Effect of momentum anisotropy on quark matter in the quark-meson model * *Supported by the National Natural Science Foundation of China (11935007) and the Fundamental Research Funds for the Central Universities (2020CXZZ107)

Abstract

We investigate the chiral phase structure of quark matter with spheroidal momentum-space anisotropy specified by one anisotropy parameter in the 2+1 flavor quark-meson model. We find that the chiral phase diagram and the location of the critical endpoint (CEP) are significantly affected by the value of . With an increase in , the CEP is shifted to lower temperatures and higher quark chemical potentials. In addition, the temperature of the CEP is more sensitive to the anisotropy parameter than the corresponding quark chemical potential, which is the opposite to that from the finite system volume effect. The effects of the momentum anisotropy on the thermodynamic properties and scalar (pseudoscalar) meson masses are also studied at the vanishing quark chemical potential. The numerical results reveal that an increase in can hinder the restoration of chiral symmetry. We also find that shear viscosity and electrical conductivity decrease as increases. However, the bulk viscosity exhibits a significant non-trivial behavior with in the entire temperature domain of interest.