On Exclusive $h \to V \ell^+ \ell^-$ Decays

TL;DR

This paper investigates specific Higgs decay modes into vector mesons and leptons or neutrinos, analyzing decay rates, spectra, and helicity distributions, and discusses implications of recent experimental results on flavor-changing decays.

Contribution

It provides the first detailed analysis of exclusive $h o V \, \ell^+ \ell^-$ and $h \to V \nu \bar{\nu}$ decays, including decay rates and spectra, within the Standard Model framework.

Findings

Decay rates and spectra for $h\to V \ell^+ \ell^-$ modes are calculated.

Helicity fractions of the vector mesons are determined.

Implications for lepton flavor violation are discussed.

Abstract

We study a set of exclusive decay modes of the Standard Model Higgs boson into a vector meson and a dilepton pair: $h\to V \ell^+ \ell^-$, with $V=\Upsilon, J/\psi,\phi$, and $\ell=\mu, \tau$, determining the decay rates, the dilepton mass spectra and the $V$ longitudinal helicity fraction distributions. In the same framework, we analyze the exclusive modes into neutrino pairs $h\to V \nu \bar \nu$. We also discuss the implications of the recent CMS and ATLAS results for the lepton flavor-changing process $h\to \tau^+ \mu^-$ on the $h\to V \tau^+ \mu^-$ decay modes.