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The physics dream

zzzzzzzz …. The physics dream. Three cases usually considered for illustration: A ~ 1 TeV new resonance X  ll 100 pb -1 new forces ? new dimensions ? Supersymmetry (~ 1 TeV ) ~ 1 fb -1 dark matter ?

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The physics dream

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  1. zzzzzzzz …. The physics dream

  2. Three cases usually considered for illustration: • A ~ 1 TeV new resonance X  ll 100 pb-1 new forces ? new dimensions ? • Supersymmetry (~ 1 TeV ) ~ 1 fb-1 dark matter ? • Light Higgs boson (115 Gev) ~ 5 fb-1 origin of mass The dream in one plot ….. Time scale is now optimistic in the light of the recent events …

  3. An “easy case” : Z’  e+e-, mass ~ 1 TeV From CSC Exotics Chapter • Large enough signal for discovery • with 100 pb-1 up to m > 1 TeV •  perhaps sometime in 2009 ? • Signal is (narrow) mass peak above • small and smooth SM background • Does not require ultimate EM calorimeter performance Is this a new force or new dimensions ? From angular distribution of leptons can disentangle Z’ (spin=1) from G (spin=2). Requires more data (~ 100 fb-1)

  4. If it is at the TeV scale, it should be found “quickly” …. thanks to: • large (strong) cross-section for • spectacular signatures (many jets, leptons, missing ET) For expect 1 evt/day at L=1031 LHC reach for gluino mass Ldt Discovery of well understood data (95% C.L. exclusion) 0.1-1 fb-1 (2009-2010) ~1.1 TeV (1.5 TeV) 1 fb-1(2010) ~1.7 TeV (2.2 TeV) 300 fb-1 (ultimate) up to ~ 3 TeV Jets + ETmiss 100 pb-1 100 10 1 Supersymmetry From CSC SUSY Chapter Hints up to m~1 TeV with only 100 pb-1, but understanding backgrounds requires ~1 fb-1 Planning for future facilities would benefit a lot from quick determination of scale of New Physics. With ~ 1 fb-1 LHC could tell if “standard” SUSY accessible to s 1 TeV ILC.

  5. Cone4TowerJet Backgrounds of fake missing ET from calorimeter noise and cosmics events being studied with cosmics data M7 data pT=√(∑px2+∑py2) (all EM for cells with |E|>2σ noise) EM calorimeter noise (from 2482 random triggers) is as expected Comparison of cosmics data to simulation (normalized to same number of seconds) ETmiss > 100 GeV: Data : 493 ± 22 MC : 565 ± 64 ~ 0.05 Hz S.Asai, Y.Kataoka

  6. Cosmics simulation: 163.5 GeV From J3: 60.5 GeV Missing ET: 174.3 GeV From J3: 78.6 GeV H.Okawa Cosmics data M8 run 77585 Criteria to reject cosmics being tested with data S.Asai, Y.Kataoka

  7. H   qqH  qq 9000 6000  H  3000 A more difficult case (more data needed):a light Higgs 30 fb-1 5 fb-1: S=150, B=5000 5 fb-1: S=3, B<1 Combining ATLAS and CMS: 0.2-1 fb-1 of good data for 95% C.L. exclusion 0.5-5 fb-1 of good data for 5 discovery depending on the Higgs mass range Final word about Higgs mechanism by 2011 ? H  ZZ*  4l • mH < 130 GeV: most difficult region: need to • combine many channels with small S or S/B • mH > 130 GeV: discovery easier with • H  4l (narrow mass peak, small B) • H  WW  ll (dominant for 160-185 GeV) • is a counting experiment (no mass peak) 5 fb-1: S=10, B<1 From CSC Higgs Chapter

  8. D0 x 2 LEP exclusion Summer 2008 3 fb-1 Excluded at 95% C.L. in Summer 2008 95% C.L exclusion 3 5 Tevatron 2009 (5.5 fb-1) < 118, 146-185 156-170 LHC 2009 (300 good pb-1 ?) 138-520 155-170 Tevatron 2010 (6.8 fb-1) if approved < 124, 140-190 154-175 LHC 2010 (1 good fb-1 ?) full range > 125 140-500 LHC vs Tevatron Today: 5 fb-1 delivered, 4 fb-1 recorded • The Higgs is not at 170 GeV … phew … • Very sophisticated analyses developed, sensitivity is increasing • Soon they could exclude/probe the region 156-170 GeV

  9. 9 GeV pion (data) SCT Pix TRT We have been and are preparing ourselves to be fast to produce physics results Pion momentum resolution from 2004 combined test beam using Pixels+SCT 2004 combined test-beam: full vertical slice of ATLAS (from Pixels to Muon chambers) tested with beams Achieved alignment precision of Pixels and SCT: 10-25 m No TRT B=1.4 T From ATLAS Detector paper Muon Spectrometer alignment with cosmics data Aim at ~ 30 m with cosmics data collected before shut-down I.Potrap

  10. We do not wish to encourage big experimental searches for the Higgs boson, but we do feel that people performing experiments vulnerable to the Higgs boson should know how it may turn up. How did our views change with time ? Ellis, Gaillard, Nanopoulos Nucl. Phys. B106, 292 (1976) They were obviously right. At that time the W and Z bosons had not been observed yet

  11. Other examples : from the ECFA-CERN Workshop on the “Large Hadron Collider in the LEP tunnel”, held in Lausanne in 1984 “At a hadron collider operating at centre of mass energies of several TeV, muons will be the only leptons which can be detected over a large momentum range.” “Calorimeter coverage for 3  ||  5 is not essential for luminosity > 1033 cm-2 s-1 “ “The raw inelastic collision rate at a luminosity of 3 x 1032 cm-2 s-1 is 3 x 107 per second. To keep the time spent on offline analysis down to a reasonable level, only one of these collisions should be recorded. LVL1 output rate < 105 Hz, LVL2 output rate: 200-1000 Hz, LVL3 output rate: 1 Hz” HOPEFULLY NOT ! “We strongly favour machine designs with an average  1 collision per bunch crossing. Triggering on complicated signatures (necessary for the predicted physics) does not seem feasible in a multi-event environment.” “To provide data information to any external laboratory, disks can be copied and shipped. For bulk analysis, the best scheme would be to connect private workstations to the online computer (“supervisor”) and from there use the (control-room) multi-processor stacks and database.” “Hopefully if MH < 2 MW the H0 meson will be discovered before the LHC comes into operation”

  12. ATLAS mini-workshop on Luminosity and Forward Detectors, 7 February 2000 Colleague # 1 (X.Y.) wrote on his last slide: “ … forward detectors could allow us to discover, IMHO, exotics states, and even perhaps Centauro events” Summary of ATLAS mini-workshop on Luminosity and Forward Detectors, 8 February 2000 Colleague # 2 (W.Z.): “… we could discover many things, exotics states, Centauro events and, as X.Y. said yesterday, even these new IMHO particles (although I am not sure I understood what they are)” What about surprises ? We could discover the famous IMHO particles …

  13. Acknowledgments C.Guyot, F.Ledroit, C.Marcelloni, H.Okawa, G.Polesello, P.Schacht, S.Tapprogge

  14. SPARES

  15. 100 pb-1 With first data …. 1 day at 1031 1 minute at 1031 50 days at 1031 100 days at 1031 20-30 pb-1 enough To observe a signal We are on business

  16. Is it a Z’ or a Randall-Sundrum Graviton ? Look at e± angular distributions to disentangle G (s=2) from Z’ (S=1) Need more integrated luminosity … ATLAS, 100 fb-1, mG=1.5 TeV “data”, spin 2 spin 1 Allanach et al., JHEP 0009 (2000) 019

  17. 10 1 Events / 0.5 GeV 10-1 mH (GeV)

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