Quark mass dependence of pseudoscalar masses and decay constants

TL;DR

This paper investigates how pseudoscalar meson masses and decay constants depend on sea and valence quark masses in two-flavor QCD, estimating low energy constants using lattice simulations with Wilson fermions.

Contribution

It provides a detailed lattice QCD study of quark mass dependence and estimates key low energy constants, incorporating ${ m O}(a)$ effects with chiral perturbation theory for Wilson fermions.

Findings

Estimated Gasser-Leutwyler low energy constants $L_4$, $L_5$, $L_6$, $L_8$.

Quantified pseudoscalar masses and decay constants dependence on quark masses.

Accounted for lattice artifacts using chiral perturbation theory for Wilson fermions.

Abstract

The dependence of pseudo-scalar masses and decay constants on the sea and valence quark masses is investigated in the pseudo-Goldstone boson sector of QCD with two light quark flavours. The sea quark masses are at present in the range ${1/3}m_s \leq m_{ud} \leq {2/3}m_s$ whereas the valence quark masses satisfy ${1/2}m_{sea} \leq m_{val} \leq 2m_{sea}$. The values of the Gasser-Leutwyler low energy constants $L_4$, $L_5$, $L_6$ and $L_8$ are estimated. The computation is done with the Wilson-quark lattice action at gauge coupling $\beta=5.1$ on $16^4$ lattices. ${\cal O}(a)$ effects are taken into account by applying chiral perturbation theory for the Wilson lattice action as proposed by Rupak and Shoresh.