KL−KSMass Difference from Lattice QCD

Abstract

We will report on the first full calculation of the K L − K S mass difference in lattice QCD. The calculation is performed on a 2+1 flavor, domain wall fermion, 243ÃŮ64 ensemble with a 329 MeV pion mass and a 575 MeV kaon mass. Both double penguin diagrams and disconnected diagrams are included in this calculation. The calculation is made finite through the GIM mechanism by introducing a 949 MeV valence charm quark. While the double penguin diagrams contribute a very small fraction to the mass difference, ther…