Effects of multiple scattering in cold nuclear matter on J/psi suppression and P2T in heavy ion collisions
Physics Letters B 644,2-3 (2007) 119-125;
Coherent multiple scatterings of c (c) over bar quark pairs in the environment of heavy ion collisions have been used in a previous work by Qiu et al. [J. Qiu, J.P. Vary, X. Zhang, Phys. Rev. Lett. 88 (2002) 232301; J. Qiu, J.P. Vary, X. Zhang, Nucl. Phys. A 698 (2002) 571, nuel-th/0106040] to study J/psi suppression. That model suggests that heavy quark re-scatterings in a cold nuclear medium can completely explain the centrality dependence of the observed J/psi suppression in Pb + Pb collisions at the SPS [M.C. Abreu, et al., NA50 Collaboration, Phys. Lett. B 521 (2001) 195]. Their calculations also revealed significant differences under the assumptions of a color singlet or color octet production mechanism. A more recent analytic calculation [H. Fujii, Phys. Rev. C 67 (2003) 031901], which includes incoherent final-state re-scatterings with explicit momentum transfer fluctuations in three dimensions, indicates much less suppression and little sensitivity to the production mechanism. In this Letter, we study simultaneously both the J/psi suppression and PT modifications, at SPS and RHIC energies. We mainly focus on incoherent momentum transfer fluctuations in two dimensions, which is more appropriate for the heavy-ion collision kinematics. Our analytic and Monte Carlo calculations reinforce the analytic results in [H. Fujii, Phys. Rev. C 67 (2003) 031901]. Additionally, we find that the experimental J/psi suppression and < p(T)(2)> from nucleus-nucleus collisions at the SPS or RHIC cannot simultaneously be described in this incoherent multiple scattering framework for any value of the fluctuation strength parameter < k(T)(2)> (c) 2006 Elsevier B.V. All rights reserved.
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