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The FP420 Project: Physics Potential

The FP420 Project: Physics Potential. Albert De Roeck CERN and University of Antwerp and the IPPP Durham. Exclusive Central Production.

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The FP420 Project: Physics Potential

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  1. The FP420 Project:Physics Potential Albert De Roeck CERN and University of Antwerp and the IPPP Durham

  2. Exclusive Central Production • Selection rules mean that central system is (to a good approx) 0++ If you see a new particle produced exclusively with proton tags you know its quantum numbers • CP violation in the Higgs sector shows up directly as azimuthal asymmetries • Tagging the protons means excellent mass resolution (~ GeV) irrespective of the decay products of the central system. LO QCD backgrounds suppressed • Proton tagging may be the discovery channel in certain regions of the MSSM. • Unique access to a host of interesting QCD processes Very schematically: exclusive central production is a glue – glue collider where you know the beam energy of the gluons - source of pure gluon jets - and central production of any 0++ state which couples strongly to glue is a possibility …

  3. FP420: Detectors at 420m TOTEM (ATLAS/RP220) FP420 Low *: (0.5m): Lumi 1033-1034cm-2s-1 215m: 0.02 <  < 0.2 300/400m: 0.002 <  < 0.02 Detectors in the cold region are needed to access the low  values FP420 R&D Study

  4. FP420 R&D Study • Feasibility study and R&D for the development of detectors to measure protons at 420 m from the IP, during low  optics at the LHC • Main physics aim pp  p+ X + p • Higgs, New physics • QCD/diffractive studies • Photon induced interactions • Study aims • Redesign 420 m (cryostat region) • Mechanics/stability/services for detectors • Tracking detectors to operate close to beam • Fast timing detectors (10-20 picosecond resolution) • RF issues, integration, precision alignment, radiation, resolution,… • Trigger/selection issues/pile-up for highest luminosity To be built/deployed by ATLAS and/or CMS, when successful • Collaboration web page: http://www.fp420.com Excellent collaboration with machine/cryo groups; Keith Potter mediator

  5. Central Exclusive Higgs Production Central Exclusive Higgs production pp p H p : >3 fb (SM) ~10-100 fb (MSSM) -jet E.g. V. Khoze et al ADR et al. M. Boonekamp et al. B. Cox et al. V. Petrov et al… Brodsky et al. gap gap H h p p -jet M = O(1.0 - 2.0) GeV beam dipole A way to get information on the spin of the Higgs dipole p’ FP420 R&D Project http://www.fp420.com p’ roman pots roman pots

  6. Exclusive Higgs production Generator studies with detector cuts b jets : MH = 120 GeV s = 2 fb (uncertainty factor ~ 2.5) MH = 140 GeV s = 0.7 fb MH = 120 GeV :11 signal / O(10) background in 30 fb-1 Standard Model Higgs with detector cuts hep-ph/0207042 H WW* : MH = 120 GeV s = 0.4 fb MH = 140 GeV s = 1 fb MH = 140 GeV :8 signal / O(3) background in 30 fb-1 with detector cuts hep-ph/0505240 • The b jet channel is possible, with a good understanding of detectors and clever level 1 trigger (need trigger from the central detector at Level-1, possibly with O(10) KHz rate) • The WW* (ZZ*) channel is extremely promising : no trigger problems, better mass resolution at higher masses (even in leptonic / semi-leptonic channel)

  7. Higgs Studies • Cross section factor • > 10 larger in MSSM • (high tan) • Few 100 events with ~ 10 background events for 30 fb-1 100 fb Kaidalov et al., hep-ph/0307064 1fb Study correlations between the outgoing protons to analyse the spin-parity structure of the produced boson 120 140 A way to get information on the spin of the Higgs ADDED VALUE TO LHC

  8. Measuring the Azimuthal Asymmetry Khoze et al., hep-ph/0307064 Azimuthal correlation between the tagged protons Allows to eg to differentiate O+ from O-

  9. MSSM Scenario Studies S. Heinemeyer et al to appear MA = 130 GeV tan = 50 Hbb No-mixing scenario Contours of ratio of signal events in the MSSM over the SM

  10. An example of what forward proton tagging can do Mhmax MSSM scenario: Hbb (mA=120 GeV, tan = 40, 150 fb-1) Cox, Loebinger and Pilkington arXiv:0709.3035 Invariant mass calculated with the two protons Events / 1 GeV Taking into account acceptance, trigger efficiencies etc. Mass GeV Also promising studies in Haa (NMSSM; J. Gunion et al.)

  11. “lineshape analysis” J. Ellis et al. hep-ph/0502251 Scenario with CP violation in the Higgs sector and tri-mixing Needs ~ 1 GeV mass resolution and a few 100 pb-1 for this scenario

  12. Experimental issues at nominal luminosity Pile-up • Can be reduced by • Correlations between central detector and RP measurements • Vertices • Event multiplicities • Fast Timing ( K. Piotrzkowski) Detailed studies in the CMS/TOTEM LOI LHCC-2006-039 talk this morning Trigger For Hbb Allow higher L1 rate O(10) KHz and use protons from tagger at HLT?

  13. e.g. arXiv:0705.3804 CDF Also: Observation of exclusive 2 photon and di-lepton events in CDF

  14. Long Lived Gluinos at the LHC P. Bussey et al hep-ph/0607264 Gluino mass resolution with 300 fb-1 using forward detectors and muon system The event numbers includes acceptance in the FP420 detectors and central detector, trigger… Measure the gluino mass with a precision (much) better than 1%

  15. Exotics Anomalous WW Production? Alan White: theory of supercritical pomeron reggeized gluon+many (infinite) wee gluons • color sextet quarks required by asymptotic freedom, have strong colour charge, (at least) few 100 GeV constituent mass • Sextet mesons  EWSB • UDD neutron dark matter candidate • Explain high energy cosmic rays, Knee? • Color sextet quarks couple strongly to W and Z and to the pomeron • Phenomenology: Anomalous production of WW when above threshold ie. At the LHC (with possibly some onset already detectable at the Tevatron color color triplets sextets u c t U d s b D • Measure exclusive WW,ZZ cross sections in DPE at the LHC Expected cross section to be orders of magnitude larger than in SM

  16. CMS Near beam Detectors p p Photon-photon and photon-proton @ LHC Process WWA spectrum • Extensive Program •   , ee QED processes •   QCD (jets..) •   ZZ/WW anomalous couplings •   top pairs •   Higgs •   Charginos • … …and p

  17. QED Processes for Alignment

  18. FP420 CERN-LHCC-2005-025 LHCC-I-015 FP420 : An R&D Proposal to Investigate the Feasibility of Installing Proton Tagging Detectors in the 420m Region at LHC FP420 R&D Funding (ATLAS & CMS) : “The panel believed that this offers a unique opportunity to extend the potential of the LHC and has the potential to give a high scientific return.” - UK PPRP (PPARC) R&D funding : £500k from UK (Silicon, detector stations, beam pipe + LHC optics and cryostat design), $100k from US(QUARTIC, Andrew Brandt/UTA), €100k Belgium (+Italy / Finland) (mechanics)

  19. Schematic of Extremely High Precision Proton Spectrometer CMS High precision (~ 5 m) BPM High precision (~ 5m) BPM 420m of vacuum pipe 120m of 8T dipoles Precision ~ 5 m on track displacement and ~ 1 rad on angle w.r.t. beam. Layout schematic ... Still being optimized

  20. Final cryostat design launched (TS/MME group at CERN)

  21. Integration of the moving beampipe and detectors ATM BPM Line X Bus Bar Cryostat Vacuum Space BPM QRL Fixed Beampipe ATM Pockets Transport side Vacuum Space Benoît Florins, Krzysztof Piotrzkowski, Guido Ryckewaert

  22. OCTOBER

  23. FP420 test beam 11-16 October 2007

  24. Full 3D silicon blades response PRELIMINARY 180 GeV/c pions Telescope pitch 50x50mm2 Vbias= 30V x-y 3D correlation with Si telescope Single detector Hit map Time Over Threshold FP420 Test Beam 11-16 October 07

  25. Working on the test-beam (Oct 07)

  26. Summary • Near beam detectors at 420m will extend the physics potential of the central detectors ATLAS and CMS. • Main physics aim pp  p+ X + p • Higgs, in particular in the MSSM, New physics, Exotic physics • QCD/diffractive studies • Photon induced interactions • Consider FP420 an ‘extension’ of the ATLAS/CMS baseline detectors • R&D program ongoing since a few years. Next steps include • R&D conclusions report of FP420, to be submitted to CMS & ATLAS  complete draft for November, including costing. • Detectors in testbeam: July at FNAL, October at CERN • Collect feedback for ATLAS and CMS for LOI/TDR preparation, if project approved within the collaboration. • Start-up of discussions within CMS &ATLAS to include FP420 detectors. Referees installed for CMS. Decision within the next few months • Installation at LHC: Earliest during 2009-2010 Shutdown

  27. RESERVE

  28. Preliminary planning of interconnection: Days 1 3 5 7 9 11 13 15 17 19 21 23 25 Dismantling of interconnection Removal of C.C. Reconditioning of interconnection Installation of FP420 cryostat. Interconnection Last operation & commissioning. T. Colombet (At-MCS)

  29. Summary I Very active R&D programme Proton optics and LHC accelerator issues Cryogenic by-pass Moving pipe mechanics Track detectors (3D Si) and precision mounting. Beam position monitors Fast timing detectors Reference time signal Infrastructure DAQ and Triggers Simulations Backgrounds Preliminary cost estimate Timeline R&D on FP420: tiny but v.high precision tracking, timing, BPM Best particle spectrometer ever, using part of LHC. Important gain in physics potential for modest cost. Committed group that is interested to pursue this project within CMS CMS groups in FP420:Antwerp, CERN, Fermilab, (Helsinki,) Lawrence Livermore (LLNL), Louvain, Moscow(ITEP), Protvino, Rio de Janeiro, Rockefeller, Torino/Novara Next step: R&D conclusions report of FP420, to be submitted to CMS & ATLAS (and LHCC?) complete draft for August including costing

  30. Test of Theoretical Predictions “Durham” group: Uncertainties in skewed gluon distributions, gluon , Sudakov form factors. Claim uncertainty ~ 3. Some central exclusive production (QCD) processes are accessible at the Tevatron and are studied in CDF: Of these, is the cleanest as FS not strongly interacting MGA et al., hep-ex/0511057 2 EM showers No tracks Khoze, Martin and Ryskin, hep-ph/0111078, Eur.Phys.J. C23: 311 (2002) KMR+Stirling hep-ph/0409037 Implication: Exclusive Higgs production must happen

  31. Simulation of beam line/detectors • Two tools for beam transport available (FPTRACK, HECTOR) used for • acceptance studies • mass resolution studies • alignment studies NB HECTOR in FAMOS and CMSSW (developed by CMS-Louvain group and interfaced to CMSSW by IHEP-Protvino) • G4 simulation of the beam line under development • geometry set up • shower formation coming soon • suitable for integration in CMS full simulation? • G4 simulation of the detector region available (ITEP Moscow/Antwerp) • effect of multiple interactions quantified; results used to finalize single detector geometry and station number and layout • track reconstruction under development • integrated into CMSSW

  32. J. de Faverau, K. Piotrzkowski, X. Rouby, Louvain

  33. ATM Reshuffling Module. X Line Superfluid He (X) Line. Existing raw interfaces

  34. Assembly Detector stations D. Dattola, INFN-Torino

  35. Detector Box (In work) QUARTIC Silicon 3D GASTOF D. Dattola, INFN-Torino

  36. Detector optimization ongoing with Geant4 tools

  37. Fast Timing Detectors Include high precision timing counters. Suggested in Tevatron LOI: Quartz Cerenkov + ~ Microchannel PMT Then said 30 ps(?). Now tested (Japanese Gp)  10 ps Other option: Gas Cerenkov Check that p’s came from same interaction vertex (& as central tracks) x tR tL t_int t tL z_vtx tR z Expected to be particularly useful/essential at high luminosity/pile-up

  38. Before inserting bars and wrapping QUARTIC (Fermilab) GASTOF (Louvain) SiPMT + Quartz also studied QUARTICs : 8 measurements/proton 2 in beam  16 measurements on “timetrack” Could have two GASTOFs + 2 QUARTICS. Resolution still dominated by electronics ... can do better Longer term possibilities (Tracker upgrade time): Develop thin (Si, 3D?) fast timing layers. Pads ~ cm2. Find true event time and match with t(pp). Further pile-up rejection ~ 20 may be possible. Forward discs also: reject events with forward tracks Had two generations of detector and Electronics in Fermilab test beam Sept 2006 and Mar 2007 ... next run July 07.

  39. Triggers for Exclusive Processes •  Detectors at 420m can be included in the HLT •  Would need to increase L1 latency for inclusion in L1, which might be possible in special runs • (use post-L1Accept event buffers as pre-L1Accept storage) • For standard CMS running triggering with forward detectors has been studied in great detail, see trigger appendix in CMS PTDR-II • CMS trigger menus in PTDR-II foresee 1% of the bandwidth on L1 and HLT for a dedicated forward detectors trigger stream • H(140GeV) -> WW: • Can trigger ~20% of events via the standard L1 muon trigger • H(120GeV) -> bb: • Can trigger 10% of the events via the standard L1 muon trigger • Can gain an additional 10% from the jet trigger when combining jet trigger and tag at 220m, because can lower dijet ET thresholds substantially, to about 40GeV per jet, for bandwidth limit of 1kHz • In order to retain this 10% gain from the jet trigger on L1 and stay within bandwidth limit of 1Hz, • need FP420 information on HLT Last word on trigger not yet said…

  40. TOTEM d(epeXp)/dxL [nb] det@420 xL=P’/Pbeam= 1-x Pile-up Number of PU events with protons within acceptance of near-beam detectors on either side: ~2 % with p @ 420m ~6 % with p @ 220m Translates into a probability of obtaining a fake DPE signature caused by protons from PU: Eg at 2x 1033 cm-2s-1 10% probability for a fake DPE signature for any background source that looks identical to the signal in the central CMS detector only. This is independent of the type of signal. Depends critically on the leading proton spectrum at the LHC which in turn depends on size of soft rescattering effects (rapidity gap survival factor) !

  41. Pile-up Can be reduced by: Requiring correlation between ξ, M measured in the central detector and ξ, Mmeasured by the near-beam detectors Fast timing detectors that can determine whether the protons seen in the near-beam detector came from the same vertex as the hard scatter within 3mm Condition that no second vertex be found within 3mm vertex window left open by fast timing detectors Additional cuts exploiting difference in multiplicity between diff signal and non-diff background ; 12 s = M2 incl QCD di-jets + PU CEP H(120) bb (jets) (p tagger) CEP of H(120 GeV) → b bbar and H(140 GeV) → WW: S/B of unity for a SM Higgs M(2-jets)/M(p’s)

  42. Machine induced backgrounds • Beam haloinduced bybetatron cleaningcollimators in contact with collimator group (Assman et al.) • Beam haloinduced bymomentum cleaningcollimators available (IHEP-Protvino) • Beam gas results from Protvino group to come • IP secondaries simulation results from machine group with tracking down to 214m available, on going extention down to 420m  Beam Halo induced by beta-cleaning collimators • Count hits at FP420 location in x, x’, y, y’, dp/p until all protons are absorbed at collimators or other aperture limits (not FP420) • Normalization to the expected loss rate • Conclusion: at 10 sigma (3 mm) we may have a problem! • we move out at 15 sigma • we propose to move IN collimators

  43. HV-LV supplies • Investigated 3 commercial solutions (CAEN, Eplax, Wiener) and ‘home-made’ option. CAEN and Wiener have ‘off-the-shelf’ radiation-tolerant products • LV/HV crates under the adjacent magnets • CAEN solution is an all-in-tunnel with short HV-LV cables • Wiener solution has LV in tunnel and HV in counting room • CAEN ok up to 140Gy (Atlas certified) except for A3501 (HV) which may need to be tested (though same components as A3540, tested ok by Atlas) • Some customization needed for CAEN solution: • CAN modules (transmission speed over 500m cable), currently being investigated • A3501 (HV), may need to increase max HV to 120 V • Wiener not radiation-tested but advertised as radiation-tolerant (Wiener ”ready to test acccording to instructions”) Radiation!

  44. CAEN solution Cable: 500m A3009 LV A3501 HV A3009 LV A3501 HV A3486 48V Power • Delivery not possible before summer 2008 due to LHC production bottleneck. Only few samples by mid 2007. • CAN bus link over 500++m require slow down to 250kbit/s. This is not yet tested but should be ok. Requires modification of firmware: • High voltage only up to 120V (requires modification from 100V nominal) H. Larsen, INFN-Torino

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