Pion condensation in the two--flavor chiral quark model at finite baryochemical potential

Abstract

Pion condensation is studied at one--loop level and nonzero baryochemical potential in the framework of two flavor constituent quark model using the one--loop level optimized perturbation theory for the resummation of the perturbative series. A Landau type of analysis is presented for the investigation of the phase boundary between the pion condensed/non-condensed phases. The statement that the condensation starts at $\text{muI}=m_{\pi }$ is slightly modified by one--loop corrections. The second order critical surface is determined and analysed in the $\text{muI}-\text{muB}-T$ space. The $\text{muI}$ dependence of the one--loop level charged pion pole masses is also studied.

Comments: 12 pages, 5 figures, submitted to PRD