0000000000404385
AUTHOR
Miguel ÁNgel Escobedo
Approach to equilibrium of a quarkonium in a quark-gluon plasma
We derive equations of motion for the reduced density matrix of a heavy quarkonium in contact with a quark-gluon plasma in thermal equilibrium. These equations allow in particular a proper treatment of the regime when the temperature of the plasma is comparable to the binding energy of the quarkonium. These equations are used to study how the quarkonium approaches equilibrium with the plasma, and we discuss the corresponding entropy increase, or free energy decrease, depending on the temperature regime. The effect of collisions can be accounted for by the generalization of the imaginary potential introduced in previous studies, and from which collision rates are derived. An important outcom…
Quarkonium suppression in heavy-ion collisions: an open quantum system approach
We address the evolution of heavy-quarkonium states in an expanding quark-gluon plasma by implementing effective field theory techniques in the framework of open quantum systems. In this setting we compute the nuclear modification factors for quarkonia that are $S$-wave Coulombic bound states in a strongly-coupled quark-gluon plasma. The calculation is performed at an accuracy that is leading-order in the heavy-quark density expansion and next-to-leading order in the multipole expansion. The quarkonium density-matrix evolution equations can be written in the Lindblad form, and, hence, they account for both dissociation and recombination. Thermal mass shifts, thermal widths and the Lindblad …
Effective Field Theory and Lattice QCD approaches for hard probes in QCD matter
Hard Probes are an essential tool to discover the properties of the quark-gluon plasma created in heavy-ion collisions. The study of hard probes always involves taking into account very different energy scales, and this is precisely the situation in which Effective Fields Theories (EFTs) are useful. EFTs can be used to separate the short-distance and perturbative physics from the long-distance and non-perturbative. This method combined with Lattice QCD evaluations of the long-distance effects can provide accurate and first principles results. In this proceeding, I will report recent advances in this direction. Results from an EFT computation of quarkonium $R_{AA}$ at $\sqrt{s_{NN}}=5.02\,\t…