Dynamical dissociation of quarkonia by wave function decoherence

Abstract

We investigate the real-time evolution of quarkonium bound states in a quark-gluon plasma in one dimension using an improved QCD-based stochastic potential model. This model describes the quarkonium dynamics in terms of a Schr\"odinger equation with an in-medium potential and two noise terms encoding the residual interactions between the heavy quarks and the medium. The probabilities of bound states in a static medium and in a boost-invariantly expanding quark-gluon plasma are discussed. We draw two conclusions from our results: One is that the outcome of the stochastic potential model is qualitatively consistent with the experimental data in relativistic heavy-ion collisions. The other is that the noise plays an important role in order to describe quarkonium dynamics in medium; in particular, it causes decoherence of the quarkonium wave function. The effectiveness of decoherence is controlled by a new length scale ${l}_{\mathrm{corr}}$. It represents the noise correlation length and its effect has not been included in existing phenomenological studies.