Quasinormal modes and dispersion relations for quarkonium in a plasma

Abstract

Recent investigations show that the thermal spectral function of heavy bb and cc vector mesons can be described using holography. These studies consider a bottom up model that captures the heavy flavour spectroscopy of masses and decay constants in the vacuum and is consistently extended to finite temperature. The corresponding spectral functions provide a picture of the dissociation process in terms of the decrease of the quasi-state peaks with temperature.Another related tool that provides important information about the thermal behaviour is the analysis of the quasinormal modes. They are field solutions in a curved background assumed to represent, in gauge/gravity duality, quasi-particle states in a thermal medium. The associated complex frequencies are related to the thermal mass and width. We present here the calculation of quasinormal modes for charmonium and bottomonium using the holographic approach. The temperature dependence of mass and thermal width are investigated. Solutions corresponding to heavy mesons moving into the plasma are also studied. They provide the dependence of the real and imaginary parts of the frequency with the quasi-particle momenta, the so called dispersion relations.

Quasinormal modes for quarkonium in a plasma with magnetic fields

“…As discussed in refs. [3][4][5], a consistent description of heavy vector mesons in a thermal medium is obtained by considering a 5-d anti-de Sitter black hole space-time…”

“…The model revised in this section was applied in refs [3,4] to calculate the spectral functions with and without magnetic fields and then in [5] to find out the quasinormal modes for a thermal medium without magnetic field.…”

“…We will extend the calculation of quasinormal modes presented in [5] to the case when a magnetic field is present. The dependence of the real and imaginary part of the frequency on the magnetic field will be investigated for charmonium and bottomonium states.…”

“…A consistent description of the dissociation process using a holographic model containing three energy parameters was obtained in Refs. [3][4][5]. These parameters have a simple physical interpretation.…”

Configuration entropy and stability of bottomonium radial excitations in a plasma with magnetic fields

“…Then an improved version, that we will use here, was developed in Refs. [39][40][41][42]. This model provides good estimates not only for the quarkonium masses, but also for the decay constants.…”