Exploring axial U(1) restoration in a modified 2+1 flavor Polyakov–quark–meson model
Department of Physics, University of Allahabad, 211002, Allahabad, India
Accepted: 9 October 2020
Published online: 19 October 2020
We report on the symmetry restoration resulting due to temperature dependence of the coefficient c(T) for the Kobayashi–Maskawa–’t Hooft determinant (KMT) term in a modified flavor Polyakov loop quark–meson model having fermionic vacuum correction term. Temperature dependence of KMT coupling c(T) drives the nonstrange condensate melting to significantly smaller temperatures in comparison with the constant c case. Further due to c(T), decreases from its vacuum value by 220 MeV near MeV after the chiral transition ( MeV). This is similar to the in-medium mass drop of at least 200 MeV as reported by Csorgo and Vertesi in Ref (Phys Rev Lett 105:182301, 2010; Phys Rev C 83:054903 2011), as an experimental signature of the effective restoration of symmetry. The pseudoscalar mixing angle achieves anti-ideal mixing in the influence of c(T). The meson becomes light quark system () at MeV and changes its identity with meson which becomes strange quark system (). The degenerated temperature variations of , meson masses merges with the temperature variations of the masses of degenerated , mesons near 275 MeV. It means that for c(T) when MeV, the restoration takes place at 1.75 MeV.
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