Effect of anomalous $HHH$ coupling on the decay $H\rightarrow Z\,Z^*\rightarrow$ 4 charged leptons

TL;DR

This paper calculates electroweak corrections to Higgs decay into four leptons, considering anomalous triple Higgs coupling effects, which can help constrain the Higgs potential structure.

Contribution

It provides the first gauge-invariant computation of electroweak corrections including anomalous $HHH$ coupling effects in Higgs decay to four leptons.

Findings

Corrections are about 1.26% for $H o e^+ e^- \mu^+ \mu^-$ in the $G_F$ scheme.

Corrections vary from less than 1% to -6% when changing the $\kappa$ parameter from 4 to -4.

Large corrections can be used to bound the $HHH$ coupling and understand Higgs potential.

Abstract

We have computed the electroweak corrections to $H\rightarrow Z\,Z^*\rightarrow$ 4 charged leptons, including the effect of anomalous $HHH$ coupling in the $\kappa$-framework. The results of this scaling are gauge invariant. We have computed the results for $ H \to e^+ e^- \mu^+ \mu^-$ and $ H \to e^+ e^- e^+ e^-$ processes. The corrections for the both processes depend on the input parameter scheme. In the $G_F$ scheme, the electroweak corrections are about $1.26\%$ for the $ H \to e^+ e^- \mu^+ \mu^-$ and about $0.25\%$ for the $ H \to e^+ e^- e^+ e^-$ process. However changing the $\kappa$ from $4$ to $-4$, the corrections vary from less than $1\%$ to about $-6\%$. We have plotted a number of kinematic distributions. The corrections over most of the phase space regions are similar. These large corrections can be used to put a bound on the $HHH$ coupling. This can help in determining the structure of the Higgs potential.