Elliptic flow of identified hadrons in Au+Au collisions at √sNN=7.7–62.4 GeV

Adamczyk, L. and Planinić, Mirko and Poljak, Nikola and Zyzak, M. (STAR Collaboration) (2013) Elliptic flow of identified hadrons in Au+Au collisions at √sNN=7.7–62.4 GeV. Physical Review C, 88 (1). pp. 14902-25. ISSN 0556-2813

[img]
Preview
PDF - Published Version
Language: English

Download (7MB) | Preview

Abstract

Measurements of the elliptic flow, v2, of identified hadrons (π±, K ±, K0s, p, p¯, ϕ, Λ, Λ¯, Ξ−, Ξ¯+, Ω−, Ω¯+) in Au+Au collisions at √sNN= 7.7, 11.5, 19.6, 27, 39 and 62.4 GeV are presented. The measurements were done at mid-rapidity using the Time Projection Chamber and the Time-of-Flight detectors of the STAR experiment during the Beam Energy Scan program at RHIC. A significant difference in the v2 values for particles and the corresponding anti-particles was observed at all transverse momenta for the first time. The difference increases with decreasing center-of-mass energy, √sNN (or increasing baryon chemical potential, μB) and is larger for the baryons as compared to the mesons. This implies that particles and anti-particles are no longer consistent with the universal number-of-constituent quark (NCQ) scaling of v2 that was observed at √sNN= 200 GeV. However, for the group of particles NCQ scaling at (mT−m0)/nq> 0.4 GeV/c2 is not violated within ±10%. The v2 values for ϕ mesons at 7.7 and 11.5 GeV are approximately two standard deviations from the trend defined by the other hadrons at the highest measured pT values.

Item Type: Article
Keywords: elliptic flow, hadrons, AuAu, STAR
Date: July 2013
Subjects: NATURAL SCIENCES > Physics
Additional Information: Copyright (2013) 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 09:54
Last Modified: 23 Feb 2016 15:22
URI: http://digre.pmf.unizg.hr/id/eprint/2238

Actions (login required)

View Item View Item