6533b7d6fe1ef96bd12664ef

RESEARCH PRODUCT

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The in-medium dynamics of heavy particles are governed by transport coefficients. The heavy quark momentum diffusion coefficient, $\ensuremath{\kappa}$, is an object of special interest in the literature, but one which has proven notoriously difficult to estimate, despite the fact that it has been computed by weak-coupling methods at next-to-leading order accuracy, and by lattice simulations of the pure SU(3) gauge theory. Another coefficient, $\ensuremath{\gamma}$, has been recently identified. It can be understood as the dispersive counterpart of $\ensuremath{\kappa}$. Little is known about $\ensuremath{\gamma}$. Both $\ensuremath{\kappa}$ and $\ensuremath{\gamma}$ are, however, of foremost importance in heavy quarkonium physics as they entirely determine the in and out of equilibrium dynamics of quarkonium in a medium, if the evolution of the density matrix is Markovian, and the motion, quantum Brownian; the medium could be a strongly or weakly coupled plasma. In this paper, using the relation between $\ensuremath{\kappa}$, $\ensuremath{\gamma}$ and the quarkonium in-medium width and mass shift respectively, we evaluate the two coefficients from existing $2+1$ flavor lattice QCD data. The resulting range for $\ensuremath{\kappa}$ is consistent with earlier determinations, the one for $\ensuremath{\gamma}$ is the first nonperturbative determination of this quantity.