Kaon processes in general 2HDM

TL;DR

This paper explores how a general two Higgs doublet model can produce significant new physics effects in kaon mixing, CP violation, and rare decays, while remaining consistent with B physics constraints.

Contribution

It analyzes the impact of top quark related exotic couplings in the 2HDM on kaon processes and highlights correlations that can distinguish Higgs mass scales.

Findings

Large NP effects in kaon sector possible with combined flavor conserving and violating interactions.

Correlations between $ ext{ε}_K$, $K^+ o uar u$, and $B_s o uar u$ can differentiate Higgs mass scales.

Model remains consistent with B physics constraints despite sizable effects.

Abstract

We discuss new physics (NP) contributions to kaon mixing parameter $\varepsilon_K$, direct CP violation parameter $\varepsilon^\prime/\varepsilon$ of $K\to \pi\pi$, and rare decays $K^+\to \pi^+\nu\bar\nu$, $K_L\to \pi^0\nu\bar\nu$ and $K_{L, S}\to \mu^+ \mu^- $ in the context of general two Higgs doublet model. We focus on contributions of top quark related exotic couplings, and show that simultaneous presence of flavor conserving and flavor violating interactions can lead to large NP effects in kaon sector, while being consistent with the stringent constraints from B physics observables such as $B_{s(d)}$-$\bar B_{s(d)}$ mixing, $B_s\to \mu^+ \mu^-$, and $b\to s\gamma$. We stress on the importance of correlations between $\varepsilon_K$, $K^+\to \pi^+\nu\bar\nu$ and $B_s\to \mu^+ \mu^-$ that can be exploited to distinguish the parameter space corresponding to a light (sub-TeV) or heavy (TeV) scale charged Higgs boson.