Bubble contributions to scalar correlators with mixed actions

TL;DR

This paper extends the calculation of bubble contributions in mixed-action chiral perturbation theory to scalar mesons $ _0$, $0$, and $ $, revealing complex pole structures and growth behaviors relevant for lattice QCD studies.

Contribution

It provides new analytical expressions for bubble contributions of multiple scalar mesons in mixed-action chiral perturbation theory, aiding lattice QCD analysis.

Findings

$ _0$ bubble contributions derived in MA$hi$PT.

$0$ bubble has two double poles.

$ $ bubble exhibits quadratic growth from double poles.

Abstract

WWithin mixed-action chiral perturbation theory (MA$\chi$PT), Sasa's derivation of the bubble contribution to scalar $a_0$ meson is extended to those of scalar $\kappa$ and $\sigma$ mesons. We revealed that $\kappa$ bubble has two double poles and $\sigma$ bubble contains a quadratic-in-$t^2$ growth factor stemming from the multiplication of two double poles for a general mass tuning of valence quarks and sea quarks. The corresponding preliminary analytical expressions in MA$\chi$PT with 2+1 chiral valence quarks and 2+1 staggered sea quarks will be helpful for lattice studies of scalar mesons.