Implications of Yukawa Textures in the decay $H^+ \to W^+ \gamma$ within the 2HDM-III

TL;DR

This paper explores how a specific Yukawa texture affects the decay of charged Higgs bosons into W gamma within the 2HDM-III, showing potential for significant enhancement and implications for LHC detection.

Contribution

It provides a detailed analysis of charged Higgs couplings, decay enhancements, and production rates in the 2HDM-III, considering experimental constraints and collider phenomenology.

Findings

Branching ratio of $H^+ o W^+ \gamma$ can reach ~0.1 for 180 GeV Higgs.

Charged Higgs production rates are estimated at the LHC, with significant event numbers.

Decay and production channels are compatible with current experimental bounds.

Abstract

We discuss the implications of assuming a four-zero Yukawa texture for the charged Higgs decay $H^+ \to W^+ \gamma$ at one-loop level, within the context of the general 2-Higgs Doublet Model of Type III. We begin by presenting a detailed analysis of the charged Higgs boson couplings with heavy quarks and the resulting effects on its decays. In particular, we present the possible enhancement of the decay $H^+ \to W^+ \gamma$, whose branching ratio could be of the order $\sim 10^{-1}$, for charged Higgs mass of the order 180 GeV. These parameters can still avoid the $B \to X_s \gamma$ constraint and the perturbativity bound. The production of charged Higgs bosons is also sensitive to the modifications of its couplings, and we evaluate the events rates at the LHC, including the `direct' $c\bar{b}\to H^++c. c.$ and `indirect' $q\bar q, gg \to \bar t b H^++c. c.$ production channels. We get an event rate of order 60 (120) for `direct' (`indirect') production reaction, and including decay $H^+ \to W^+ \gamma $ in the final state, with an integrated luminosity of $10^5$ $pb^{-1}$.