collected during the first physics run in

2008bull The analysis of 2008 data is in progressbull The evaluation of total efficiencies is ongoingbull In 2009 run 154x1019pot were already collected

ndash 45x1019 pot are requestedndash 32x1019 pot are expected at the end of the runndash Detection of ~2 nu-tau events is expectedhellipSOON

BACKUP

OPERA signal and background

decay channel

BR () Signal m2 = 25 x 10-3 eV2

Background

177 29 017

e 178 35 017

h 495 31 024

3h 150 09 017

Total 104 075

Full mixing 5 years run 45x1019 pot year

Main background sources bull Production and decay of charmed particles bull Hadron re-interactionsbull Large angle muon scattering

Pt estimation for charm candidate 72853

Tau background by D0

bull Neutral charmed particle decay vertex mistaken as primary vertex in events where only a muon and D0

are produced at primary vertex

channel

Cut on the invariant mass to be used to reduce this background source

Pt cut

Daughter particle of τ

Daughter particle of hadronic re-interactions

Pt(GeVc) Pt(GeVc)

MC MC

• Status and results from OPERA
• OPERA
• CNGS beam
• Slide 4
• OPERA detector
• Parallel analysis of ECC bricks
• Swiss scanning station in LHEP Bern
• Slide 8
• Located neutrino interactions
• Status of event location in ECC for 2008 run
• Analysis for located events
• Slide 12
• Slide 13
• Slide 14
• Charm candidates
• Activities of Swiss group in OPERA analysis
• Study of hadronic background for tau
• Study of hadronic background for tau (2)
• Gamma detection and π0 reconstruction
• Status and prospect for the on-going 2009 run
• Summary
• Backup
• Slide 23
• Slide 24
• Slide 25
• Pt cut

Activities of Swiss group in OPERA analysis

bull Common for all labsndash Decay searchndash Kinematical analysis

bull Unique to Swiss groupndash Study of hadronic background for taundash Gamma detection energy estimation π0 reconstructionndash MC studies on tau and charmndash Electron ID energy estimationndash Low momentum muon IDndash Development of 3D display for event analysis

Study of hadronic background for tau

bull Motivationndash Hadronic re-interaction is a major source of background for hadronic decay

channel of tau Monte Carlo has large uncertainties (MC says a hadron track of 1mm length creates a decay-like topology with a probability of 10-5)

bull Methodndash Analyze the particles from neutrino interaction vertices Measure the number

of decay-like interactions and study Pt distribution etc

tau hadron1ryvertex

non-mu non-mu

Hadronic re-interaction background from nm NC interaction

nt CC interaction

Study of hadronic background for tau

bull Status 48 m was scanned and studied by Swiss group 2ry vertices were found for 12 events Analysis is in progress

bull Goal ~30 m track length to measure background for the total decay search length for NC events collected in 5 years

1ry 2ry1ry 2ry

Gamma detection and π0 reconstruction

E ~05 GeV

E ~81 GeV

2 e-showers give a reconstructed mass ~ 160 MeVc2

70 of 1-prong tau hadronic decays include p0Important to detect gamma from tau decay to improve SN

We are working on gamma detection from nu-mu interactions to prove the methodπ0 reconstruction is in progress

g e-pair

Status and prospect for the on-going 2009 run

bull 154x1019 pot have been already collected up to Aug 17thbull 45x1019 pot are requested ~2 tau events are expected to be

detected

2006 0076x1019 pot 0 int Commissioning

2007 0082x1019 pot 38 int Commissioning

2008 178x1019 pot 1663 int First physics run

2009 154x1019 pot up to now (Aug 17th)

1629 int 32x1019 pot are expected at end of the run

Summarybull The OPERA experiment is taking data in the CNGS beambull 178x1019 pot were collected during the first physics run in

2008bull The analysis of 2008 data is in progressbull The evaluation of total efficiencies is ongoingbull In 2009 run 154x1019pot were already collected

ndash 45x1019 pot are requestedndash 32x1019 pot are expected at the end of the runndash Detection of ~2 nu-tau events is expectedhellipSOON

BACKUP

OPERA signal and background

decay channel

BR () Signal m2 = 25 x 10-3 eV2

Background

177 29 017

e 178 35 017

h 495 31 024

3h 150 09 017

Total 104 075

Full mixing 5 years run 45x1019 pot year

Main background sources bull Production and decay of charmed particles bull Hadron re-interactionsbull Large angle muon scattering

Pt estimation for charm candidate 72853

Tau background by D0

bull Neutral charmed particle decay vertex mistaken as primary vertex in events where only a muon and D0

are produced at primary vertex

channel

Cut on the invariant mass to be used to reduce this background source

Pt cut

Daughter particle of τ

Daughter particle of hadronic re-interactions

Pt(GeVc) Pt(GeVc)

MC MC

• Status and results from OPERA
• OPERA
• CNGS beam
• Slide 4
• OPERA detector
• Parallel analysis of ECC bricks
• Swiss scanning station in LHEP Bern
• Slide 8
• Located neutrino interactions
• Status of event location in ECC for 2008 run
• Analysis for located events
• Slide 12
• Slide 13
• Slide 14
• Charm candidates
• Activities of Swiss group in OPERA analysis
• Study of hadronic background for tau
• Study of hadronic background for tau (2)
• Gamma detection and π0 reconstruction
• Status and prospect for the on-going 2009 run
• Summary
• Backup
• Slide 23
• Slide 24
• Slide 25
• Pt cut

Study of hadronic background for tau

bull Motivationndash Hadronic re-interaction is a major source of background for hadronic decay

channel of tau Monte Carlo has large uncertainties (MC says a hadron track of 1mm length creates a decay-like topology with a probability of 10-5)

bull Methodndash Analyze the particles from neutrino interaction vertices Measure the number

of decay-like interactions and study Pt distribution etc

tau hadron1ryvertex

non-mu non-mu

Hadronic re-interaction background from nm NC interaction

nt CC interaction

Study of hadronic background for tau

bull Status 48 m was scanned and studied by Swiss group 2ry vertices were found for 12 events Analysis is in progress

bull Goal ~30 m track length to measure background for the total decay search length for NC events collected in 5 years

1ry 2ry1ry 2ry

Gamma detection and π0 reconstruction

E ~05 GeV

E ~81 GeV

2 e-showers give a reconstructed mass ~ 160 MeVc2

70 of 1-prong tau hadronic decays include p0Important to detect gamma from tau decay to improve SN

We are working on gamma detection from nu-mu interactions to prove the methodπ0 reconstruction is in progress

g e-pair

Status and prospect for the on-going 2009 run

bull 154x1019 pot have been already collected up to Aug 17thbull 45x1019 pot are requested ~2 tau events are expected to be

detected

2006 0076x1019 pot 0 int Commissioning

2007 0082x1019 pot 38 int Commissioning

2008 178x1019 pot 1663 int First physics run

2009 154x1019 pot up to now (Aug 17th)

1629 int 32x1019 pot are expected at end of the run

Summarybull The OPERA experiment is taking data in the CNGS beambull 178x1019 pot were collected during the first physics run in

2008bull The analysis of 2008 data is in progressbull The evaluation of total efficiencies is ongoingbull In 2009 run 154x1019pot were already collected

ndash 45x1019 pot are requestedndash 32x1019 pot are expected at the end of the runndash Detection of ~2 nu-tau events is expectedhellipSOON

BACKUP

OPERA signal and background

decay channel

BR () Signal m2 = 25 x 10-3 eV2

Background

177 29 017

e 178 35 017

h 495 31 024

3h 150 09 017

Total 104 075

Full mixing 5 years run 45x1019 pot year

Main background sources bull Production and decay of charmed particles bull Hadron re-interactionsbull Large angle muon scattering

Pt estimation for charm candidate 72853

Tau background by D0

bull Neutral charmed particle decay vertex mistaken as primary vertex in events where only a muon and D0

are produced at primary vertex

channel

Cut on the invariant mass to be used to reduce this background source

Pt cut

Daughter particle of τ

Daughter particle of hadronic re-interactions

Pt(GeVc) Pt(GeVc)

MC MC

• Status and results from OPERA
• OPERA
• CNGS beam
• Slide 4
• OPERA detector
• Parallel analysis of ECC bricks
• Swiss scanning station in LHEP Bern
• Slide 8
• Located neutrino interactions
• Status of event location in ECC for 2008 run
• Analysis for located events
• Slide 12
• Slide 13
• Slide 14
• Charm candidates
• Activities of Swiss group in OPERA analysis
• Study of hadronic background for tau
• Study of hadronic background for tau (2)
• Gamma detection and π0 reconstruction
• Status and prospect for the on-going 2009 run
• Summary
• Backup
• Slide 23
• Slide 24
• Slide 25
• Pt cut

Study of hadronic background for tau

bull Status 48 m was scanned and studied by Swiss group 2ry vertices were found for 12 events Analysis is in progress

bull Goal ~30 m track length to measure background for the total decay search length for NC events collected in 5 years

1ry 2ry1ry 2ry

Gamma detection and π0 reconstruction

E ~05 GeV

E ~81 GeV

2 e-showers give a reconstructed mass ~ 160 MeVc2

70 of 1-prong tau hadronic decays include p0Important to detect gamma from tau decay to improve SN

We are working on gamma detection from nu-mu interactions to prove the methodπ0 reconstruction is in progress

g e-pair

Status and prospect for the on-going 2009 run

bull 154x1019 pot have been already collected up to Aug 17thbull 45x1019 pot are requested ~2 tau events are expected to be

detected

2006 0076x1019 pot 0 int Commissioning

2007 0082x1019 pot 38 int Commissioning

2008 178x1019 pot 1663 int First physics run

2009 154x1019 pot up to now (Aug 17th)

1629 int 32x1019 pot are expected at end of the run

Summarybull The OPERA experiment is taking data in the CNGS beambull 178x1019 pot were collected during the first physics run in

2008bull The analysis of 2008 data is in progressbull The evaluation of total efficiencies is ongoingbull In 2009 run 154x1019pot were already collected

ndash 45x1019 pot are requestedndash 32x1019 pot are expected at the end of the runndash Detection of ~2 nu-tau events is expectedhellipSOON

BACKUP

OPERA signal and background

decay channel

BR () Signal m2 = 25 x 10-3 eV2

Background

177 29 017

e 178 35 017

h 495 31 024

3h 150 09 017

Total 104 075

Full mixing 5 years run 45x1019 pot year

Main background sources bull Production and decay of charmed particles bull Hadron re-interactionsbull Large angle muon scattering

Pt estimation for charm candidate 72853

Tau background by D0

bull Neutral charmed particle decay vertex mistaken as primary vertex in events where only a muon and D0

are produced at primary vertex

channel

Cut on the invariant mass to be used to reduce this background source

Pt cut

Daughter particle of τ

Daughter particle of hadronic re-interactions

Pt(GeVc) Pt(GeVc)

MC MC

• Status and results from OPERA
• OPERA
• CNGS beam
• Slide 4
• OPERA detector
• Parallel analysis of ECC bricks
• Swiss scanning station in LHEP Bern
• Slide 8
• Located neutrino interactions
• Status of event location in ECC for 2008 run
• Analysis for located events
• Slide 12
• Slide 13
• Slide 14
• Charm candidates
• Activities of Swiss group in OPERA analysis
• Study of hadronic background for tau
• Study of hadronic background for tau (2)
• Gamma detection and π0 reconstruction
• Status and prospect for the on-going 2009 run
• Summary
• Backup
• Slide 23
• Slide 24
• Slide 25
• Pt cut

Gamma detection and π0 reconstruction

E ~05 GeV

E ~81 GeV

2 e-showers give a reconstructed mass ~ 160 MeVc2

70 of 1-prong tau hadronic decays include p0Important to detect gamma from tau decay to improve SN

We are working on gamma detection from nu-mu interactions to prove the methodπ0 reconstruction is in progress

g e-pair

Status and prospect for the on-going 2009 run

bull 154x1019 pot have been already collected up to Aug 17thbull 45x1019 pot are requested ~2 tau events are expected to be

detected

2006 0076x1019 pot 0 int Commissioning

2007 0082x1019 pot 38 int Commissioning

2008 178x1019 pot 1663 int First physics run

2009 154x1019 pot up to now (Aug 17th)

1629 int 32x1019 pot are expected at end of the run

Summarybull The OPERA experiment is taking data in the CNGS beambull 178x1019 pot were collected during the first physics run in

2008bull The analysis of 2008 data is in progressbull The evaluation of total efficiencies is ongoingbull In 2009 run 154x1019pot were already collected

ndash 45x1019 pot are requestedndash 32x1019 pot are expected at the end of the runndash Detection of ~2 nu-tau events is expectedhellipSOON

BACKUP

OPERA signal and background

decay channel

BR () Signal m2 = 25 x 10-3 eV2

Background

177 29 017

e 178 35 017

h 495 31 024

3h 150 09 017

Total 104 075

Full mixing 5 years run 45x1019 pot year

Main background sources bull Production and decay of charmed particles bull Hadron re-interactionsbull Large angle muon scattering

Pt estimation for charm candidate 72853

Tau background by D0

bull Neutral charmed particle decay vertex mistaken as primary vertex in events where only a muon and D0

are produced at primary vertex

channel

Cut on the invariant mass to be used to reduce this background source

Pt cut

Daughter particle of τ

Daughter particle of hadronic re-interactions

Pt(GeVc) Pt(GeVc)

MC MC

• Status and results from OPERA
• OPERA
• CNGS beam
• Slide 4
• OPERA detector
• Parallel analysis of ECC bricks
• Swiss scanning station in LHEP Bern
• Slide 8
• Located neutrino interactions
• Status of event location in ECC for 2008 run
• Analysis for located events
• Slide 12
• Slide 13
• Slide 14
• Charm candidates
• Activities of Swiss group in OPERA analysis
• Study of hadronic background for tau
• Study of hadronic background for tau (2)
• Gamma detection and π0 reconstruction
• Status and prospect for the on-going 2009 run
• Summary
• Backup
• Slide 23
• Slide 24
• Slide 25
• Pt cut

Status and prospect for the on-going 2009 run

bull 154x1019 pot have been already collected up to Aug 17thbull 45x1019 pot are requested ~2 tau events are expected to be

detected

2006 0076x1019 pot 0 int Commissioning

2007 0082x1019 pot 38 int Commissioning

2008 178x1019 pot 1663 int First physics run

2009 154x1019 pot up to now (Aug 17th)

1629 int 32x1019 pot are expected at end of the run

Summarybull The OPERA experiment is taking data in the CNGS beambull 178x1019 pot were collected during the first physics run in

2008bull The analysis of 2008 data is in progressbull The evaluation of total efficiencies is ongoingbull In 2009 run 154x1019pot were already collected

ndash 45x1019 pot are requestedndash 32x1019 pot are expected at the end of the runndash Detection of ~2 nu-tau events is expectedhellipSOON

BACKUP

OPERA signal and background

decay channel

BR () Signal m2 = 25 x 10-3 eV2

Background

177 29 017

e 178 35 017

h 495 31 024

3h 150 09 017

Total 104 075

Full mixing 5 years run 45x1019 pot year

Main background sources bull Production and decay of charmed particles bull Hadron re-interactionsbull Large angle muon scattering

Pt estimation for charm candidate 72853

Tau background by D0

bull Neutral charmed particle decay vertex mistaken as primary vertex in events where only a muon and D0

are produced at primary vertex

channel

Cut on the invariant mass to be used to reduce this background source

Pt cut

Daughter particle of τ

Daughter particle of hadronic re-interactions

Pt(GeVc) Pt(GeVc)

MC MC

• Status and results from OPERA
• OPERA
• CNGS beam
• Slide 4
• OPERA detector
• Parallel analysis of ECC bricks
• Swiss scanning station in LHEP Bern
• Slide 8
• Located neutrino interactions
• Status of event location in ECC for 2008 run
• Analysis for located events
• Slide 12
• Slide 13
• Slide 14
• Charm candidates
• Activities of Swiss group in OPERA analysis
• Study of hadronic background for tau
• Study of hadronic background for tau (2)
• Gamma detection and π0 reconstruction
• Status and prospect for the on-going 2009 run
• Summary
• Backup
• Slide 23
• Slide 24
• Slide 25
• Pt cut

Summarybull The OPERA experiment is taking data in the CNGS beambull 178x1019 pot were collected during the first physics run in

2008bull The analysis of 2008 data is in progressbull The evaluation of total efficiencies is ongoingbull In 2009 run 154x1019pot were already collected

ndash 45x1019 pot are requestedndash 32x1019 pot are expected at the end of the runndash Detection of ~2 nu-tau events is expectedhellipSOON

BACKUP

OPERA signal and background

decay channel

BR () Signal m2 = 25 x 10-3 eV2

Background

177 29 017

e 178 35 017

h 495 31 024

3h 150 09 017

Total 104 075

Full mixing 5 years run 45x1019 pot year

Main background sources bull Production and decay of charmed particles bull Hadron re-interactionsbull Large angle muon scattering

Pt estimation for charm candidate 72853

Tau background by D0

bull Neutral charmed particle decay vertex mistaken as primary vertex in events where only a muon and D0

are produced at primary vertex

channel

Cut on the invariant mass to be used to reduce this background source

Pt cut

Daughter particle of τ

Daughter particle of hadronic re-interactions

Pt(GeVc) Pt(GeVc)

MC MC

• Status and results from OPERA
• OPERA
• CNGS beam
• Slide 4
• OPERA detector
• Parallel analysis of ECC bricks
• Swiss scanning station in LHEP Bern
• Slide 8
• Located neutrino interactions
• Status of event location in ECC for 2008 run
• Analysis for located events
• Slide 12
• Slide 13
• Slide 14
• Charm candidates
• Activities of Swiss group in OPERA analysis
• Study of hadronic background for tau
• Study of hadronic background for tau (2)
• Gamma detection and π0 reconstruction
• Status and prospect for the on-going 2009 run
• Summary
• Backup
• Slide 23
• Slide 24
• Slide 25
• Pt cut

BACKUP

OPERA signal and background

decay channel

BR () Signal m2 = 25 x 10-3 eV2

Background

177 29 017

e 178 35 017

h 495 31 024

3h 150 09 017

Total 104 075

Full mixing 5 years run 45x1019 pot year

Main background sources bull Production and decay of charmed particles bull Hadron re-interactionsbull Large angle muon scattering

Pt estimation for charm candidate 72853

Tau background by D0

bull Neutral charmed particle decay vertex mistaken as primary vertex in events where only a muon and D0

are produced at primary vertex

channel

Cut on the invariant mass to be used to reduce this background source

Pt cut

Daughter particle of τ

Daughter particle of hadronic re-interactions

Pt(GeVc) Pt(GeVc)

MC MC

• Status and results from OPERA
• OPERA
• CNGS beam
• Slide 4
• OPERA detector
• Parallel analysis of ECC bricks
• Swiss scanning station in LHEP Bern
• Slide 8
• Located neutrino interactions
• Status of event location in ECC for 2008 run
• Analysis for located events
• Slide 12
• Slide 13
• Slide 14
• Charm candidates
• Activities of Swiss group in OPERA analysis
• Study of hadronic background for tau
• Study of hadronic background for tau (2)
• Gamma detection and π0 reconstruction
• Status and prospect for the on-going 2009 run
• Summary
• Backup
• Slide 23
• Slide 24
• Slide 25
• Pt cut

OPERA signal and background

decay channel

BR () Signal m2 = 25 x 10-3 eV2

Background

177 29 017

e 178 35 017

h 495 31 024

3h 150 09 017

Total 104 075

Full mixing 5 years run 45x1019 pot year

Main background sources bull Production and decay of charmed particles bull Hadron re-interactionsbull Large angle muon scattering

Pt estimation for charm candidate 72853

Tau background by D0

bull Neutral charmed particle decay vertex mistaken as primary vertex in events where only a muon and D0

are produced at primary vertex

channel

Cut on the invariant mass to be used to reduce this background source

Pt cut

Daughter particle of τ

Daughter particle of hadronic re-interactions

Pt(GeVc) Pt(GeVc)

MC MC

• Status and results from OPERA
• OPERA
• CNGS beam
• Slide 4
• OPERA detector
• Parallel analysis of ECC bricks
• Swiss scanning station in LHEP Bern
• Slide 8
• Located neutrino interactions
• Status of event location in ECC for 2008 run
• Analysis for located events
• Slide 12
• Slide 13
• Slide 14
• Charm candidates
• Activities of Swiss group in OPERA analysis
• Study of hadronic background for tau
• Study of hadronic background for tau (2)
• Gamma detection and π0 reconstruction
• Status and prospect for the on-going 2009 run
• Summary
• Backup
• Slide 23
• Slide 24
• Slide 25
• Pt cut

Pt estimation for charm candidate 72853

Tau background by D0

bull Neutral charmed particle decay vertex mistaken as primary vertex in events where only a muon and D0

are produced at primary vertex

channel

Cut on the invariant mass to be used to reduce this background source

Pt cut

Daughter particle of τ

Daughter particle of hadronic re-interactions

Pt(GeVc) Pt(GeVc)

MC MC

• Status and results from OPERA
• OPERA
• CNGS beam
• Slide 4
• OPERA detector
• Parallel analysis of ECC bricks
• Swiss scanning station in LHEP Bern
• Slide 8
• Located neutrino interactions
• Status of event location in ECC for 2008 run
• Analysis for located events
• Slide 12
• Slide 13
• Slide 14
• Charm candidates
• Activities of Swiss group in OPERA analysis
• Study of hadronic background for tau
• Study of hadronic background for tau (2)
• Gamma detection and π0 reconstruction
• Status and prospect for the on-going 2009 run
• Summary
• Backup
• Slide 23
• Slide 24
• Slide 25
• Pt cut

Tau background by D0

bull Neutral charmed particle decay vertex mistaken as primary vertex in events where only a muon and D0

are produced at primary vertex

channel

Cut on the invariant mass to be used to reduce this background source

Pt cut

Daughter particle of τ

Daughter particle of hadronic re-interactions

Pt(GeVc) Pt(GeVc)

MC MC

• Status and results from OPERA
• OPERA
• CNGS beam
• Slide 4
• OPERA detector
• Parallel analysis of ECC bricks
• Swiss scanning station in LHEP Bern
• Slide 8
• Located neutrino interactions
• Status of event location in ECC for 2008 run
• Analysis for located events
• Slide 12
• Slide 13
• Slide 14
• Charm candidates
• Activities of Swiss group in OPERA analysis
• Study of hadronic background for tau
• Study of hadronic background for tau (2)
• Gamma detection and π0 reconstruction
• Status and prospect for the on-going 2009 run
• Summary
• Backup
• Slide 23
• Slide 24
• Slide 25
• Pt cut

Pt cut

Daughter particle of τ

Daughter particle of hadronic re-interactions

Pt(GeVc) Pt(GeVc)

MC MC

• Status and results from OPERA
• OPERA
• CNGS beam
• Slide 4
• OPERA detector
• Parallel analysis of ECC bricks
• Swiss scanning station in LHEP Bern
• Slide 8
• Located neutrino interactions
• Status of event location in ECC for 2008 run
• Analysis for located events
• Slide 12
• Slide 13
• Slide 14
• Charm candidates
• Activities of Swiss group in OPERA analysis
• Study of hadronic background for tau
• Study of hadronic background for tau (2)
• Gamma detection and π0 reconstruction
• Status and prospect for the on-going 2009 run
• Summary
• Backup
• Slide 23
• Slide 24
• Slide 25
• Pt cut