Lattice calculations for B and K mixing

TL;DR

This paper reviews recent lattice calculations of B and K meson mixing parameters, which are crucial for testing the Standard Model against experimental data and require precise non-perturbative inputs.

Contribution

It summarizes recent advances in lattice QCD calculations of meson mixing parameters, highlighting their importance for CKM analysis and Standard Model tests.

Findings

Lattice calculations are approaching a few percent accuracy.

Recent results support the consistency of the Standard Model.

These calculations are essential for interpreting experimental measurements.

Abstract

The bag parameters and the decay constants of neutral B and K mesons were among the non-perturbative hadronic inputs to the classical CKM Unitarity Triangle Analysis. Thanks to the big amount of experimental information collected in the last few years at the B-factories and by the CDF collaboration, these matrix elements are now among the outputs of the unitarity fits, once the validity of the Standard Model has been postulated. Lattice calculations of the mixing amplitudes are still needed in order to make a test of the theory, provided that their statistical and systematic errors are under control at the level of a few percent. Here we review some of the recent lattice calculations of these quantities.