atlas and cms activities

LC Workshop April 2002 ATLAS & CMS prospects Albert De Roeck (CERN)

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ATLAS and CMS activities

Albert De RoeckCERN

ECFA/DESY meeting St Malo 12-15 April 2002


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LHC Prospects• New date for first beams/collisions: 1/4/2007• Initial physics run starts in 2007 ~10 fb-1 (2.1033cm-2 s-1)• Depending on the evolution: 200-300 fb-1 in 5-6 years (3.4-10.1033cm-2 s-1 )• Studies ongoing for 1.1035cm-2 s-1 (SLHC)

– Needs changes in machine and detectors ~3000 fb-1 in 3-4 years, i.e. by the end of 2010 or so

• CMS & ATLAS preparing for first beam in 2007– Concentrate on hard & software– Main questions are on trigger/DAQ, using gold plated physics

channels– Exploring of new physics studies not main activity now Discovery potential has been demonstrated for key processes

• Planned/existing physics review studies– ATLAS physics TDR exist since 2000, may be redone in 2005– CMS physics TDR planned for 2005, starting to prepare during

2002


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ATLAS and CMS Plans• Common LC/LHC studies

– There is interest but not yet much activity (5-10 people/exp for now)

– We need to start with a fewspecific questions/studies– (Agree on luminosities etc.)

• ATLAS: Global fits using masses of measured particles, to scan and constrain the susy space Expect gain due to sleptons on M0

Add branching ratio & cross section measurements Will be initially based on the ‘old’ LHC benchmark points CMS: interest to start such activity/using new benchmark points

• ATLAS & CMS: check on gain of precise measurements of 01 (and

other gaugino’s) for reconstructing squark masses (mass splitting)• CMS: Combining heavy higgs (LHC) with light higgs (LC)

measurement


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ATLAS and CMS Plans• Benchmark points

– ATLAS: so far study of point E(*) (SPS 2(**)), maybe B (SPS 1a) next

– CMS: point B, C (SPS 3) , E and G for trigger studies and reconstruction points I,L (SPS 4) for heavy Higgs to Tau

( point I could be replaced by SPS1b )– SLHC study: points M, K, H used (no SPS equivalent)– Non-mSUGRA models: take SPS selected points

• CMS: Combined studies of extra dimensions ?

Plan for first results end of June

In the following:• A reminder of LHC reach, relevant for this group• New studies in CMS, e.g. on susy mass reconstruction

(*) BDEGMOPW points (**) Snowmass points & slopes


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Example: LSP from LCImpact of the precise knowledge of the LSP from the LC on the neutralino two and slepton masses

LSP mass LSP mass


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CMS

Visiting IP5… CMS getting into shape


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Example: The CMS experimento Tracking

o Silicon pixelso Silicon strips

o Calorimeterso PbW04 crystals for Electro-magn.o Scintillator/copper for hadronic part

o 4T solenoido Instrumented iron for muon detection

o Jet Energy scale to 1.0%o EM energy scale to 0.1%o Luminosity to better than 5%


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Expected Event rates

0.001 104

(m=1 TeV) H 0.001 104

(m=0.8 TeV)

Process Events/s Events/year Other machines

W e 15 108 104 LEP / 107 Tev

Z ee 1.5 107 107 LEP

0.8 107 104 Tevatron

105 1012 108 Belle/BaBar

QCD jets 102 109 107 pT > 200 GeV

gg~~

tt

bb

Huge event rates:

The LHC will bea W-factory, aZ-factory, a topfactory, a Higgsfactory etc..


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SM Higgs search

Production and decay modes:


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Expected Results for the Higgs

- Will discover the Higgs in the range 100 GeV 1 TeV (if exists)- Precision on the measurement of the mass between 0.1-1%


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H ZZ(*) 4 leptons

• clean signal, mass resolution 1%• precision on muon momentum comes from combining muon chamber with tracker info


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Light Higgs search

If mh < 140 GeV : gg h most promising channel, although BR only 10-3 …

motivation for high resolution ECAL (PbWO4 crystals: 1% at 100 GeV)


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Light Higgs search

Recent: h bb in tth production _

Also results on H


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Hgap gap

b

b -jet

-jet

Exclusive Higgs

A recent development: search for exclusive Higgs production pp p H p

p p

beam

p’

p’

dipoleroman pots

Needs roman pots

Cross section ~ 1 fb Khoze et al.

roman pots

dipole


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Invisible Higgs


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Heavy Higgs

Working hard to cover low tan - high mA region …

COVERED• at large tan , bb A/H and tb H production strongly enhanced!!

• assume Msusy = 1 TeV

• important channels:• A/H • A/H • H • H tb


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Heavy MSSM Higgs search (3)

F. Moortgat

NEW: at low tan , we may exploit the sparticle decay modes:

A, H 20 2

0 4l + ETmiss


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Susy measurements

Atlas physics TDR


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Susy

Mostly complicated decay chains


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Susy

Decay chain example


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Susy discovery LimitsS. Abdoulin


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Susy measurementsAtlas physics TDR: LHC Point 5

m0=100 GeV m1/2=300 GeV tan = 2.1sgn()=+A=300 GeV


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Susy measurementsAtlas physics TDR


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Benchmark points


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Benchmark Points


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99.610 = LSP

186.01±145.8lR

379.72±211.4lL

186.820549qR

358.830570qL

379.140549.7bR

600.5tR522.5bL

412.5tL643.3g

pb 41.41TOTSUSY

Study of point B (SPS1)M. Chiorboli


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Decay chain

p

p

g~

b~

b

b

01

~

02

~ ~

0A

)( sign

10β tan

100m

250m

0

0

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bb~

g~ pp

b~02

01~

(15% bL, 10% bR)

(35 % bL, 22% bR)

(0.2 %)

01

~ ~

(60 %)

Event final state:

• 2 high pt isolated leptons OS

• 2 high pt b jets

• missing Et


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First step: 20 l+l- 1

0

02

~ 01

~

~p

p

g~

b~

b

b

01

~

02

~ ~

GeV 85.32 M

)M)(MM(MM

2

χ

222

χmax01

02

~

~~~~

GeV 1.64 86.00 Mmax

Fit result:

)μM(μ )eM(e -

)μM(e -)μM(e - )μM(μ )eM(e -- Etmiss > 50 GeV

10 fb-1


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Sbottom reconstruction

p

p

g~

b~

b

b

01

~

02

~ ~

Assuming M(10)

known!

p

M

M1p

01

02

~

~

GeV 92 M GeV 75


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Sbottom mass

55.8

GeV 8.1516.4b)~M( 02

Result of fit:

GeV 7.549)b~

M(

GeV 5.522)b~

M(

R

L

Generated masses:

10 fb-1


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Gluino reconstruction

p

p

g~

b~

b

b

01

~

02

~ ~

b)b~

( angle

Etmiss > 150 GeV


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Gluino mass

9.54σ

GeV 7.2631.8bb)χ~M( 02

Result of fit:

GeV 643.3)gM( ~Generated mass:

10 fb-1


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with 60 fb-1

60 fb-1

0.37σ

GeV 3.50.99b)χ~M(bb)χ~M( 02

02

Result of fit:

)bM(-)gM(~~ )bM(-)gM(~~

GeV 6.93)b~

M(-)g~M(

GeV 8.120)b~

M(-)g~M(

R

L

Generated values:


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152.510 = LSP

294.51±193.4lR

546.12±299.6lL

294.820780qR

532.430814qL

545.340771.3bR

800.8tR723.0bL

589.4tL919.8g

Point G

pb 6.00TOTSUSY


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Sbottom peak

6.82

GeV 8.743b)~M( 02

Result of fit:

GeV 3.771)b~

M(

GeV 0.723)b~

M(

R

L

Generated masses:


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Guino peak

7.31σ

GeV 1.909bb)χ~M( 02

Result of fit:

GeV 8.199)g~M(

Generated mass:


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estimation

This needs better understanding of the SM bkg behaviour!

27.9σ

GeV 5.7168.1b)χ~M(bb)χ~M( 02

02

Result of fit:

)bM(-)gM(~~ )bM(-)gM(~~

GeV 5.148)b~

M(-)g~M(

GeV 8.196)b~

M(-)g~M(

R

L

Generated values:


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Conclusions

Point G, with 60 fb-1

• Sbottom and gluino seem to be visible

• estimation of M(l+l-)max

• sbottom reconstruction with Resol. ~ 10 %, but 2 sbottoms not resolved

• gluino reconstruction with Resol. < 10 %

• M(g) - M(b) estimation, independent of M(10), with Err ~ 4 %

Point B, with 10 fb-1

~2~

2~

2~

2~ M)MM)(MM( 0

102

• Maybe we can separate the 2 sbottoms

Point B, with 60 fb-1


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Stop Searches

Stop mass and cross sectionMissing ET and transverse l mass

S/B forSM andSM+SUSY

Channels


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Rare Top Decays

S. Slabospitskydecay production

t ugt cg

1.6 10-3

1.6 10-3

(0.35.) 10-3

(2.122.) 10-3

tutc

2.5 10-5

2.5 10-5

0.4 10-5

3.5 10-5

tuZtcZ

1.6 10-4

1.6 10-4

1.1 10-4

4.8 10-4


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Graviton SearchesTraczyk, Wrochna

KK excitations in the RS model

Search Reach

MG=1000 GeVC=0.01

MG=2000 GeVC=0.01


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physics

• observation: provided efficient measurement of forward scattered protons, one can study high-energy collisions at the LHC

p p

Highlights:• CM energy W up to/beyond 1 TeV (and under control) • Large photon flux F therefore significant luminosity• Complementary (and clean) physics to pp interactions, eg studies of exclusive production of the Higgs boson, W pairs might be possible opens new field of studying very high

energy physics


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Two-photon interactions at the LHC

pp

October 2001 K.Piotrzkowski, Erice Workshop

Physics Menu - Highlights

H0

pb (at W=MH=200 GeV)

pb

tt

pb

nb

All ?

W+W-

+ SUSY processes

+ total cross section ….


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physics

H0

pb (at W=MH=200 GeV)

SUSY: Higgs:

clean signatures: both transversal and longitudinal missing energy !

it cannot be missed!!


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And more…-Precision measurements MW to 15 MeV, Mtop to 1.5 GeV anomalous gauge couplings, sin2W, rare top decays, B-physics, CP violation studies-MSSM Higgs bosons-Extra dimensions-New heavy gauge bosons-Strong interactions in the W sector-Technicolor-Compositeness up to scales of 40 TeV

LHC detectors must be preparedfor the unknown

MSSM Higgs

W massNew W boson

Top quark mass

atlas and cms activities

Documents

cms physics tdr

cms activitiesalbert

heavy higgs lhc

gev light higgs

old lhc benchmark points

cms plansbenchmark pointsatlas

initial physics

sm higgs searchproduction