Abstract:Quarkonia are bound states of a heavy quark pair and have been utilized to study its surrounding environment, including the QCD vacuum. In the relativistic heavy-ion collisions, suppression of quarkonia yield has been considered as an ideal signal for the experimental production of deconfined matter, the quark-gluon plasma (QGP).

In the last decade, this problem has been reconsidered using the framework of open quantum systems. In the colloquium, I will first give a general introduction to decoherence and dissipation and their description by open system approach. Then, I will apply the method to derive quantum evolution equations (Lindblad equations) of quarkonia in various regimes and show some recent numerical simulations of these Lindblad equations.