Lepton flavor (universality) violation in rare kaon decays

TL;DR

This paper explores how new physics explanations for B-meson and Higgs anomalies could also cause observable effects in rare kaon decays, highlighting experimental opportunities at NA62.

Contribution

It links B-physics anomalies to kaon decay processes via four-fermion operators, analyzing their potential impact and experimental testability.

Findings

Four-fermion operators relevant to B anomalies also affect kaon decays.

NA62 experiment can test these effects with improved sensitivity.

Minimal flavor violation assumptions guide the analysis.

Abstract

Recent anomalies in the decays of $B$ mesons and the Higgs boson provide hints towards lepton flavor (universality) violating physics beyond the Standard Model. We observe that four-fermion operators which can explain the $B$-physics anomalies have corresponding analogs in the kaon sector, and we analyze their impact on $K\to\pi\ell \ell'$ and $K\to\ell \ell'$ decays $(\ell=\mu,e)$. For these processes, we note the corresponding physics opportunities at the NA62 experiment. In particular, assuming minimal flavor violation, we comment on the required improvements in sensitivity necessary to test the $B$-physics anomalies in the kaon sector.