1305.7302 (Hao-jie Xu et al.)

Charm quarks in medium and their contribution to di-electron spectra in
relativistic heavy ion collisions    [PDF]

Hao-jie Xu, Xin Dong, Li-juan Ruan, Qun Wang, Zhang-bu Xu, Yi-fei Zhang

We study the dynamics of charm quarks in the partonic medium and its implication to the di-electron spectra in high energy heavy ion collisions. The charm quarks traversing the thermal medium is simulated by the relativistic Langevin equation for elastic scatterings of charm quarks by thermal partons in a hydrodynamically expanding fireball. The transport coefficients of charm quarks are calculated by the in-medium T-matrix method, where a static heavy quark potential is used with parameters by fitting the lattice QCD results. The di-electron invariant mass spectra are computed in the most central collisions and are compared to the STAR preliminary data. The agreement is as good as the previous results. The angular correlations of di-electrons are almost the same in p+p and Au+Au collisions in the mass range 1.1View original: http://arxiv.org/abs/1305.7302