Some Applications of Hard Thermal Loop Perturbation Theory in Quark Gluon Plasma

TL;DR

This thesis applies hard-thermal-loop perturbation theory to study the thermodynamics of quark-gluon plasma, comparing results with lattice QCD data and exploring dilepton production in hot, dense matter.

Contribution

It demonstrates the effectiveness of HTL perturbation theory in calculating thermodynamic properties of QCD at finite temperature and chemical potential, including susceptibilities and dilepton rates.

Findings

Good agreement with lattice QCD data for thermodynamic quantities.

Successful calculation of quark number susceptibilities beyond leading order.

Consistent results for dilepton rates using perturbative and non-perturbative models.

Abstract

This thesis is mainly devoted to the study of thermodynamics for quantum Chromodynamics. In this thesis I apply hard-thermal-loop perturbation theory, which is a gauge-invariant reorganization of the conventional perturbative expansion for quantum gauge theories to study the thermodynamics of QCD in leading-order, next-to-leading-order and next-to-next-to-leading order at finite temperature and finite chemical potential. I also discuss about various order diagonal and off-diagonal quark number susceptibilities in leading order as well as beyond leading order. For all the observables, I compare our results with available lattice QCD data and we find good agreement. Along with the computation of thermodynamic quantities of hot and dense matter, I also discuss about low mass dilepton rate from hot and dense medium using both perturbative and non-perturbative models and compare them with those from lattice gauge theory and in-medium hadron gas.