PHENIX First Measurement of the J/psi Elliptic Flow Parameter upsilon₂ in Au+Au Collisions at sqrt S_NN = 200 GeV

Conference · Tue Jan 01 04:00:00 EST 2008

OSTI ID:946122

Silvestre, Catherine ^[1]; Cianciolo, Vince ^[2]; Awes, Terry C ^[2]; Efremenko, Yuri V ^[2]; Enokizono, Akitomo ^[3]; Hornback, Donald ^[4]; Read, Jr, Kenneth F ^[2]; Silvermyr, David O ^[2]; Sorensen, Soren P ^[4]; Stankus, Paul W ^[2]; Young, Glenn R ^[2]

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1. CEA, Saclay, France
2. ORNL
3. Lawrence Livermore National Laboratory (LLNL)
4. University of Tennessee, Knoxville (UTK)

Recent results indicate that the J/{psi} suppression pattern differs with rapidity showing a larger suppression at forward rapidity. J/{psi} suppression mechanisms based on energy density (such as color screening, interaction with co-movers, etc.) predict the opposite trend. On the other hand, it is expected that more c{bar c} pairs should be available to form quarkonia at mid-rapidity via recombination. Some models provide a way to differentiate J/{psi} production from initially produced c{bar c} pairs and final state recombination of uncorrelated pairs, via the rapidity and transverse momentum dependence of the elliptic flow ({upsilon}{sub 2}). During 2007 data taking at RHIC, a large sample of Au+Au collisions at {radical}s{sub NN} = 200 GeV was collected. The statistics has been increased compared to previous 2004 data set, thus allowing a more precise measurement of the J/{psi} production at both mid and forward rapidity. Furthermore, the PHENIX experiment benefited from the addition of a new detector, which improves the reaction plane resolution and allows us to measure the J/{psi} {upsilon}{sub 2}. Comparing this measurement to the positive D-mesons {upsilon}{sub 2} (through non-photonic electron decays) will help constraining the J/{psi} production mechanisms and getting a more precise picture of the proportion of J/{psi} coming from direct production or charm quark coalescence. Details on how the J/{psi} {upsilon}{sub 2} is measured at mid-rapidity rapidities are presented. The J/{psi} {upsilon}{sub 2} as a function of transverse momentum are compared to existing models.

• Research Organization: Oak Ridge National Laboratory (ORNL)
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 946122
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
COALESCENCE
COLOR
D MESONS
ELECTRONS
ENERGY DENSITY
PARTICLE RAPIDITY
PRODUCTION
QUARKS
RECOMBINATION
RESOLUTION
STATISTICS
TRANSVERSE MOMENTUM