Suppression of Υ production in d + Au and Au + Au collisions at √sN N = 200 GeV

Adamczyk, L. and Planinić, Mirko and Poljak, Nikola (STAR Collaboration) (2014) Suppression of Υ production in d + Au and Au + Au collisions at √sN N = 200 GeV. Physics Letters B, 735. pp. 127-137. ISSN 0370-2693

[img]
Preview
PDF - Published Version
Available under License Creative Commons Attribution.
Language: English

Download (1MB) | Preview

Abstract

We report measurements of Υ meson production in p + p, d + Au, and Au + Au collisions using the STAR detector at RHIC. We compare the Υ yield to the measured cross section in p + p collisions in order to quantify any modifications of the yield in cold nuclear matter using d+Au data and in hot nuclear matter using Au+Au data separated into three centrality classes. Our p+ p measurement is based on three times the statistics of our previous result. We obtain a nuclear modification factor for Υ (1S + 2S + 3S) in the rapidity range |y| < 1 in d + Au collisions of RdAu = 0.79 ± 0.24(stat.) ± 0.03(syst.) ± 0.10(p + p syst.). A comparison with models including shadowing and initial state parton energy loss indicates the presence of additional cold-nuclear matter suppression. Similarly, in the top 10% most-central Au + Au collisions, we measure a nuclear modification factor of R A A = 0.49 ± 0.1(stat.) ± 0.02(syst.) ± 0.06(p + p syst.), which is a larger suppression factor than that seen in cold nuclear matter. Our results are consistent with complete suppression of excited-state Υ mesons in Au + Au collisions. The additional suppression in Au + Au is consistent with the level expected in model calculations that include the presence of a hot, deconfined Quark–Gluon Plasma. However, understanding the suppression seen in d + Au is still needed before any definitive statements about the nature of the suppression in Au + Au can be made

Item Type: Article
Keywords: suppresion, upsilon, STAR
Date: 30 July 2014
Subjects: NATURAL SCIENCES > Physics
Additional Information: © 2014 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/3.0/). Funded by SCOAP3. Received 13 December 2013 . Received in revised form 23 April 2014. Accepted 11 June 2014. Available online 16 June 2014.
Divisions: Faculty of Science > Department of Physics
Publisher: Elsevier
Depositing User: Nikola Poljak
Date Deposited: 06 Feb 2015 19:41
Last Modified: 29 May 2016 20:28
URI: http://digre.pmf.unizg.hr/id/eprint/3653

Actions (login required)

View Item View Item