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Summary LHC Physics-2006

Summary LHC Physics-2006. Tariq Aziz. TIFR, Mumbai. Workshop on LHC Physics-2006 4-8 September, 2006. Many interesting talks : My sincere apologies to all. pp, B-Physics, CP Violation. ALICE. LHC : 27 km long 100m underground 7TeVX7TeV PP. ATLAS.

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Summary LHC Physics-2006

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  1. Summary LHC Physics-2006 Tariq Aziz TIFR, Mumbai Workshop on LHC Physics-2006 4-8 September, 2006 Many interesting talks : My sincere apologies to all

  2. pp, B-Physics,CP Violation ALICE LHC : 27 km long 100m underground 7TeVX7TeV PP ATLAS General Purpose,pp, heavy ions Heavy ions, pp CMS +TOTEM The Monster is getting ready to Unleash it’s Power A. Gurtu, A. Nikitenko, S. Banerjee

  3. Motivation • High Energy Physics community will like to observe signatures of last corner stone of Standard Model and Physics Beyond it • Large Hadron Collider is built to collide protons at a centre of mass energy of 14 TeV and at a luminosity of 1034 cm-2 s-1 • Two general purpose • detectors, ATLAS and • CMS, are designed to • be sensitive to all new • physics channels • Compact Muon • Solenoid (CMS) is a • 12.5kton detector, • 21.6m long and of • 14.6m in diameter Bunch Crossing 4x107 Hz Proton collision 109 Hz Parton collision New particle production 102 Hz S. Banerjee

  4. LHC Schedule (from June CMS Week) • Experiments told to have beam pipe in place, connected and ready by 1st Sept instead of 1st July 2007. CMS 'Ready to Close' is then be set to 31 August 2007. • Schedule for the 2007 pilot run is: • Date 1= 1 Sept (i-e 2 month delay wrt to official LHC schedule): Expts ready to close with beam pipe installed. • Date 2= Date 1 + 6 weeks (?) = ~ 15 Oct: Expts closed ready for collisions. • Following June Scientific Policy Committee meeting it is decided that in the run of 2007 the LHC will start commissioning with collisions at injection energy (450 GeV). Discussions are going on how much higher in energy the machine can go before the winter shutdown. A. Gurtu

  5. CMS choice: Superconducting Solenoid using a high purity Aluminium stabilized NbTi conductor and cooled by an external cryogenic sysytem Summary of Magnet tests as of 28 August 2006: 4 Tesla field reached ! A. Gurtu, S. Banerjee

  6. CMS: The Most Powerful Magnet Ever Built A. Gurtu

  7. Progress in Cosmic Challenge till 28 August A Slice of Detecor is ready Record 15 M Events at 3.8 and 4T Should give a couple of thousand good tracks We have proven that CMS is a functioning detector A. Gurtu

  8. Tracker is at the heart of the CMS detector: An all silicon solution for the tracking Designed to reconstruct charged tracks with excellent momentum resolution and efficiency better than 98% for |η| < 2.5 Designed to identify tracks coming from detached vertices Largest Silicon Tracker Ever Built 154000Stripmodules with 9.6 million readout channels 1440 Pixel modules with 66 million readout channels S. Banerjee

  9. New Analysis Developments from CMS http://cmsdoc.cern.ch/cms/cpt/tdr/ • CERN/LHCC 2006-001 CERN/LHCC 2006-021 • Published submitted to LHCC A. Nikitenko

  10. Physics runs 2008-2009 First , we should “discover” Standard Model

  11. Top with 300 pb-1 • simple selection : Missing ET, 1 lepton, ≥4 jets , NO b-tag (!), cut on hadronic W mass Atlas FullSim Preliminary Top pair events in 300 pb-1 Mreco A. Nikitenko “Discovery” of the Standard Model Discover the ‘Discovered’ to know the Potential for Undiscovered • Drell-Yan (W, Z)production of lepton pairs • best known cross section at LHC NNLO : scale uncert. ~ 1% Dixon, Anastasiou, Melnikov, Petriello • Constrain PDFs, eg. from W+/W- • Luminosity monitor Jet energy scale from Wjet jet, commission b-tagging Understand the Leptons Understand the Jets

  12. First Data • 1 fb-1(100 pb-1)=6 months(few days) at L=1032cm-2sec-1 with 50% data taking efficiency a few 1/fb per experiment at the end of 2008 W,Z events will be used for calibration Top events also will be used to for JES,.. M. Guchait

  13. e-rapidity e+ rapidity CTEQ61 CTEQ61 MRST02 MRST02 ZEUS02 ZEUS02 ds(We)/dy Generated Generated y ds(We)/dy Reconstructed Reconstructed y PDF: W/Z process W±→e±ν rapidity distributions The experimental uncertainty small to Distinguish the PDF sets. PDF errors are sensitive to e rapidity Distributions ATLAS studies shows it is possible to distinguish different PDF if Exp. Uncertainty ~3-5% M. Guchait

  14. HiggZWlogy at LHC, H->ZZ, WW H->ZZ(*)->4l - golden mode of CMS • Background: tt, ZZ, llbb (“Zbb”) • Selections : • lepton isolation in tracker and calo • lepton impact parameter, mm, ee vertex • mass windows MZ(*), MH H->ZZ->ee mm A. Nikitenko

  15. H->ZZ->4l • New elements of analysis: • ZZ background: NLO k factor depends on m4l • background from side bands or from ZZ/Z; (gg->ZZ is added as 20% of LO qq->ZZ, no generator yet) Signal and background at 5 sigma discovery eemm eemm CMS at 5s sign. CMS at 5s sign. A. Nikitenko

  16. Early discovery with H->WW->2l2n ...counting experiment... Discovery reach with H->WW->2l after cuts: - ETmiss > 50 GeV - jet veto in h < 2.4 - 30 <pT l max<55 GeV - pTl min > 25 GeV - 12 < mll < 40 GeV CMS Physics TDR 2006 A. Nikitenko

  17. H  τ (Pτ =+1) gives hard τ-jet from π,ρL, a1L W  τ (Pτ = -1) gives hard τ-jet from ρT , a1T Can be distinguished from X= pπ± / pτ-jet τ-Polarization: => 90% of 1-pr. hadronic decay V = ρ,a1 Exploit τ-Polarization at LHC D.P.Roy

  18. Taus as Discovery tools at LHC D.P.Roy First, full simulation analysis of qqH, H->tt->l+jet SM discovery light h in MSSM Discovery in Standard Model A. Nikitenko

  19. CMS Potential for SM Higgs Boson Discovery A. Nikitenko

  20. CMS reach for MSSM neutral Higgs bosons • pp->bbf (f->h, H, A) – high tanb f->mm , f->tt • pp->A at low tanb • A->Zh , Z->ll (l=e, m) and h->bb A.Nikitenko

  21. pp->bbf, f->mm Discovery reach at low MA, “intensive coupling” and decoupling regimes Possible constraint on tanb by measuring width of A/H->mm

  22. H/A->2t analysis 2006 mtt with e/m+j and j+j modes after selections Selections include single b tagging, thus selecting gg->bbA/H production process A. Nikitenko

  23. Z->tt as benchmark for H->tt mass reconstruction bbZ as benchmark for bbH kinematics Z+2 b-tagged jetsat CMS, 2006 CMS, 2006 Z->tt->m+jet in CMS, 2006: S ~ 1000 ev, B: tt ~ 60 ev., W+j ~ 40ev. , bb ~ 60 ev. for 30 fb-1

  24. MSSM neutral Higgs bosons at LHC CMS prospects for discovery Phys TDR 2006 A. Nikitenko

  25. Selections 2006: ETmiss > 100 GeV ETtjet > 100 GeV t polarization: Rt = p ltr/Et jet > 0.8 Mtop + b tagging veto of 4th jet ETHiggs > 50 GeV A. Nikitenko, D.P.Roy

  26. If SUSY is seen, Can we reconstruct the masses? K. Mazumdar

  27. CMS reach at LHC • The latest simulation studies show: • SM inclusive h->2g could be discovered with < 10fb-1, associated with tt and W (tth, Wh): >= 100 fb-1 at high lumi • almost no change in the discovery potential with H->ZZ->4l and H->WW->2l. First study of Higgs CP properties with H->ZZ->4l • tth, h->bb is lost as discovery channel even with 60 fb-1 • qqh, h->tt “survived” after full simulation ! The biggest discovery reach in MA-tanb • MSSM H+ : gap in MA-tanb at MH+ ~ mt is closed • MSSM H+->tn and H/A->tt : discovery reach is a bit reduced with full simulation, reconstruction and systematics • MSSM f(h,H,A)->mm : possible to constrain tanb with width measurement • first studies on Higgs in 5D RS and little Higgs models

  28. Tracking for Better Jets Olga Kodolova Understanding different contributions to Jet is a delicate balancing act

  29. SM and BSM Scalar mass not protected by any symmetry And the winner is… LHC will tell Or will it? A. Raychaudhuri, B. Mukhopadhyaya, A. Datta …

  30. S. Rindani Study of WW scattering can give information on Electroweak Symmetry Breaking sector and discriminate between different models

  31. Need Reliable estimate of Higgs Cross-Section at LHC Too many terms V. Ravindran Knowledge of Higgs Production Cross-Section Pretty Good NNNLO on the way

  32. Heavy Ions, QGP ….. RV Gavai RK Choudhuri Models that were successful in describing SPS data fail to describe data at RHIC - too much suppression -

  33. RKC Implementing regeneration: much better agreement with the data

  34. R. Gavai

  35. R. Gavai

  36. LHC RHIC Vogt, hep-ph/0205330 Heavy-ion physics at LHC Medium modification at high pT Copious production of high pT particles Large jet cross-section Different melting for members of Y family depending on binding energy Larger cross-section for J/y and Y families J/y Correlations, scattering in medium jets directly identifiable O. Kodolova

  37. At LHC a new regime of heavy ion physics will be reached where hard particle production can dominate over soft events, while the initial gluon densities are much higher than at RHIC, implying stronger partonic energy loss observable in new channels. • CMS is an excellent device for the study of quark-gluon plasma by hard probes: - Quarkonia and heavy quarks - Jets, ''jet quenching'' in various physics channels • CMS will also study global event characteristics: - Centrality, Multiplicity - Correlation and Energy Flow reaching very low pT • CMS is preparing to take advantage of its capabilities - Excellent rapidity and azimuthal coverage, high resolution - Large acceptance, nearly hermetic fine granularity hadronic and electromagnetic calorimetry - Excellent muon and tracking systems - New High Level Trigger algorithms specific for A+A - Zero Degree Calorimeter, CASTOR and TOTEM will be important additions extending to forward physics What CMS can do in Heavy Ion Physics at LHC O. Kodolova

  38. Post LHC Scenarios in High Energy Physics If Liberals are right: Surge of Hep Activity Larger Hep Collaborations If Conservatives are right: We see SM objects Light Higgs Confirmed If none are right: More exotic, but beyond reach Last Hep Community Days of Judgment are getting closer !

  39. Backup Slides

  40. V. Ravindran

  41. Cross sections for MSSM Higgs bosons production at LHC Xt=61/2MS (mhmax scenario), MS=2TeV, mt=178 GeV, mb(mb)=4.9 GeV; NLO QCD corrections for all channels, but ttF, bbF; mR=mF=1/2(MF+2mt) for ttF and ¼(MF+2mb) for bbF. NLO MRST set of PDF

  42. Muon System • Identification: At least 16λ material present up to |η|=2.4 • Trigger: Combination of precise and fast detectors for trigger on single or multi muon events with pT from a few to 100 GeV • Momentum Resolution: Standalone 8-15% at 10 GeV to 20-40% at 1 TeV. Global 1-1.5% at 10 GeV to 6-17% at 1 TeV • Charge Assignment: Correct to 99% confidence up to 7 TeV

  43. CMS Detector A. Gurtu, S. Banerjee, A. Nikitenko

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