Numerical Study of the Roberge-Weiss Transition

Abstract

We study the Roberge-Weiss phase transition numerically. The phase transition is associated with the discontinuities in the quark-number density at specific values of imaginary quark chemical potential. We parameterize the quark number density ${\rho }_q$ by the polynomial fit function to compute the canonical partition functions. We demonstrate that this approach provides a good framework for analyzing lattice QCD data at finite density and a high temperature. We show numerically that at high temperature, the Lee-Yang zeros lie on the negative real semi-axis provided that the high-quark-number contributions to the grand canonical partition function are taken into account. These Lee-Yang zeros have nonzero linear density, which signals the Roberge-Weiss phase transition. We demonstrate that this density agrees with the quark density discontinuity at the transition line.

11 pages, 5 figures; Fig.1, Fig.4 improved, typos corrected, discussion of statistical errors added

References in corpus (7)

• The strongly interacting Quark Gluon Plasma, and the critical behaviour of QCD at imaginary chemical potential
• The chiral phase transition in two-flavor QCD from imaginary chemical potential
• Taylor expansions and Padé approximants for cumulants of conserved charge fluctuations at non-vanishing chemical potentials
• The Roberge-Weiss endpoint in N_f = 2 QCD
• Lee-Yang zero distribution of high temperature QCD and Roberge-Weiss phase transition
• Quark number densities at imaginary chemical potential in $N_f=2$ lattice QCD with Wilson fermions and its model analyses
• Localization properties of Dirac modes at the Roberge-Weiss phase transition