The 33rd International Symposium on Lattice Field Theory (Lattice 2015)

Study of entropy production in Yang-Mills theory with use of Husimi function

17 Jul 2015, 17:50

20m

401 (Kobe International Conference Center)

Talk Nonzero Temperature and Density Nonzero Temperature and Density

Speaker

Hidekazu Tsukiji (YITP, Kyoto univ.)

Description

Understanding the themalization process in a pure quantum system is a challenge in theoretical physics. In this work, we explore possible thermalization mechanism in Yang-Mills(Y-M) theory by using a positive semi-definite quantum distribution function called Husimi function which is given by a coarse graining of Wigner function within the minimal uncertainty. Then entropy is defined in terms of the Husimi function, which is called the Husimi-Wehrl(H-W) entropy. We propose two numerical methods to calculate the H-W entropy. We find that it is feasible to apply the semi-classical approximation with the use of classical Y-M equation. It should be noted that the semi-classical approximation is valid in the systems of physical interest including the early stage of heavy-ion collisions. Using a product ansatz for the Husimi function, which is checked to give only some 10 % over estimate, we succeed in a numerical evaluation of H-W entropy of Y-M theory and show that it surely has a finite value and increases in time.

Presentation materials

Slides

Lattice2015.pdf