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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. Rich program for Forward Physics at LHC. F 2 p at very low x. Diffraction. Evidence for CEP ?. Saturation at very low x ?.
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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
Rich program for Forward Physics at LHC F2p at very low x Diffraction Evidence for CEP? Saturation at very low x ? Underlying event/Multiple interactions Long dist. Correl. in rap. (need to cover fwd region) Huge differences for diff. generators and diff. tunes Two-photon interactions - Absolute lumi calibration - Calibration, resolution for FPS - Factorization breaking in hard diffr. Average mult. transv. to leading jet at LHC [C.Buttar et al., HERA-LHC proc.]
H b, W b, W Central Exclusive Diffraction: Higgs production - 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 detector Discovery difficult in SM but well possible in MSSM Pile-up is issue for Diffraction at LHC! 5sigma contours:H→bb, mhmax scen., μ=-500GeV [Heinemayer, Khoze, Ryskin, Stirling, M.T., Weiglein] [CMS-Totem : Prospects for Diffractive and Fwd physics at LHC] Log S/Bpu Rejection power Offline cuts But can be kept under control !
Forward detectors at LHC TOTEM -T2 CASTOR ZDC/FwdCal TOTEM-RP FP420 I P 5 14 m 16 m 14 0 m 1 4 7 m - 2 2 0 m 4 2 0 m I P 1 LUCID ZDC ALFA/RP220 FP420
Proton taggers for high luminosity TOTEM-RP FP420 I P 5 14 m 16 m 14 0 m 1 4 7 m - 2 2 0 m 4 2 0 m I P 1 RP220 FP420
detectors@420m Proton taggers for high luminosity • At CMS: TOTEM: Roman Pots at 147 and 220m • Excellent coverage in x and t at low luminosity optics (b*=90, 1540m) • Coverage 0.02<x<0.2 at high luminosity optics (b*=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<x<0.02 (high luminosity optics only) Logx TOTEM - RP220 b*=0.5 FP420 xL=P’/Pbeam= 1-x Logt
Michigan State Univ. Univ. of Chicago, Argonne (timing det.)
How to measure the protons TOTEM on CMS side RP220 on ATLAS side FP420 • Cold region • of LHC • Too far for • L1 trigger FP420 (ATLAS)
Roman Pot acceptances for Totem and CMS [CMS-TOTEM: Prospects for Diffractive and Fwd physics at LHC]
Acceptance for RP220 and FP420 at ATLAS [W.Plano and P.Bussey, FP420]
Integration into LHC structure Diffraction protons deflected horizontally and away from the ring Only horizontal pots from outside needed! [A.Kupčo, RP220] BEAM 2 Diffraction p’s deflected horizontally but inside the ring
Tracking - Resolutions Requirements: 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]
Candidates for tracking detectors • Baseline: “3D” Pixels detectors (S. Parker) Under development for FP420 Stanford, VTT, Sintef • Backup: Silicon strips: Experienced technology Canberra, Hamamatsu 3D (Stanford) 50mm strips (Canberra) Semi-3D detector (VTT, Finland) Readout chip (ATLAS) Jean-François Genat, RP220 meeting, Oct 17-19th 2007 Krakow, Poland
30 Current (nA) 25 20 15 One strip 10 5 0 1 31 61 91 121 151 181 211 Voltage (V) -5 Silicon strips tests in Prague (July 2007) 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
Test stand at Saclay • - 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 Jean-François Genat, RP220 meeting, Oct 17-19th 2007 Krakow, Poland
Fast timing detectors 200 GHz electronics MultiChannel Plates Simul. tools Fast 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 [A.Kupčo and M.T] 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
Level 1 Trigger FP420: 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: [A.Pilkington, FP420] RP220 L1 trigger study CMS-TOTEM L1 trigger STUDY ETjet > 40 && RP220-1side [A.Kupčo, RP220] Total reduction: 10 (RP) x 2 (jet isol) x 2 (2 jets same hemisph as p) = 40 [M.Grothe et al., CMS Note 2006-054]
RP220 in L1 [P. Le Du, RP220]
Design for RP220 Design for RP220 not yet fixed. Still need to consider: • 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
Machine induced background Horizontal beam profiles for nominal beam optics and momentum spread σbeam1 = 250 μm σbeam2 = 180 μm RP220: SIGNAL/Background ~ 10
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!