Parton energy loss in heavy-ion collisions via direct-photon and charged-particle azimuthal correlations

Abelev, B. I. and Planinić, Mirko and Poljak, Nikola and Zuo, J. X. (STAR Collaboration) (2010) Parton energy loss in heavy-ion collisions via direct-photon and charged-particle azimuthal correlations. Physical Review C, 82 (3). pp. 34909-8. ISSN 0556-2813

[img]
Preview
PDF - Published Version
Language: English

Download (508kB) | Preview

Abstract

Charged-particle spectra associated with direct photon (γdir) and π0 are measured in p+p and Au+Au collisions at center-of-mass energy √sNN=200 GeV with the STAR detector at the Relativistic Heavy Ion Collider. A shower-shape analysis is used to partially discriminate between γdir and π0. Assuming no associated charged particles in the γdir direction (near side) and small contribution from fragmentation photons (γfrag), the associated charged-particle yields opposite to γdir (away side) are extracted. In central Au+Au collisions, the charged-particle yields at midrapidity (|η|<1) and high transverse momentum (3<pTassoc<16 GeV/c) associated with γdir and π0 (|η|<0.9, 8<pTtrig<16 GeV/c) are suppressed by a factor of 3–5 compared with p+p collisions. The observed suppression of the associated charged particles is similar for γdir and π0 and independent of the γdir energy within uncertainties. These measurements indicate that, in the kinematic range covered and within our current experimental uncertainties, the parton energy loss shows no sensitivity to the parton initial energy, path length, or color charge.

Item Type: Article
Keywords: p p, interaction gold charged particle, yield parton, energy loss photon, direct production pi0, hadroproduction charged particle, associated production angular correlation, (charged particle photon) angular correlation, (charged particle pi0) transverse momentum, dependence heavy ion, scattering Brookhaven RHIC Coll parton, path length STAR 200 GeV-cms/nucleon
Date: September 2010
Subjects: NATURAL SCIENCES > Physics
Additional Information: Copyright (2010) by the American Physical Society.
Divisions: Faculty of Science > Department of Physics
Project code: 119-0982887-1006
Publisher: American Physical Society
Depositing User: Gordana Stubičan Ladešić
Date Deposited: 05 Jun 2014 12:49
Last Modified: 24 Feb 2016 15:28
URI: http://digre.pmf.unizg.hr/id/eprint/2270

Actions (login required)

View Item View Item