1 Status of RP220 project Marek Taševský (Physics Inst. Prague) Forward Physics workshop - Antwerp 25/ Forward and diffraction physics RP220 project

2 Rich program for Forward Physics at LHC Diffraction F 2 p 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.]

3 Central Exclusive Diffraction: Higgs production b, W H - Khoze, Martin, Ryskin hep-ph/ Central system is 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! But can be kept under control ! 5sigma contours:H→bb, mhmax scen., μ=-500GeV [Heinemayer, Khoze, Ryskin, Stirling, M.T., Weiglein] Log S/B pu Offline cuts Rejection power [CMS-Totem : Prospects for Diffractive and Fwd physics at LHC]

4 Forward detectors at LHC 14 m 16 m 14 0 m m m m I P 1 I P 5 TOTEM -T2 CASTOR ZDC/FwdCal TOTEM-RP FP420 LUCID ZDC ALFA/RP220 FP420

5 Proton taggers for high luminosity 14 m 16 m 14 0 m m m m I P 1 I P 5 TOTEM-RP FP420 RP220 FP420

6 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) FP420 TOTEM - RP220 x L =P’/P beam =  Log  Logt  *=0.5

7 Michigan State Univ. Univ. of Chicago, Argonne (timing det.)

8 TOTEM on CMS side RP220 on ATLAS side FP420 How to measure the protons Cold region of LHC Too far for L1 trigger FP420 (ATLAS)

9 Roman Pot acceptances for Totem and CMS [CMS-TOTEM: Prospects for Diffractive and Fwd physics at LHC]

10 Acceptance for RP220 and FP420 at ATLAS [W.Plano and P.Bussey, FP420]

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12 Integration into LHC structure Diffraction protons deflected horizontally and away from the ring Only horizontal pots from outside needed! BEAM 2 Diffraction p’s deflected horizontally but inside the ring [A.Kupčo, RP220]

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15 Tracking - Resolutions Requirements: Close to the beam => edgeless detectors High lumi operation => very radiation hard Beam en.smearing σ E = 0.77 GeV Few μm precision, 1μrad precision Beam spot smearing σ x,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]

16 Candidates for tracking detectors Baseline: “3D” Pixels detectors (S. Parker) Under development for FP420 Stanford, VTT, Sintef Backup: Silicon strips: Experienced technology Canberra, Hamamatsu Jean-François Genat, RP220 meeting, Oct 17-19th 2007 Krakow, Poland Readout chip (ATLAS) 50  m strips (Canberra) Semi-3D detector (VTT, Finland) 3D (Stanford)

17 Silicon strips tests in Prague (July 2007) Current (nA) 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 V OK Jean-François Genat, RP220 meeting, Oct 17-19th 2007 Krakow, Poland

18 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

19 Fast timing detectors 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 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, , GHz electronics MultiChannel Plates Simul. tools [A.Kupčo and M.T]

20 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: 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 E T jet > 40 && RP220-1side [A.Pilkington, FP420] [A.Kupčo, RP220] [M.Grothe et al., CMS Note ]

21 RP220 in L1 [P. Le Du, RP220]

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26 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

27 Machine induced background Horizontal beam profiles for nominal beam optics and momentum spread σ beam1 = 250 μm σ beam2 = 180 μm RP220: SIGNAL/Background ~ 10

28 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!

29 B A C K U P S L I D E S

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