The viscosity to entropy density ratio from PHENIX data on single electron production

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

OSTI ID:946116

Averbeck, Ralf ^[1]; Awes, Terry C ^[2]; Cianciolo, Vince ^[2]; Efremenko, Yuri V ^[2]; Enokizono, Akitomo ^[3]; 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. Stony Brook University (SUNY)
2. ORNL
3. Lawrence Livermore National Laboratory (LLNL)
4. University of Tennessee, Knoxville (UTK)

The PHENIX experiment has measured electrons from the decay of hadrons carrying heavy flavor (charm or bottom quarks) in p + p and Au + Au collisions at {radical}s{sub NN} = 200 GeV at the Relativistic Heavy Ion Collider (RHIC). The strong damping of heavy-flavor motion through the medium is reflected in a substantial suppression at high p{sub T} and a large azimuthal anisotropy {upsilon}{sub 2} of such electrons in Au + Au collisions at RHIC. By requiring a simultaneous description of the nuclear modification factor R{sub AA}(p{sub T}) and the azimuthal anisotropy {upsilon}{sub 2}(p{sub T}) in transport models, the viscosity to entropy density ratio of the medium can be estimated as {eta}/s {approx} (1.3-2)(1/4{pi}), which is close to the conjectured lower quantum bound and, therefore, near a perfect fluid.

• Research Organization: Oak Ridge National Laboratory (ORNL)
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 946116
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
74 ATOMIC AND MOLECULAR PHYSICS
ANISOTROPY
DAMPING
DECAY
ELECTRONS
ENTROPY
HADRONS
HEAVY IONS
MODIFICATIONS
PRODUCTION
QUARKS
TRANSPORT
VISCOSITY