Nuclear Modification Factors of phi Mesons in d+Au, Cu+Cu and Au+Au Collisions at s_NN = 200 GeV

Journal Article · Fri Dec 31 23:00:00 EST 2010 · Physical Review C

DOI:https://doi.org/10.1103/PhysRevC.83.024909· OSTI ID:1005191

Adare, A. ^[1]; Awes, Terry C ^[2]; Cianciolo, Vince ^[2]; Efremenko, Yuri ^[3]; Enokizono, Akitomo ^[4]; Read, Jr, Kenneth F ^[2]; Silvermyr, David O ^[2]; Sorensen, Soren P ^[5]; Stankus, Paul W ^[2]

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1. University of Colorado, Boulder
2. ORNL
3. University of Tennessee, Knoxville (UTK) & Oak Ridge National Laboratory (ORNL)
4. Oak Ridge National Laboratory (ORNL)
5. University of Tennessee, Knoxville (UTK)

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: Oak Ridge National Laboratory (ORNL)
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1005191
• Journal Information: Physical Review C, Journal Name: Physical Review C Journal Issue: 2 Vol. 83; ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
74 ATOMIC AND MOLECULAR PHYSICS
BARYONS
DECAY
HADRONS
HEAVY IONS
MESONS
MODIFICATIONS
PERIPHERAL COLLISIONS
PRODUCTION
PROTONS
QUARKS
TRANSVERSE MOMENTUM
VALENCE