QCD thermodynamics at intermediate coupling

May 24, 2011, 5:00 PM
Salon Haendel AB (Imperial Palace)

Salon Haendel AB

Imperial Palace

Allée Impérial 74000 Annecy, France Tél. : +33 4 50 09 30 00
Parallel QCD at high temperature and density QCD Phase diagram


Dr Nan Su (Bielefeld University)


The weak-coupling expansion of the QCD free energy is known to order g^6*log[g], however, the resulting series is poorly convergent at phenomenologically relevant temperatures. I will discuss how the gauge invariant hard-thermal-loop perturbation theory (HTLpt) reorganization of the calculation improves the convergence of the successive approximations to the QCD free energy. I will present new results of an HTLpt calculation of QCD thermodynamics to three loops. The results of this calculation are consistent with lattice data down to 2-3T_c. This is a non-trivial result since, in this temperature regime, the QCD coupling constant is neither infinitesimally weak nor infinitely strong with g~2, or equivalently alpha_s~0.3. Therefore, we have a crucial test of the quasiparticle picture in the intermediate coupling regime. Our results suggest that HTLpt provides a systematic framework that can be used to calculate static and dynamic quantities for temperatures relevant at LHC.

Primary authors

Prof. Jens Andersen (Norwegian University of Science and Technology) Mr Lars Leganger (Norwegian University of Science and Technology) Prof. Michael Strickland (Gettysburg College) Dr Nan Su (Bielefeld University)

Presentation materials