Results for the mass difference between the long- and short- lived K mesons for physical quark masses

TL;DR

This paper presents preliminary lattice QCD calculations of the mass difference between long- and short-lived neutral kaons using physical quark masses, with improved statistical precision.

Contribution

It provides new lattice QCD results for $ riangle m_K$ with increased Monte Carlo statistics and discusses systematic errors involved.

Findings

Preliminary results for $ riangle m_K$ with physical quark masses.

Enhanced statistical accuracy compared to previous calculations.

Discussion of systematic uncertainties in lattice QCD computations.

Abstract

The two neutral kaon states in nature, the $K_L$ (long-lived) and $K_S$ (short-lived) mesons, are the two time-evolution eigenstates of the $K^0 - \overline{K^0}$ mixing system. The prediction of their mass difference $\Delta m_K$ based on the Standard Model is an important goal of lattice QCD. In this article, I will present preliminary results from a calculation of $\Delta m_K$ performed on an ensemble of $64^3 \times 128$ gauge configurations with inverse lattice spacing of 2.36 GeV and physical quark masses. These new results come from 2.5 times the Monte Carlo statistics used for the result presented in last year's conference. Further discussion of the methods employed and the resulting systematic errors will be given.