Nuclear modification factors of phi mesons in d + Au, Cu + Cu, and Au + Au collisions at root sNN = 200 GeV
The PHENIX experiment at the Relativistic Heavy Ion Collider has performed systematic measurements of {phi} meson production in the K{sup +}K{sup -} decay channel at midrapidity in p+p, d+Au, Cu+Cu, and Au+Au collisions at {radical}s{sub NN} = 200 GeV. Results are presented on the {phi} invariant yield and the nuclear modification factor R{sub AA} for Au+Au and Cu+Cu, and R{sub dA} for d+Au collisions, studied as a function of transverse momentum (1 < p{sub T} < 7 GeV/c) and centrality. In central and midcentral Au+Au collisions, the R{sub AA} of {phi} exhibits a suppression relative to expectations from binary scaled p+p results. The amount of suppression is smaller than that of the {pi}{sup 0} and the {eta} in the intermediate p{sub T} range (2-5 GeV/c), whereas, at higher p{sub T}, the {phi}, {pi}{sup 0}, and {eta} show similar suppression. The baryon (proton and antiproton) excess observed in central Au+Au collisions at intermediate p{sub T} is not observed for the {phi} meson despite the similar masses of the proton and the {phi}. This suggests that the excess is linked to the number of valence quarks in the hadron rather than its mass. The difference gradually disappears with decreasing centrality, and, for peripheral collisions, the R{sub AA} values for both particle species are consistent with binary scaling. Cu+Cu collisions show the same yield and suppression as Au+Au collisions for the same number of N{sub part}. The R{sub dA} of {phi} shows no evidence for cold nuclear effects within uncertainties.
- Research Organization:
- Brookhaven National Lab. (BNL), Upton, NY (United States). Relativistic Heavy Ion Collider (RHIC)
- Sponsoring Organization:
- DOE - OFFICE OF SCIENCE
- DOE Contract Number:
- DE-AC02-98CH10886
- OSTI ID:
- 1019460
- Report Number(s):
- BNL-94836-2011-JA; R&D Project: PO 003; KB0201021; TRN: US1103623
- Journal Information:
- Physical Review C, Vol. 83, Issue 2; ISSN 0556-2813
- Country of Publication:
- United States
- Language:
- English
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