QWG Sept 20-22, Jundong Huang Indiana University 1 DØ Quarkonium Production at DØ Jundong Huang Indiana University Quarkonium Workshop FermiLab September 20-22, 2003

QWG Sept 20-22, Jundong Huang Indiana University 2 Outline The Run II DØ Detector J/ ,  (2s) signals B  J/  +X signals observed by DØ  c  J/   signal Quarkonium production at DØ : goals Preliminary J/  cross section vs rapidity Preliminary results of  ( 1S ) differential distributions Conclusions

QWG Sept 20-22, Jundong Huang Indiana University 3 Calorimeters Tracker Muon System Beamline Shielding Electronics protons 20 m antiprotons The Run II DØ Detector

QWG Sept 20-22, Jundong Huang Indiana University 4 Muon Detector Upgrade Muon rapidity coverage to eta of 2.0 Comparing to RunI, shielding reduces backgrounds by x

QWG Sept 20-22, Jundong Huang Indiana University 5 Delivered and Recorded Luminosity Lepton-Photon 2003 B-physics analyses based on integrated luminosity of 114 pb -1 Summer 03 Data Sample

QWG Sept 20-22, Jundong Huang Indiana University 6 Luminosity: 114 pb -1 J/  Signal= 290k events Mass= GeV/c 2 Width = 74 MeV/c 2, Signal J/ ,  (2s) Signal  (2s) = 8222 events Mass= GeV/c 2 Width = 71 MeV/c 2 DZero is reprocessing the data with improved tracking. This will increase the J/  efficiency.

QWG Sept 20-22, Jundong Huang Indiana University 7  c signals  c signals Requirements: M(dimu)-M(J/  ) <0.2GeV p T (  )>1 GeV p T (J/  )<10 GeV Indirect J/  production from higher charmonium states  c1 and  c2 seperated by ~45 MeV The ratio of  c1 and  c2 is a test of different quarkonium production models Luminosity: 114 pb -1

QWG Sept 20-22, Jundong Huang Indiana University 8  conversion vertices

QWG Sept 20-22, Jundong Huang Indiana University 9 Inclusive B  Lifetime Inclusive B  J/  + X Lifetime Measure inclusive B lifetime Separation of prompt and non-prompt J/  production ~18% J/  from B decays

QWG Sept 20-22, Jundong Huang Indiana University 10 B  (1) B  J/  + X Signals (1) B d  J/  K s 0 B d  J/  K* B   J/  K 

QWG Sept 20-22, Jundong Huang Indiana University 11 B  (2) B  J/  + X Signals (2) B s  J/    b  J/  

QWG Sept 20-22, Jundong Huang Indiana University 12 DØ Quarkonium Production at DØ We intend to measure: -J/ ,  (2S) and  (nS) differential cross sections in several rapidity ranges -Charmonium prompt and non-prompt production -Quarkonium direct and indirect production -J/ ,  (2S) and  (nS) polarization

QWG Sept 20-22, Jundong Huang Indiana University 13 ~30% systematic uncertainty 4.8 pb -1 of data Region not measured in Run I Run II J/  production cross section Summer 2002 Results

QWG Sept 20-22, Jundong Huang Indiana University 14 Examples of mass plots p T bins (vertical) : 1-2 GeV; 3-4 GeV; 4-6 GeV; rapidity bins (horizontal): 0.0<|y  |<0.6 (6.2k events) 0.6<|y  |<1.2 (7.6k events) 1.2<|y  |<1.8 (5.6k events) Requirements: p T  >3.0 GeV; |   |<1.8 3 layer muon tracks matched to central track with at least two silicon hits Muon isolation cuts Upsilon(nS) signals Rapidity pTpT

QWG Sept 20-22, Jundong Huang Indiana University 15 Upsilon(1S) fitted signal width fitted signal width in 0.6<|y|<1.2  (1S)

QWG Sept 20-22, Jundong Huang Indiana University 16 Upsilon(1S) differential distribution Normalized differential distribution as a function of  (1S) p T in three rapidity bins. There is little variation in the shape of p T distributions with rapidity.  (1S) DZero Preliminary Results

QWG Sept 20-22, Jundong Huang Indiana University 17 Upsilon(1S) differential distributions Comparison of Normalized differential distribution: DØ Run II |y  |<1.8 CDF Run I |y  |<0.4 DZero Preliminary(|y|<1.8)  (1S)

QWG Sept 20-22, Jundong Huang Indiana University 18 Conclusion Summer 2003 B-physics analyses based on integrated luminosity of 114 pb -1 Over 290k J/  and 20k  (1S) events reconstructed Analyses of J/  and  (1S) differential cross sections in various rapidity ranges are underway  c signals from  conversions established We have started to study the J/ ,  (2s) and  (1S) polarization All data are being reprocessed with better tracking