Remarks on the hadronic matrix elements relevant to the SUSY K-Kbar mixing amplitude

TL;DR

This paper calculates 1-loop chiral corrections to bag parameters relevant for SUSY K-Kbar mixing, proposing methods to reduce systematic errors in lattice QCD results and extending the analysis to 2-loop corrections and related operators.

Contribution

It introduces a systematic approach to combine bag parameters and auxiliary quantities, reducing errors in lattice QCD calculations for SUSY K-Kbar mixing.

Findings

Reduction of systematic errors in bag parameter calculations.

Validation of methods even after including 2-loop corrections.

Application to K to pi electroweak penguin operators.

Abstract

We compute the 1-loop chiral corrections to the bag parameters which are needed for the discussion of the SUSY K-Kbar mixing problem in both finite and infinite volume. We then show how the bag parameters can be combined among themselves and with some auxiliary quantities and thus sensibly reduce the systematic errors due to chiral extrapolations as well as those due to finite volume artefacts present in the results obtained from lattice QCD. We also show that in some cases these advantages remain as such even after including the 2-loop chiral corrections. Similar discussion is also made for the K --> pi electro-weak penguin operators.