Flavor-independent yield of high-$p_T$ hadrons from nuclear collisions

Abstract: Data on high-$p_T$ hadron production in heavy ion collisions at Feynman $x_F=0$ indicate at universality of the observed nuclear suppression. Our analysis of the production mechanisms demonstrates important role of the color transparency effects which make the survival probability of a quark-antiquark dipole independent of the quark flavor, provided that the hadron wave function is formed outside the medium. The latter condition imposes restrictions on the range of $p_T$, which should be sufficiently high to make the nuclear suppression universal. We also found that the in-medium broadening rate $\hat q$ (frequently called transport coefficient) significantly depends on the quark flavor, diminishing for heavy quarks.