https://doi.org/10.1140/epjp/s13360-020-00851-5
Regular Article
Exploring axial U(1) restoration in a modified 2+1 flavor Polyakov–quark–meson model
Department of Physics, University of Allahabad, 211002, Allahabad, India
Received:
23
October
2019
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.
© Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2020
