Kaon-kaon scattering at maximal isospin from $N_f=2+1+1$ twisted mass lattice QCD

TL;DR

This study computes the kaon-kaon scattering length at maximal isospin using lattice QCD with 2+1+1 flavors, providing a precise value after chiral and continuum extrapolations.

Contribution

First lattice QCD calculation of kaon-kaon scattering length at maximal isospin with 2+1+1 flavors across multiple pion masses and lattice spacings.

Findings

Calculated scattering length $a_0^{I=1}$ at the physical point.

Provided a value of $M_K a_0 =-0.397(11)(_{-8}^{+0})$ after extrapolation.

Compared results with other lattice studies.

Abstract

We present results for the interaction of two kaons at maximal isospin. The calculation is based on 2+1+1 flavour gauge configurations generated by the ETM Collaboration (ETMC) featuring pion masses ranging from about 230 MeV to 450 MeV at three values of the lattice spacing. The elastic scattering length $a_0^{I=1}$ is calculated at several values of the bare strange quark and light quark masses. We find $M_K a_0 =-0.397(11)(_{-8}^{+0})$ as the result of a chiral and continuum extrapolation to the physical point. This number is compared to other lattice results.