The QCD Running Coupling at Finite Temperature and Density

الأصل · EN

We present for the first time a self-contained calculation of the QCD running coupling at finite temperature and quark chemical potential, alphaₛ(T, mu), based on a semiclassical background field method. The hard thermal/dense loop results on the Debye screening mass are recovered in a first approximation. The final result can be interpreted as the ordinary zero temperature running coupling, with momenta replaced by in-medium scales Lambda: at high density and zero temperature, the quark scale is set by Lambda 24.4 mu. At high temperature and moderate densities, the quark in-medium scale reads Lambda² [2.91 T]² + [1.91 mu]², which resembles the naive phenomenological estimate Lambda² = (pi T)² + mu².