Quark number susceptibilities from two-loop hard thermal loop perturbation theory

Abstract

We use the recently obtained two-loop hard thermal loop perturbation theory thermodynamics functions of a plasma of quarks and gluons to compute the diagonal second-and fourth-order quark number susceptibilities. The two-loop hard thermal loop perturbation theory thermodynamic functions used are reliable in the limit that the ratio of the quark chemical potential to temperature is small. Using this result, we are able to obtain (semi-)analytic expressions for the quark number susceptibilities at leading-and next-to-leading-order in hard thermal loop perturbation theory. We compare the hard thermal loop perturbation theory results with perturbative quantum chromodynamics calculations, a Polyakov-loop Nambu-Jona-Lasinio model calculation, and lattice quantum chromodynamics results.

Quark mass dependent collective excitations and quark number susceptibilities within the hard thermal loop approximation

“…There are various ways to calculate the QNS within the HTL resummation framework, such as (i) calculating pressure by expanding it at small Debye and thermal quark masses and then taking the double derivative of that pressure with respect to the chemical potential [6], (ii) using the fluctuation-dissipation theorem [21], and (iii) using two-loop approximately self-consistent Φ-derivable HTL resummation [17]. In the second and third methods, one uses quark quasiparticle poles ðω AE Þ to calculate the susceptibilities.…”

Three-loop HTLpt thermodynamics at finite temperature and chemical potential

“…HTLpt has been used to calculate thermodynamic functions at one loop HTLpt [40][41][42][43][44], at two loops [45][46][47][48], and at three loops at zero chemical potential [49][50][51][52][53][54] as well as at finite chemical potential [55]. Application of some hard-thermal-loop motivated approaches can be found in [56][57][58][59][60][61][62][63][64][65][66][67].…”

Vector meson spectral function and dilepton production rate in a hot and dense medium within an effective QCD approach

“…Nevertheless, at RHIC and LHC energies the maximum temperature reached is not very far from the phase transition temperature T c and a hot and dense matter created in these collisions is nonperturbative in nature (semi-QGP). So, most of the perturbative methods may not be applicable in this temperature domain but these methods, however, are very reliable and accurate at very high temperature [61][62][63][64] for usual weakly interacting QGP. In effective QCD model framework [32,33,[65][66][67][68][69], several studies have also been done in this direction.…”