The KL - KS Mass Difference

Ziyuan Bai,Norman H Christ,Christopher T Sachrajda,M Della Morte,C Pena Ruano,E Gámiz Sánchez,P Fritzsch

doi:10.1051/epjconf/201817513017

Ziyuan Bai, Norman H Christ + Show 5 more

Open Access

https://doi.org/10.1051/epjconf/201817513017

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Abstract

We review the status of the RBC-UKQCD collaborations’ computations of the KL-KS mass difference. After a brief discussion of the theoretical framework which had been developed previously by the collaboration, we describe our latest computation, performed at physical quark masses, and present our preliminary result mKL - mKS = (5.5 ± 1.70) × 10-12 MeV.

Highlights

IntroductionThe value of the KL-KS mass difference, ∆mK ≡ mKL − mKS = 3.483(6) × 10−12 MeV, is truly tiny on the scale of ΛQCD
The value of the KL-KS mass difference, ∆mK ≡ mKL − mKS = 3.483(6) × 10−12 MeV, is truly tiny on the scale of ΛQCD. This flavour-changing neutral current (FCNC) process is an excellent one in which to search for the effects of new physics
The mass difference ∆mK is obtained from second order weak perturbation theory, :

Summary

Introduction

The value of the KL-KS mass difference, ∆mK ≡ mKL − mKS = 3.483(6) × 10−12 MeV, is truly tiny on the scale of ΛQCD. This flavour-changing neutral current (FCNC) process is an excellent one in which to search for the effects of new physics. (s · · · d)(s · · · experimental d), where the ellipses represent ∆mK in the SM to 10% accuracy possible we pwhoyuslidcsbteossecnaslietsivwe htoicshcaarleesuΛnre>∼ac(h1a0b3le−d1i0re4c)tTlyeVa.t. This illustrates the sensitivity the Large Hadron Collider. The calculation of ∆mK is one component of the RBC-UKQCD collaborations’ programme of computations of long-distance contributions in kaon physics, requiring the evaluation of matrix elements of bilocal operators of the form d4 x f | T Q1(x) Q2(0) | i

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