A note on the rare decay of a Higgs boson into photons and a $Z$ boson

Abstract

We have calculated the width of the rare decay $H\to \gamma \gamma Z$ at one-loop level in the standard model for Higgs boson masses in the range $115\mathrm{GeV}\le m_H\le 160\mathrm{GeV}$ . For this range of Higgs boson masses we find that $Z$ boson is predominantly longitudinally polarized, and the photons have the same helicity. A comparison of the decay width $\Gamma (H\to \gamma \gamma Z)$ to those of $H\to \gamma \gamma$ and $H\to \gamma Z$ shows that, for the Higgs boson mass of $m_H\sim 135\mathrm{GeV}$, the ratios of the decay widths are $\Gamma (H\to \gamma \gamma Z)/\Gamma (H\to \gamma \gamma )\sim \Gamma (H\to \gamma \gamma Z)/\Gamma (H\to \gamma Z)\sim 10^{-5}-10^{-6}$.

Comments: 4 pages, 5 figures, RevTeX