quarkonium production at dØ
DESCRIPTION
Quarkonium Production at DØ. Jundong Huang Indiana University Quarkonium Workshop FermiLab September 20-22, 2003. Outline. The Run II DØ Detector J/ , (2s) signals B J/ +X signals observed by DØ c J/ signal Quarkonium production at DØ : goals - PowerPoint PPT PresentationTRANSCRIPT
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Quarkonium Production at DØDØ
Jundong Huang Indiana University
Quarkonium WorkshopFermiLab
September 20-22, 2003
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OutlineOutline• 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
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Calorimeters Tracker
Muon System
Beamline Shielding
Electronics
protons
20 m
antiprotons
The Run II DØ DetectorThe Run II DØ Detector
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Muon Detector UpgradeMuon Detector Upgrade
• Muon rapidity coverage to eta of 2.0
• Comparing to RunI, shielding reduces backgrounds by 50-100x
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Delivered and Recorded Delivered and Recorded LuminosityLuminosity
Lepton-Photon 2003
B-physics analyses based on integrated luminosity of 114 pb-1
Summer 03 Data Sample
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Luminosity: 114 pb -1
J/ Signal= 290k eventsMass= 3.072 GeV/c2
Width = 74 MeV/c2
J/, , (2s) Signal Signal
(2s) = 8222 eventsMass= 3.668 GeV/c2
Width = 71 MeV/c2
DZero is reprocessing the data with improved tracking.This will increase the J/ efficiency.
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c c signals signals
Requirements:
• M(dimu)-M(J/) <0.2GeV
• pT()>1 GeV• pT(J/)<10 GeV
Indirect J/ productionfrom higher charmoniumstates
c1 and c2 seperated by~45 MeV
The ratio of c1 and c2 is atest of different
quarkoniumproduction models
Luminosity: 114 pb -1
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conversion verticesconversion vertices
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Inclusive Inclusive B B J/ + X Lifetime Lifetime
• Measure inclusive B lifetime
• Separation of prompt and non-prompt J/ production
• ~18% J/ from B decays
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B B J/ + X Signals (1) (1)
Bd J/ Ks0Bd J/ K* B J/ K
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B B J/ + X Signals (2)(2)
Bs J/ b J/
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Quarkonium Production at DØDØ
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
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~30% systematic uncertainty
4.8 pb-1 of data
Region not measured in Run I
Run II J/ production cross section
Summer 2002 Results
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Examples of mass plots pT 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:• pT
>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 Upsilon(nS) signals Rapidity
pT
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Upsilon(1S) fitted signal widthUpsilon(1S) fitted signal width
fitted signal width in 0.6<|y|<1.2
(1S)
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Upsilon(1S) differential Upsilon(1S) differential distributiondistribution
Normalized differentialdistribution as afunction of (1S)
pT in three
rapidity bins.
There is littlevariation in the
shape of pT
distributions withrapidity.
(1S)
(1S)
(1S)
DZero Preliminary Results
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Upsilon(1S) differential Upsilon(1S) differential distributionsdistributions
Comparison ofNormalizeddifferential distribution:• DØ Run II |y|
<1.8 • CDF Run I |y|
<0.4 DZero Preliminary(|y|<1.8)
(1S)
(1S)
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ConclusionConclusion
• 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