Kaon Flavour Physics Strikes Back

TL;DR

This paper highlights the rising importance of kaon flavour physics in detecting new physics, focusing on rare decay measurements and their correlations with other observables, which could reveal short-distance scale new physics.

Contribution

It emphasizes the potential of upcoming measurements and correlations in kaon decays to uncover new physics beyond the Standard Model.

Findings

Progress in lattice QCD and large N dual QCD suggests a possible flavour anomaly.

Correlations among various kaon decay observables can help identify new physics.

Upcoming experiments like NA62 and KOTO are crucial for this search.

Abstract

In this short presentation I emphasize the increased importance of kaon flavour physics in the search for new physics (NP) that we should witness in the rest of this decade and in the next decade. The main actors will be the branching ratios for the rare decays $K^+\rightarrow\pi^+\nu\bar\nu$ and $K_{L}\rightarrow\pi^0\nu\bar\nu$, to be measured by NA62 and KOTO, and their correlations with the ratio $\varepsilon'/\varepsilon$ on which recently progress by lattice QCD and large $N$ dual QCD approach has been made implying a new flavour anomaly. Further correlations of $K^+\rightarrow\pi^+\nu\bar\nu$, $K_{L}\rightarrow\pi^0\nu\bar\nu$ and $\varepsilon'/\varepsilon$ with $\varepsilon_K$, $\Delta M_K$, $K_L\to\mu^+\mu^-$ and $K_L\to\pi^0\ell^+\ell^-$ will help us to identify indirectly possible NP at short distance scales. This talk summarizes the present highlights of this fascinating field including some results from concrete NP scenarios.