Strange processes in general two Higgs doublet model

TL;DR

This paper investigates how the general two Higgs doublet model with extra Yukawa couplings affects kaon mixing, CP violation, and rare decays, highlighting unique sensitivities and correlations among these observables.

Contribution

It provides a detailed analysis of New Physics contributions in g2HDM to kaon observables and explores their potential to probe the exotic Higgs spectrum and TeV-scale charged Higgs bosons.

Findings

Kaon mixing and rare decays offer complementary probes of g2HDM.

K+→π+νν¯ decay is highly sensitive to TeV-scale charged Higgs.

Correlations between observables can distinguish g2HDM effects.

Abstract

In the general two Higgs doublet model (g2HDM) that has extra Yukawa couplings, we analyze their New Physics (NP) contributions to kaon mixing parameter $\varepsilon_K$, direct CP violation parameter $\varepsilon^\prime/\varepsilon$, and rare $K^+ \to \pi^+\nu\bar\nu$, $K_L \to \pi^0\nu\bar\nu$, and $K_{L, S} \to \mu^+ \mu^-$ decays. We study correlations between these observables, and call special attention to a unique complementarity of kaon mixing and rare $K\to \pi \nu\bar\nu$ decays in probing the exotic Higgs mass spectrum of g2HDM. The importance of kaon physics in probing NP vis-\`a-vis B physics is stressed. One unexpected feature we uncover is the special sensitivity of $K^+ \to \pi^+\nu\bar\nu$ to TeV scale charged Higgs boson.