Dependence of the leptonic decays of H^- on the neutrino mixing angles theta_{13} and theta_{23} in models with neutrinophilic charged scalars

TL;DR

This paper investigates how the leptonic decays of the charged Higgs boson H^- depend on neutrino mixing angles theta_{13} and theta_{23} within models that link neutrino masses to a small vacuum expectation value, highlighting implications for neutrino oscillation parameters.

Contribution

It provides a quantitative analysis of how recent measurements of neutrino mixing angles influence the decay branching ratios of H^- in neutrinophilic models, connecting collider observables to neutrino oscillation parameters.

Findings

Decay ratios depend strongly on sin^2(2theta_{13}) and sin^2(theta_{23})

Measurement of H^- decays can inform on the neutrino mass ordering and CP phase

Branching ratios vary significantly with neutrino mixing angles and mass hierarchy

Abstract

In the Higgs Triplet Model and the neutrinophilic Two-Higgs-Doublet Model the observed neutrinos obtain mass from a vacuum expectation value which is much smaller than the vacuum expectation value of the Higgs boson in the Standard Model. Both models contain a singly charged Higgs boson (H^-) whose Yukawa coupling is directly related to the neutrino mass (i.e. a "neutrinophilic charged Higgs"). The partial decay widths of H^- into a charged lepton and a neutrino (H^- to l^- nu) depend identically on the neutrino masses and mixings in the two models. We quantify the impact of the recent measurement of sin^2(2theta_{13}), which plays a crucial role in determining the magnitude of the branching ratio of H^- to e^- nu for the case of a normal neutrino mass ordering if the lightest neutrino mass m_0 < 10^{-3} eV. We also discuss the sizeable dependence of H^- to mu^- nu and H^- to tau^- nu on sin^2(theta_{23}), which would enable information to be obtained on sin^2(theta_{23}) and the sign of \Delta m^2_{31} if these decays are measured. Such information would help neutrino oscillation experiments to determine the CP-violating phase \delta.