1. CMS / ATLAS production: quarkonia, cross section, correlations Valery P. Andreev University of California, Los Angeles on behalf of the CMS and ATLAS Collaborations 12 th International conference on B-physics at Hadron Machines BEAUTY09, Heidelberg, Germany 7-11 September 2009

2. Outline Introduction LHC: schedule, ATLAS/CMS detectors onia production at LHC –triggers –cross sections –polarization b production at LHC –b tagging –cross sections –high luminosity run (P T reach) –correlations conclusions Valery Andreev, UCLA 2BEAUTY09, 7-11 Sept. 2009

3. Heavy Flavor study prospects in ATLAS and CMS vs luminosity Cross sections for beauty, charm, onia Prompt and indirect J/Ψ, exclusive B decays Onia production study –polarisation, correlations, Υ bb correlations Life time of B hadrons high P T b production cross section B s oscillations CP violation FCNC rare decays (B  μμK, B s  μμ, …) BEAUTY09, 7-11 Sept. 2009Valery Andreev, UCLA 3 − Ο ( 10 pb -1 ) Ο ( 100 pb -1 ) Ο ( 1 fb -1 ) Ο ( 10 fb -1 )

4. BEAUTY09, 7-11 Sept. 2009Valery Andreev, UCLA 4 Heavy Flavour production b production at hadron colliders –Huge cross section –in other SM processes (top, Z, …) –Challenge for perturbative QCD –Tevatron measurements are on top of NLO QCD calculations –New physics searches: b jets as a signal feature (SM Higgs, SUSY decay chains, …) b jets as a background onia production at hadron colliders –prompt quarkonia production not yet understood –Color Singlet Model, Color Octet Mechanism, NRQCD,... –polarisation measurements challenging theory as well A.Grelli, EPS09

5. BEAUTY09, 7-11 Sept. 2009Valery Andreev, UCLA 5 The CMS detector Onion structure: Tracker Calorimeters Muon system Precise e, , , jets, E T Efficient b tagging,  detection General-purpose detector

6. BEAUTY09, 7-11 Sept. 2009Valery Andreev, UCLA 6 Muon detector The ATLAS detector TRT and Si tracker Tile CAL LAr CAL Toroids 2T solenoid General-purpose detector

7. LHC schedule 2009-2010 BEAUTY09, 7-11 Sept. 2009Valery Andreev, UCLA 7 http://lhc-commissioning.web.cern.ch/lhc-commissioning/luminosity/09-10-lumi-estimate.htm

8. Quarkonia production measurement at LHC (CMS) low luminosity (start-up) conditions –Lowest possible trigger thresholds, if any Double-muon trigger with P T > 3 GeV/c, |η| < 2.4 Single muon trigger with threshold P T > 3,5,9 GeV/c – depends on lumi –open-muon trigger at start-up Displaced dimuon vertex trigger –Take advantage of already aligned by cosmics tracker close to ~ 100 pb -1 collision data alignment scenario Expectation for 10 pb -1 –250k J/Ψ –60k b  J/Ψ X –60k Υ BEAUTY09, 7-11 Sept. 2009Valery Andreev, UCLA 8 Helpful in detector calibration and trigger/tracker/muon chambers commissioning

9. Quarkonia production measurement at LHC (ATLAS) Trigger (dimuon) –Topological dimuon trigger – μ6μ4 μ 1 : P T > 6 GeV/c μ 2 : P T > 4 GeV/c μ4μ4 at start-up OR –single muon trigger P T > 6 GeV/c (μ4 at start-up) –dimuon trigger seeded by single muon, extended region of interest off-line: mass and vertex cuts BEAUTY09, 7-11 Sept. 2009Valery Andreev, UCLA 9 μ1μ1 μ2μ2 μ1μ1 no vtx and cτ cut Prompt J/ψ and ϒ production J/ψ with CMS ATLAS ATLAS trigger 2μ3 μ6μ4 mass res.(MeV) 30 54 yield/10pb -1 250k 150k ATLAS, CERN-OPEN-2008-020

10. J/ψ production study (CMS) BEAUTY09, 7-11 Sept. 2009Valery Andreev, UCLA 10 PAS BPH-07-002 Inclusive J/ψ cross section: 1-D fit to mass spectra Prompt vs non-prompt (B  J/ψ X): 2-D fit to mass spectra and pseudo-proper decay length 3 pb -1 Systematics dominated already at start-up Systematics at ~15% level Competitive with Tevatron starting with the first picobarns

11. J/ψ and ϒ production (ATLAS) BEAUTY09, 7-11 Sept. 2009Valery Andreev, UCLA 11 no vtx and cτ cut 10 pb -1 estimate prompt fraction selected by vertexing, cut on pseudo-proper time Polarisation as discriminant between models

12. Quarkonia polarization analysis BEAUTY09, 7-11 Sept. 2009Valery Andreev, UCLA 12 ATLAS CMS Tevatron: no model to describe cross section and polarization at the same time efficiency depends on polarisation α parameter: +1 – transverse polarization - 1 – longitudinal 0 – unpolarized

13. BEAUTY09, 7-11 Sept. 2009Valery Andreev, UCLA 13 B-production / QCD aspects present status of the production phenomenology at hadron colliders –The shape of transverse momentum and angular distributions as well as the azimuthal angular correlations in a reasonable agreement with perturbative QCD –The observed cross-sections are larger than QCD predictions –The agreement between experiment and theory has improved due to the evolution of latter mostly a consequence of improved experimental inputs More precise parton density function, up-to-date  s Improvement on fragmentation effects estimate –The agreement is not complete, to improve the phenomenological description requires new experimental input (LHC) Review on R=σ b /σ NLO, F.Happaher, P.Giromini,F.Ptohos PRD 73, 014026 (2006) experiment is systematically above NLO QCD prediction

14. BEAUTY09, 7-11 Sept. 2009Valery Andreev, UCLA 14 B acceptance ATLAS/CMS –|  | < 2.5/2.4 Tracker/muon detector acceptance –high-P t muon trigger –b-tagged jet trigger LHCb –Forward spectrometer 1.9 <  < 4.9 –much softer p t triggers There is an overlap CMS study: much higher P t can be reached

15. B tagging BEAUTY09, 7-11 Sept. 2009Valery Andreev, UCLA 15 CMS PAS-BTV-07-003 (2008) most performing: Combined Secondary Vertex algorithm (high luminosity run) different misalignment scenarios studied SoftMuon algorithm: efficiency < 20 % (B branching ratio) robust against misalignment

16. BEAUTY09, 7-11 Sept. 2009Valery Andreev, UCLA 16 CMS Analysis: Inclusive b production B production total cross section Differential cross sections d  /dp t’ d  /d  –Selection b-tagged jet semileptonic b-decays into muons –Luminosity: 10 fb -1 CMS Note 2006/120, V.P. Andreev, D.B. Cline, S. Otwinowski The most energetic b tagged jet as the reconstructed B-particle candidate the rate of b jets is a direct measurement of the b production with only small fragmentation systematics

17. BEAUTY09, 7-11 Sept. 2009Valery Andreev, UCLA 17 Event selection Trigger Level-1: High Level Trigger: “single  ”, “muon + b-jet”, p t >14 GeV/c, |  | 19GeV/c, E t jet >50GeV, |  | < 2.4  = 18 %  = 60 %  Off-line selection B-tagged jet: E t > 50 GeV, |  | < 2.4  = 65 % (barrel), 55 % (endcap) Muon associated with B-tagged jet  = 75 %

18. BEAUTY09, 7-11 Sept. 2009Valery Andreev, UCLA 18 B-jet resolution/B-tag efficiency  = 12.9 %  = 5.7 % P t > 170 GeV/c B tag: inclusive secondary vertex in jets

19. BEAUTY09, 7-11 Sept. 2009Valery Andreev, UCLA 19 Fit results Muon P t w.r.t. the closest B jet QCD eventsMC: 230 < P t < 300 GeV/c Nb =5250 (56 % Nc = 2388 (26% Nudsg= 1740(18% --------- 9378 events Fit: Nb =5222  501 Nc = 2050  728 Nudsg =1778  341 --------- 9050 events b c udsg

20. BEAUTY09, 7-11 Sept. 2009Valery Andreev, UCLA 20 b-quark P t reach We can reach 1.5 TeV as the highest measured B hadron P t B hadron –P t > 50 GeV/c –|  | < 2.4 statistical systematic

21. BEAUTY09, 7-11 Sept. 2009Valery Andreev, UCLA 21 B production at LHC, P T reach Extended P t reach CMS analysis summary ~16 M b events to be selected with 10 fb -1 b purity in a range from 70 % to 55 % up to 1.5 TeV B-hadron P t reach

22. Exclusive B production BEAUTY09, 7-11 Sept. 2009Valery Andreev, UCLA 22 CMS PAS-BPH-09-001 (2009) B +  J/ψ K + B 0  J/ψ K *0 10 TeV Differential cross sections can be measured with statistical precision better than 10 % for 10 pb -1 luminosity (early data)

23. BEAUTY09, 7-11 Sept. 2009Valery Andreev, UCLA 23 B production mechanisms at LHC Pair creation (LO) : ~50  b hep-ph/0003142  bb = 465  b ( ~ 500  b ) Gluon splitting (NLO) : ~190  b Flavor excitation (NLO) : ~220  b Both, ATLAS and CMS, will measure bb-correlations  bb as discriminating variable B  J/  X + B    bb = φ J/Ψ - φ μ PYTHIA MC prediction @ LHC b-jet + B    bb = φ b-jet - φ μ b-jet + b-jet  bb = φ b-jet – φ b-jet

24. bb correlations BEAUTY09, 7-11 Sept. 2009Valery Andreev, UCLA 24 _ B  J/  X + B   CMS PAS-BPH-08-004 (2009) bb fraction extracted by simultaneous 3D unbinned maximum LH to J/ψ invariant mass, J/ψ transverse flight length, μ impact parameter Expected total uncertainty between 15 and 25 % for 50 pb -1

25. BEAUTY09, 7-11 Sept. 2009Valery Andreev, UCLA 25 Conclusions data on b production and quarkonium need to be yet reconciled with theory ATLAS and CMS have an intense program for the QCD test in Heavy Flavor production at LHC energies correlations and polarization measurements are foreseen to investigate in detail production mechanisms HF measurements important for New Physics search Eagerly looking forward to the first LHC collision data this year !