New charged Higgs effects on $\Gamma_{K_{e2}}/\Gamma_{K_{\mu 2}}$, $f_{D_s}$ and ${\cal B}(B^+\to \tau^+ \nu)$ in the Two-Higgs-Doublet model

TL;DR

This paper introduces a novel Yukawa matrix scheme in the two-Higgs-doublet model that allows for flavor-dependent charged Higgs effects, impacting kaon decay ratios, D_s decay constants, and B meson leptonic decay branching ratios.

Contribution

It proposes a new Yukawa matrix framework in THDM that naturally incorporates flavor-dependent charged Higgs couplings with CP phases, avoiding FCNCs without symmetry constraints.

Findings

Charged Higgs effects influence kaon decay ratios and cannot be eliminated.

D_s decay constant can be enhanced by charged Higgs contributions.

Branching ratio for B+ to tau+ nu can be significantly increased.

Abstract

A new scheme for Yukawa matrices is proposed for free of flavor changing neutral currents (FCNCs) at tree level in general two-Higgs-doublet model (THDM) without imposing symmetry. We find that the new type couplings of charged Higgs to fermions not only depend on the flavors, but also can be ascribed by new CP violating phases. Unlike conventional THDM, the resulted new charged Higgs effects could have the specialties: (a) the influence on $\Gamma(K^\pm_{e 2})/\Gamma(K^\pm_{\mu 2})$ cannot be eliminated, (b) the decay constant of $D_s$ could be enhanced, and (c) enhancement of branching ratio for $B^+\to \tau^+ \nu$ could be achieved.