Consistent chiral limit in on-shell renormalized quark-meson model with ChPT scaling

Abstract

Chiral perturbation theory (ChPT) predicted scaling of the pion,~kaon decay constants $f_{\pi}, f_{K} $ and $M_{\eta}^2 = m_{\eta}^2 + m_{\eta^{\prime}}^2 $ has been used in the renormalized $2+1$ flavor quark-meson (RQM) model,~to find a consistent path to chiral limit as the $\pi \ \text{and} \ K $ meson masses approach zero.~The left side of the Columbia plot is generated free from any ambiguity or heuiristic adjustment in the model parameter fixing away from the physical point. The on-shell renormalization of parameters and consistent treatment of the divergent quark one-loop vacuum fluctuations in the RQM model,~make the axial $U_{A}(1)$ anomaly significantly stronger and the light (strange) explicit chiral symmetry breaking strength becomes weaker by a small (relatively large) amount.~The first order chiral transition region in the $m_{\pi}-m_{K}$ and $\mu-m_{K}$ planes of Columbia plot,~increases due to the above novel features of the RQM model.~Comparing the softening effect of quark one-loop vacuum fluctuation on the chiral transition,~it looks overestimated in a recent functional renormalization group study.