Kaon oscillations in the Standard Model and Beyond using Nf=2 dynamical quarks

TL;DR

This study non-perturbatively calculates B-parameters for four-fermion operators relevant to Kaon oscillations within the Standard Model and supersymmetry, using lattice QCD simulations with dynamical quarks.

Contribution

It provides the first non-perturbative determination of B-parameters for all relevant operators with Nf=2 dynamical quarks, improving precision in Kaon oscillation studies.

Findings

Preliminary BK(RGI) value is 0.73(3)(3).

Operators are renormalized non-perturbatively in RI/MOM scheme.

Discretization effects are minimized using Osterwalder-Seiler variant of Twisted Mass action.

Abstract

We compute non-perturbatively the B-parameters of the complete basis of four-fermion operators needed to study the Kaon oscillations in the SM and in its supersymmetric extension. We perform numerical simulations with two dynamical maximally twisted sea quarks at three values of the lattice spacing on configurations generated by the ETMC. Unwanted operator mixings and O(a) discretization effects are removed by discretizing the valence quarks with a suitable Osterwalder-Seiler variant of the Twisted Mass action. Operators are renormalized non-perturbatively in the RI/MOM scheme. Our preliminary result for BK(RGI) is 0.73(3)(3).