status of rp220 project
DESCRIPTION
Status of RP220 project. Marek Taševský (Physics Inst. Prague) Forward Physics workshop - Antwerp 25/10 2007. Forward and diffraction physics RP220 project. Rich program for Forward Physics at LHC. F 2 p at very low x. Diffraction. Evidence for CEP ?. Saturation at very low x ?. - PowerPoint PPT PresentationTRANSCRIPT
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Status of RP220 project
Marek Taševský (Physics Inst. Prague)
Forward Physics workshop - Antwerp 25/10 2007
Forward and diffraction physics
RP220 project
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Rich program for Forward Physics at LHC
Diffraction
F2p at very low x
Two-photon interactions
- Absolute lumi calibration- Calibration, resolution for FPS- Factorization breaking in hard diffr.
Underlying event/Multiple interactions
Long dist. Correl. in rap.(need to cover fwd region)
Huge differences for diff.generators and diff. tunes
Average mult. transv. to leading jet at LHC
Saturation at very low x ?
Evidence for CEP?
[C.Buttar et al., HERA-LHC proc.]
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Central Exclusive Diffraction: Higgs production
b, W
b, WH
- Khoze, Martin, Ryskin hep-ph/0111078- Central system is 0++
- If you see a new particle produced exclusively and with proton tags you know its quantum numbers- Roman Pots give much better mass resolution than central detectorDiscovery difficult in SM but well possible in MSSM
Pile-up is issue for Diffraction at LHC!
But can be kept under control !
5sigma contours:H→bb, mhmax scen., μ=-500GeV [Heinemayer, Khoze, Ryskin, Stirling, M.T., Weiglein]
Log S/Bpu
Offline cuts
Rejectionpower
[CMS-Totem : Prospects for Diffractive and Fwd physics at LHC]
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Forward detectors at LHC
14 m 16 m 14 0 m 1 4 7 m - 2 2 0 m 4 2 0 m
I P 1
I P 5
TOTEM -T2 CASTOR ZDC/FwdCal TOTEM-RP FP420
LUCID ZDC ALFA/RP220 FP420
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Proton taggers for high luminosity
14 m 16 m 14 0 m 1 4 7 m - 2 2 0 m 4 2 0 m
I P 1
I P 5
TOTEM-RP FP420
RP220 FP420
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Proton taggers for high luminosity • At CMS: TOTEM: Roman Pots at 147 and 220m Excellent coverage in and t at low luminosity optics (*=90, 1540m) Coverage 0.02<<0.2 at high luminosity optics (*=0.5m)
• At ATLAS: RP220 Roman Pots (of Totem design) at 220m Coverage similar to TOTEM at high luminosity optics
• At CMS and ATLAS: FP420: R&D project, aim to instrument region at 420m 0.002<<0.02 (high luminosity optics only)
detectors@420m
FP420
TOTEM-
RP220
xL=P’/Pbeam=
Log
Logt
*=0.5
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Michigan State Univ.
Univ. of Chicago, Argonne (timing det.)
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TOTEM on CMS sideRP220 on ATLAS sideFP420
How to measure the protons
• Cold region of LHC• Too far for L1 trigger FP420
(ATLAS)
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Roman Pot acceptances for Totem and CMS
[CMS-TOTEM: Prospects for Diffractive and Fwd physics at LHC]
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Acceptance for RP220 and FP420 at ATLAS
[W.Plano and P.Bussey, FP420]
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Integration into LHC structure Diffraction protonsdeflected horizontallyand away from the ringOnly horizontal pots from outside needed!
BEAM 2
Diffractionp’s deflectedhorizontallybut insidethe ring
[A.Kupčo, RP220]
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Tracking - ResolutionsRequirements:
Close to the beam => edgeless detectors
High lumi operation => very radiation hard Beam en.smearing σE = 0.77 GeV
Few μm precision, 1μrad precision Beam spot smearing σx,y = 10 μm
Suppress pile-up => add fast timing det. Detector angular resolution = 1, 2 μrad
ATLAS, 1.5 mm (220) and 5 mm (420) from beam
[P.Bussey, FP420]
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Candidates for tracking detectors
• Baseline: “3D” Pixels detectors (S. Parker)Under development for FP420Stanford, VTT, Sintef
• Backup: Silicon strips:Experienced technologyCanberra, Hamamatsu
Jean-François Genat, RP220 meeting, Oct 17-19th 2007 Krakow, Poland
Readout chip (ATLAS)
50m strips (Canberra) Semi-3D detector (VTT, Finland)
3D (Stanford)
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Silicon strips tests in Prague (July 2007)
-5
0
5
10
15
20
25
30 Current (nA)
1 31 61 91 121 151 181 211 Voltage (V)
One strip
Canberra detectors: Reverse current measurement depending on the strip position typically 25 nA OK.Further tests need a full detector wire-bonded and biased.Breakdown voltage 110-130 V OK
Jean-François Genat, RP220 meeting, Oct 17-19th 2007 Krakow, Poland
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Test stand at Saclay
Jean-François Genat, RP220 meeting, Oct 17-19th 2007 Krakow, Poland
- CERN provided a test stand with hybrids equipped with regular ABCDs chips used for the ATLAS SCT thanks to Shaun Roe and Francis Anghinolfi
VME readout module driven by a PC installed at Saclay
- Follow up tests in November:
- Test the ABCDs hybrids provided by CERN at Saclay Get ABCD pedestals
- Wire bond detectors to hybrids at CERN Test bias current
- Test detectors with laser and source at Saclay Get Signal/Noise
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Fast timing detectorsFast development on several fronts for several applications !FP420 and RP220 need to reduce PILE-UP background heavily
At least for H->bb: overlay of 3 events (2 SD + non-diffr. dijets) fakes signal perfectly and
with prob. 1010 x higher than signal. Can be reduced by applying strict central-matching-RP
conditions + fast timing det.
10ps (2-3mm) resol.
may separate different
vertices
Rejection of up to 40
FP420: UTA/ Alberta/ FNAL/ Louvain: first tests with Quartic det. RP220: collaboration with Univ. Chicago, Stony Brook, Argonne and Photonis see also workshop on timing det.: Saclay, 8-9.3.2007, http://www-d0.fnal.gov/royon/timing
200 GHz electronicsMultiChannel Plates Simul. tools
[A.Kupčo and M.T]
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Level 1 TriggerFP420: cannot be put directly into L1 – only in special runs with larger L1 latency
available triggers: 2j, μ (L1 threshold for 2μ is 3 GeV), e, j+lepton
- μ-triggers can save up to 20%
of bb signal
- WW signal saved by lepton triggers
RP220: Can be put into L1: A BIG added value to FP420! Very similar trigger rates
as for foreseen CMS-TOTEM L1 trigger:
CMS-TOTEM L1 trigger STUDY
RP220 L1 trigger study
Total reduction: 10 (RP) x 2 (jet isol) x 2 (2 jets same hemisph as p) = 40
ETjet > 40 && RP220-1side
[A.Pilkington,FP420]
[A.Kupčo,RP220]
[M.Grothe et al., CMS Note 2006-054]
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RP220 in L1
[P. Le Du, RP220]
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Design for RP220
Design for RP220 not yet fixed. Still need to consider:
1) Alignment and calibration: BPMs themselves should be quite precise (about 10 μm?). But we need physics processes to cross-check and also for the detector calibration. The price for that is high: 2 additional vertical RPs.
2) Fast timing detector: not enough space in the current RP (Totem) design because fast timing det. need large radiators to collect a good number of
photons → put movable beam pipe behind RP
3) Size of 3D-Si sensors: what is the best size of sensors in the (x,y) -region of interest wrt yield?
4) L1 trigger: 3D-Si: standard pixel trigger is just YES/NO for the full detector,while we need to know which strip is hit at L1 to measure ξ or mass at L1 →needs to develop a new trigger card. Si-strips: needs to include trigger in ABCNext chip, unfortunately not first
priority for CERN
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Machine induced background
Horizontal beam profiles for nominalbeam optics and momentum spread
σbeam1 = 250 μmσbeam2 = 180 μm
RP220: SIGNAL/Background ~ 10
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RP220 Timetable
In addition to FP420 project, there is a strong complementary program to upgrade the
220 region with horizontal pots at ATLAS, which adds significant value to FP420
• Aim is to submit proposal for a sub-detector upgrade this year for 420 and 220 upgrades
• If accepted by ATLAS (and/or CMS) this would lead to TDR from experiment to LHCC in early 2008
• RP220 Roman Pots and baseline detectors designed to be ready in 2010
• Collaboration between FP420 and RP220 getting more intensive. There was
a common and fruitful meeting in Paris last September
NEW COLLABORATORS WELCOME!
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B A C K U P S L I D E S
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