Energy loss of heavy quarkonia in hot QCD plasmas

Abstract

We compute the energy loss of heavy quarkonia in high temperature QCD plasmas and investigate the energy loss effects on quarkonium suppression. Based on the effective vertex derived from the Bethe-Salpeter amplitude for quarkonium, the collisional and radiative energy loss are determined by quarkonium-gluon elastic scattering and the associated gluon-bremsstrahlung, respectively. In the energy regime $E<m_{\Upsilon}^2/T$ the collisional energy loss is dominant over the radiative one, and the total energy loss increases with the plasma temperature and the initial energy of quarkonium. Our numerical analysis indicates that the medium-induced energy loss of the $\Upsilon$(1S) results in stronger suppression at higher momentum, although the energy loss effects are found to be small compared with the previous estimates of quarkonium dissociation in heavy-ion collisions.