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Xiaorong Wang, Heavy Flavor Workshop at UIC, June, 2012 11
Heavy Flavor and Spin Program
at
Xiaorong WangNew Mexico State University
Heavy Flavor workshop at UIC June 17-18, 2012
Xiaorong Wang, Heavy Flavor Workshop at UIC, June, 2012 2
Heavy Flavor measurement at PHENIX Gluon Spin in the Proton (ΔG) Transverse Spin Physics Flavor Separated Sea Quark Spin
• Drell-Yan ALL (heavy flavor related) Future Forward Physics Program at PHENIX
Xiaorong Wang, Heavy Flavor Workshop at UIC, June, 2012
2 central arms: electrons
• charmonium J/, ’ ee• open charm, beauty (D,Be)
2 muon arms: muons
• “onium” J/, ’, • open charm, beauty
(D,B)
Heavy Flavor Measurement at PHENIX
e+(e-)
+(-)
GeVpT 5.0,35.0||
GeVpT 5.0,4.2||2.1
3
Xiaorong Wang, Heavy Flavor Workshop at UIC, June, 2012 4
Silicon Vertex Detector at PHENIX
VTX (2011) and FVTX (2012)• Displaced vertex tagging of D, B decay products• Direct D reconstruction, BJ/• ’, upsilons
Silicon Tracker
D
Xiaorong Wang, Heavy Flavor Workshop at UIC, June, 2012
Two Arms, Four tracking stations with full azimuthal coverage• 75 m pitch strips in radial direction, 3.75° staggered phi strips• Radiation length < 2.4%/wedge to minimize multiple scattering• Outer Support and Cooling outside active area• Kapton cable plant primarily outside active area
Xiaorong Wang, Heavy Flavor Workshop at UIC, June, 2012 6
Summary of FVTX Status in 2012 Over 90% of Detector is operational and Detector performance design specifications have been met. Software are tuning with real data.
Track fitting with MuTr Alignment
New trigger for open heavy flavor physics FVTX simulation and data analysis
9
FVTX Commissioning and Current Status
Radiographs from reconstructed tracks pp510U+U 200 GeV event display
Xiaorong Wang, Heavy Flavor Workshop at UIC, June, 2012 7
Heavy Flavor SG3 trigger Development
North SG3 &&MuID South SG3 &&MuID
CuAu CuAu
SG1 Trigger: p > 15GeV for W analysisSG3 Trigger: p > 5 GeV for heavy flavorAdd 3-5 more rejection power on top of current MuID trigger
Xiaorong Wang, Heavy Flavor Workshop at UIC, June, 2012
The challenge: backgrounds ( ->μ and K-> μ) overwhelm the signal. Flying distance and decay angle are different. Get DCA components in r (higher resolution) and phi (moderate resolution). Significant improvement in angular resolution of track leading to dimuons mass resolution Track isolation cut will suppress hadrons from jet for W measurement Joint tracking with MuTr. Track χ2 cut will discriminate muon from hadron background.
8
Xiaorong Wang, Heavy Flavor Workshop at UIC, June, 2012 10
Heavy Flavor measurement at PHENIX Gluon Spin in the Proton (ΔG) Transverse Spin Physics Flavor Separated Sea Quark Spin
• Drell-Yan ALL (Heavy Flavor Related) Future Forward Physics Program at PHENIX
Xiaorong Wang, Heavy Flavor Workshop at UIC, June, 2012 11
DIS pQCD e+e-?
Study difference in particle production rates for same-helicity vs. opposite-
helicity proton collisions
-- Parton distribution functions -- Partonic hard scattering rates -- Fragmentation functions
Probing the Helicity Structure of the Nucleon
W. Vogelsang
NLO sub-process in π production
LNLN
LNLN
PPALL //
//
||
1
21
)...()ˆ(ˆ)()()(0
210 zDsxgxqXpp q
qgqg
Xiaorong Wang, Heavy Flavor Workshop at UIC, June, 2012 12
Major impact of program Strong indication for a small gluon polarization! Next steps: Map x-dependence and extension of x-coverage
PRL 101, (2008)072001 DSSV 08
Impact of RHIC-Spin Program on Δg
best fit has a zero-crossing at x ≈ 0.1
S. Wolin DIS2012
Xiaorong Wang, Heavy Flavor Workshop at UIC, June, 2012 13
Heavy-flavor production is leading-order gluon interactions
Heavy Flavor ALL at PHENIX
QQggLLLL a
xg
xg
xg
xgA
)(
)(
)(
)(
2
2
1
1
W. Vogelsang
NLO sub-process in π production
QQqgLLLL a
xg
xg
xq
xqA
)(
)(
)(
)(
2
2
1
1
Xiaorong Wang, Heavy Flavor Workshop at UIC, June, 2012 16
Heavy Flavor ALL with FVTX
Heavy flavor with FVTX will allow us access small x.
Xiaorong Wang, Heavy Flavor Workshop at UIC, June, 2012 17
Heavy Flavor measurement at PHENIX Gluon Spin in the Proton (ΔG) Transverse Spin Physics Flavor Separated Sea Quark Spin
• Drell-Yan ALL (Heavy Flavor Related) Future Forward Physics Program at PHENIX
Xiaorong Wang, Heavy Flavor Workshop at UIC, June, 2012 18
Theoretical Models of TSSA (I) Transverse momentum dependent (TMD) function approach
Assuming TMD factorization….
TMD factorization is not valid for process involving more than two hadrons. T.Rogers, P Mulders, PRD81, 094006(2010)
-- Sivers mechanismD. Sivers, PR D41 (1990) 83; D43 (1991) 261
-- Collins mechanismJohn Collins, Nucl Phys B396 (1993) 161
),()( 221
kzHxqAN )(),( 2 zDkxfA hq
qTN
18
Xiaorong Wang, Heavy Flavor Workshop at UIC, June, 201219
Collinear factorization approach
Twist-3 factorization works at Q >>ΛQCD,
-- Twist-3 quark-gluon correlation function TqF
-- Two independent tri-gluon correlation functions TG( f ) and TG
( d )
TMDs and Collinear Twist-3 Functions
In the overlap region both approaches give the same physics (Drell-Yan)
Ji, Qiu, Vogelsang and Yuan
PRL 97, 082002 (2006)PRL 97, 082002 (2006)PRL 97, 082002 (2006)PRL 97, 082002 (2006)Collinear
19
Xiaorong Wang, Heavy Flavor Workshop at UIC, June, 2012 20
Sensitive to gluon Sivers function (if it is well defined) * heavy flavor production dominated by gluon gluon fusion at RHIC * gluon has zero transversity
Sensitive to tri-gluon correlation functions
Also sensitive to J/ψ production mechanisms
Gluon Sivers function – Heavy Flavor AN
Xiaorong Wang, Heavy Flavor Workshop at UIC, June, 2012
Anselmino et al, PRD 70, 074025 (2004)
Gluon Sivers=0
Gluon Sivers=Max
Calculations for D mesons
21
AN measured for muons from D decay
Not favor maximum gluon silvers.
Open Charm AN
Measurement for -
H Liu, X Wang and M Liu
V. Dharmawardane, S. Dairaku
Xiaorong Wang, Heavy Flavor Workshop at UIC, June, 2012 22
Kang, Qiu, Yuan, Vogelsang, Phys. Rev. D 78,114013(2008)
BUP12, PHENIX
Xiaorong Wang, Heavy Flavor Workshop at UIC, June, 2012 23
Heavy Flavor measurement at PHENIX Gluon Spin in the Proton (ΔG) Transverse Spin Physics Flavor Separated Sea Quark Spin
• Drell-Yan ALL (Heavy Flavor Related) Future Forward Physics Program at PHENIX
Xiaorong Wang, Heavy Flavor Workshop at UIC, June, 2012 24
Drell-Yan simulations with FVTX
Z. You, X. Wang
Dominate background for4 < mass 10 GeV is b-bbar
Full PYTHIA+PISA simulations for bbar and Drell-Yan with FVTX
Study background rejection with FVTX In Drell-Yan process
Xiaorong Wang, Heavy Flavor Workshop at UIC, June, 2012 25
BUP 12, K. Lee, X. Jiangarxive:1108.4974 (Lu, Ma, Zhu)
)(
)(
)(
)(
2
2
1
1
xu
xu
xu
xu
Sea Quark Spin TMD Functions
Xiaorong Wang, Heavy Flavor Workshop at UIC, June, 2012 26
Heavy Flavor measurement at PHENIX Gluon Spin in the Proton (ΔG) Transverse Spin Physics Flavor Separated Sea Quark Spin
• Drell-Yan ALL (Heavy Flavor Related) Future Forward Physics Program at PHENIX
Xiaorong Wang, Heavy Flavor Workshop at UIC, June, 2012
MuID
RICH
HCalEMCal
Tracker
EMcal
Hcal
2T Magnet
*Not to scale
27
Xiaorong Wang, Heavy Flavor Workshop at UIC, June, 2012
Measurements:• Jets Energy (Sivers, CNM)• Lepton ID (DY, heavy flavor)• , K ID (Collins)• Charge ID (DY, heavy flavor,
pion and kaon asyms)• Momentum
Detector needs:• Calorimtery• Calorimetry, preshower• RICH• Tracker
• Barrel Magnetic, additional(?)
28
K. Boyle
Xiaorong Wang, Heavy Flavor Workshop at UIC, June, 2012 29
Testing QCD: Drell-Yan AN
DIS: attractive Drell-Yan: repulsive
0.1 0.2 0.3 x
Siv
ers
Am
plitu
de
0
HERMES Sivers Results
M. DiefenthalerarXiv:0706.2242
Z. Kang and J. Qiu. Phys. Rev., D81:054020, 2010
Estimated DY AN from global Sivers fit
Xiaorong Wang, Heavy Flavor Workshop at UIC, June, 2012
Heavy flavor is unique channel to understand gluon polarization and gluon Sivers.
PHENIX has measured single electron longitudinal double spin asymmetry to understand ΔG.
PHENIX has measured heavy flavor transverse single spin asymmetry to understand gluon Sivers.
Newly installed FVTX detector has successfully commissioned into PHENIX data taking. New heavy flavor trigger (SG3) is implemented. Good efficiency and rejection achieved low p > 5 GeV single muons.
Heavy flavor spin physics are coming soon.
30
Xiaorong Wang, Heavy Flavor Workshop at UIC, June, 2012 32
Sensitive to gluon Sivers function (if it is well defined) * heavy flavor production dominated by gluon gluon fusion at RHIC
* gluon has zero transversity
Sensitive to tri-gluon correlation functions
Also sensitive to J/ψ production mechanisms
Gluon Sivers function – Heavy Flavor AN
One color-singlet diagramOne color-singlet diagram— no cancellation,
Two color-octet diagramsTwo color-octet diagrams— cancellation no asymmetry
F Yuan, PRD78, 014024(2008)
Xiaorong Wang, Heavy Flavor Workshop at UIC, June, 2012
Gluon Fusion dominates at LO
PYTHIA:
Gluon polarization and ALL
Gluon Sivers function and AN
- eliminate Collions effect
33
(gg QQ ) : (qq QQ )
QQggLLLL a
xg
xg
xg
xgA
)(
)(
)(
)(
2
2
1
1
Xiaorong Wang, Heavy Flavor Workshop at UIC, June, 201234
October 24, 2008
DNP2008, Xiaorong Wang
34
• very different from Light hadrons Carry most of initial quark’s energy,
pi, K, D, B..
EB ~ 80%Eb jet
From PDG
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