K0-K0bar Mixing with Wilson Fermions without Subtractions

TL;DR

This paper demonstrates a method to compute K0-K0bar mixing on the lattice without subtractions, leveraging Ward identities, achieving an accuracy of order a, the best possible without improvement.

Contribution

It introduces a technique using Ward identities to avoid subtractions in Wilson fermion calculations of K0-K0bar mixing, enhancing accuracy.

Findings

Achieves O(a) accuracy in mixing amplitude calculations.

Eliminates the need for subtraction of chiral symmetry breaking terms.

Provides a practical approach for lattice QCD computations of meson mixing.

Abstract

By using suitable Ward identities, we show that it is possible to compute K0-K0bar mixing without subtracting the terms generated by explicit chiral symmetry breaking present in Wilson-like lattice actions. The accuracy in the determination of the amplitudes is of O(a), which is the best one attainable in the absence of improvement.