On the $h \to V \ell^+ \ell^-$ decays

TL;DR

This paper analyzes specific Higgs boson decay modes into vector mesons and leptons within the Standard Model, providing decay rates, spectra, and helicity distributions, and explores implications for rare and flavor-changing decays.

Contribution

It offers the first detailed Standard Model predictions for $h o V \, \ell^+ \ell^-$ decays, including spectra and polarization, and examines related rare decay modes and flavor violation implications.

Findings

Calculated decay rates and spectra for $h \to V \ell^+ \ell^-$.

Determined the longitudinal helicity fractions of the vector mesons.

Discussed constraints on flavor-changing decays from LHC results.

Abstract

A set of exclusive decays of the Higgs boson into a vector meson and a dilepton pair ($h\to V \ell^+ \ell^-$, with $V=\Upsilon, J/\psi,\phi$, and $\ell=\mu, \tau$) are studied in the framework of the Standard Model. We have evaluated the decay rates, the dilepton mass spectra and the $V$ longitudinal helicity fraction distributions. In the same framework, we considered the exclusive modes $h\to V \nu \bar \nu$ and the implications of the CMS and ATLAS results for the lepton flavor-changing process $h\to \tau^+ \mu^-$ on the $h\to V \tau^+ \mu^-$ decay modes.