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Title: High- pT pi 0 production with respect to the reaction plane in Au + Au collisions at root sNN = 200 GeV

Journal Article · · Physical Review, C (Nuclear Physics)

Measurements of the azimuthal anisotropy of high-p{sub T} 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 article were collected during the 2004 Relativistic Heavy Ion Collider 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} mesons 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 (v{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:
Brookhaven National Lab. (BNL), Upton, NY (United States). Relativistic Heavy Ion Collider (RHIC)
Sponsoring Organization:
USDOE SC OFFICE OF SCIENCE (SC)
DOE Contract Number:
DE-AC02-98CH10886
OSTI ID:
1040237
Report Number(s):
BNL-90690-2009-JA; PRVCAN; R&D Project: PO 003; KB0201021; TRN: US1202362
Journal Information:
Physical Review, C (Nuclear Physics), Vol. 80, Issue 5; ISSN 0556-2813
Country of Publication:
United States
Language:
English