Measurements of ϕ meson production in relativistic heavy-ion collisions at the BNL Relativistic Heavy Ion Collider (RHIC)

Abelev, B. I. and Planinić, Mirko and Poljak, Nikola and Zuo, J. X. (STAR Collaboration) (2009) Measurements of ϕ meson production in relativistic heavy-ion collisions at the BNL Relativistic Heavy Ion Collider (RHIC). Physical Review C, 79 (6). pp. 64903-20. ISSN 0556-2813

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Abstract

We present results for the measurement of ϕ meson production via its charged kaon decay channel ϕ→K+K− in Au+Au collisions at √sNN=62.4,130, and 200 GeV, and in p+p and d+Au collisions at √sNN=200 GeV from the STAR experiment at the BNL Relativistic Heavy Ion Collider (RHIC). The midrapidity (|y|<0.5) ϕ meson transverse momentum (pT) spectra in central Au+Au collisions are found to be well described by a single exponential distribution. On the other hand, the pT spectra from p+p, d+Au, and peripheral Au+Au collisions show power-law tails at intermediate and high pT and are described better by Levy distributions. The constant ϕ/K− yield ratio vs beam species, collision centrality, and colliding energy is in contradiction with expectations from models having kaon coalescence as the dominant mechanism for ϕ production at RHIC. The Ω/ϕ yield ratio as a function of pT is consistent with a model based on the recombination of thermal s quarks up to pT~4 GeV/c, but disagrees at higher transverse momenta. The measured nuclear modification factor, RdAu, for the ϕ meson increases above unity at intermediate pT, similar to that for pions and protons, while RAA is suppressed due to the energy loss effect in central Au+Au collisions. Number of constituent quark scaling of both Rcp and v2 for the ϕ meson with respect to other hadrons in Au+Au collisions at √sNN=200 GeV at intermediate pT is observed. These observations support quark coalescence as being the dominant mechanism of hadronization in the intermediate pT region at RHIC.

Item Type: Article
Date: June 2009
Subjects: NATURAL SCIENCES > Physics
Additional Information: Copyright (2009) by the American Physical Society.
Divisions: Faculty of Science > Department of Physics
Publisher: American Physical Society
Depositing User: Gordana Stubičan Ladešić
Date Deposited: 10 Jun 2014 11:45
Last Modified: 10 Jun 2014 11:53
URI: http://digre.pmf.unizg.hr/id/eprint/2331

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