High-pT pi^zero Production with Respect to the Reaction Plane in Au+Au Collisions at s_NN) = 200 GeV

Journal Article · Thu Jan 01 00:00:00 EST 2009 · Physical Review C

OSTI ID:967986

Adare, A. ^[1]; Awes, Terry C ^[2]; Cianciolo, Vince ^[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. University of Colorado, Boulder
2. ORNL
3. Oak Ridge National Laboratory (ORNL)
4. University of Tennessee, Knoxville (UTK)

Measurements of the azimuthal anisotropy of high-pT neutral pion ({pi}{sup 0}) production in Au+Au collisions at {radical}s{sub NN} = 200 GeV by the PHENIX experiment are presented. The data included in this paper were collected during the 2004 RHIC running period and represent approximately an order of magnitude increase in the number of analyzed events relative to previously published results. Azimuthal angle distributions of {pi}{sup 0}s detected in the PHENIX electromagnetic calorimeters are measured relative to the reaction plane determined event-by-event using the forward and backward beam-beam counters. Amplitudes of the second Fourier component ({nu}{sub 2}) of the angular distributions are presented as a function of {pi}{sup 0} transverse momentum (p{sub T}) for different bins in collision centrality. Measured reaction plane dependent {pi}{sup 0} yields are used to determine the azimuthal dependence of the {pi}{sup 0} suppression as a function of p{sub T}, R{sub AA}({Delta}{phi}, p{sub T}). A jet-quenching motivated geometric analysis is presented that attempts to simultaneously describe the centrality dependence and reaction plane angle dependence of the {pi}{sup 0} suppression in terms of the path lengths of hypothetical parent partons in the medium. This set of results allows for a detailed examination of the influence of geometry in the collision region, and of the interplay between collective flow and jet-quenching effects along the azimuthal axis.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 967986
• Journal Information: Physical Review C, Vol. 80, Issue 5
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
AMPLITUDES
ANGULAR DISTRIBUTION
ANISOTROPY
CALORIMETERS
GEOMETRY
PIONS
PRODUCTION
TRANSVERSE MOMENTUM