Emerging lattice approach to the K-Unitarity Triangle

TL;DR

Recent advances in lattice calculations for Kaon processes are enabling the construction of a Kaon-based unitarity triangle, which, combined with B-physics, will enhance tests of the Standard Model and constrain new physics.

Contribution

The paper highlights recent progress in lattice QCD calculations for Kaon decays and mixing, paving the way for a Kaon-based unitarity triangle.

Findings

Lattice results for $K o \pi \pi$, $\Delta M_K$, and rare K-decays have significantly improved.

Construction of a Kaon unitarity triangle from lattice and experimental data is becoming feasible.

This approach will enable more stringent tests of the Standard Model.

Abstract

It has been clear for past many years that in low energy observables new physics can only appear as a perturbation. Therefore precise theoretical predictions and precise experimental measurements have become mandatory. Here we draw attention to the significant advances that have been made on the lattice in recent years in $K\to \pi \pi$, $\Delta M_K$, the long-distance part of $\varepsilon$ and rare K-decays. Thus, in conjunction with experiments, the construction of a unitarity triangle purely from Kaon physics should soon become feasible. Along with the B-unitarity triangle, this should allow for more stringent tests of the Standard Model and tighter constraints on new physics.