Exploring axial U(1) restoration in a modified 2+1 flavor Polyakov–quark–meson model Suraj Kumar Rai and Vivek Kumar Tiwari Eur. Phys. J. Plus, 135 10 (2020) 844 Published online: 19 October 2020 DOI: 10.1140/epjp/s13360-020-00851-5