Xiangwei Meng Institute of High Energy Physics, CAS, Beijing First Workshop of the CMS Quarkonium Task Force Sep. 12-13, 2009 -- SUMMARY Xiangwei Meng Institute of High Energy Physics, CAS, Beijing Sep. 25 , 2009 2009-08-28 CMS B-physics Group Meeting 08,28,2008

CMS B-physics Group Meeting 08,28,2008 Contents 2 days 20 reports ~30 persons Techniques: CDF’s experience* The CMS trigger strategy and quarkonium physics From T0 to your desktop: the CMS data flow quality criteria for the global and tracker muons* Onia event yields vs. luminosity* Fitting functions for the dimuon mass peaks* Quarkonia models and event generation; bridges with theory …….. Physics From the J/psi to the b harond pt x-section chi_c and chi_b production Upsilon->mu mu Upsilon -> e+e- J/Psi polarization/Upsilon polarization tutorial: luminosity information in the data run the general tag and probe code 2009-08-28 CMS B-physics Group Meeting 08,28,2008

Quarkonium Physics at the Tevatron James Russ Carnegie Mellon University theoretical models to try to match vector meson data from Tevatron and HERA cross section problem  CSM  NRQCD polarization problems with NRQCD  multi-gluon models recent considerations: questions about kT factorization approach, Q fragmentation effects at Tevatron Experimental results: J/  and (2S) cross section and polarization from CDF (1S) and (2S) polarization from D0 brand new results on (1S) polarization from CDF CDF work on new charmonia X(3872) and Y(4140) J/ Analysis to Handle b-Decay Events Two approaches discriminate based on muon miss distance at primary vertex to separate prompt/decay make joint mass-lifetime fit to identify prompt/decay CDF has used each to good avail miss distance analysis is faster joint fit gives best yield estimate for cross section 2009-08-28 CMS B-physics Group Meeting 08,28,2008

X(3872) & another New State – Y(4140) Measure JP at a hadron machine? Yes! pp mass distribution sensitive to orbital angular momentum in decay and hence to parent’s spin-parity Top: fit to expected shape for (2S)  (1S)pp (validate) Bottom: fit to L=0 and L=1 for X(3872)  (1S)pp The X(3872) tries to decay to J/r … but it’s too light. Belle observes another threshold J/V state in B decays: Y(3930)  J/ w CDF used its huge B  J/ X sample to look for a narrow J/ f state near threshold No good theory for these objects, but interesting experimental pattern. 2009-08-28 CMS B-physics Group Meeting 08,28,2008

Glob & Trk Muon selection: low pT David Lopes Pegna (Princeton University) Mario Peliccioni (INFN & University of Torino) need any cut to clean up the global muons? Yes! Main background sources from muons from kaon/pion decays (decay-in-flight) and Kaons/pions that reach the muon system (punch-through) the global muon algorithm is not extremely efficient at low pT Tracker muons help to recover the low pT part of the muon spectrum But higher fake rate from punch-through and DIF Access Chi2/NDF(<10), Nhits(>12) from inner(global) track associated to tracker(global) reco::muon Additional variables are provided in the external function (in 3_X) bool muon::isGoodMuon( const reco::Muon& muon, muon::SelectionType type ) Trk Muons: Summary of cuts 22X(31X) Arbitration TM2DCompatibilityLoose OneStationTight μ χ2 silicon fit < 1.9 μ inner hits > 11(12) 2009-08-28 CMS B-physics Group Meeting 08,28,2008

Fitting functions for the dimuon mass peaks Sara Bolognesi, CERN Fitting functions for the dimuon mass peaks a look to the scale and resolution behavior In the present analyses usually each peak is fit with 2 gaussians(+ background shape linear or exponential) because: bias in the muon scale can shift the mass peak: if bias depends on muon η, pT →different shift peak in different kinematic regions 􀂃resolution on the muon pT(→width of dimuon mass peak) changesas a function of muon ηand pT tracker geometry material budget 2009-08-28 CMS B-physics Group Meeting 08,28,2008

Onia event yields vs. luminosity Zongchang Yang1, Roberto Covarelli2, Fabrizio Palla3 1) University of Tennessee, 2) CERN, 3) INFN Pisa Onia event yields vs. luminosity Summer09 FDMC@10 TeV MC samples Nevts(M) X-sec. (mb) Int. Lumi(pb-1) prompt J/y->m+m- 11.4 0.262 9.9 (0.809) B->J/y->m+m- 10.8 51.6 40 Upsilon(1S)->m+m- 1.0 5.7E-3 55 (0.707) Pp->m+X 10.1 51.6 0.075 (0.939) ~5 pb-1 data are collected before the menu changes Total ~50 pb-1 data of the 7 TeVcollisions First cross section measurement at 5 pb-1integral luminosity –J/psi yields: 0.3 M (global+global), 0.25 M (global+tracker), 0.55 M (global+calo) –J/psi yeilduncertainties: 0.002, 0.006, 0.009 –Upsilon yields: 16 K, 6 K, 6K –Upsilon yeilduncertainties: 0.02, 0.08, 0.7 Lower-purity (tracker and calo) muons: –can be useful for J/ywith single muontrigger before the menu changes –do not improve the signal in double muontriggers HLT_DoubleMu0 is a good choice after menu changes 2009-08-28 CMS B-physics Group Meeting 08,28,2008

Skimming for the Onia studies， 1E31 trig path & new Gen by EvtGen Skimming should always keep all the useful information for the analysis. –Filter on two muons with invariant mass cut (>2 GeV/c2) –Additional cuts on muon qualities: global, tracker and calomuons –Reduce the event size to 150 KB/evt –A reasonable total data size 2009-08-28 CMS B-physics Group Meeting 08,28,2008