Searching for New Physics in the Three-Body Decays of the Higgs-like Particle

TL;DR

This paper explores how detailed analysis of three-body Higgs-like particle decays at the LHC can reveal signs of new physics beyond the Standard Model, even when overall decay rates appear standard.

Contribution

It demonstrates the potential of differential decay width analysis to uncover new physics effects in Higgs-like particle decays that are hidden in integrated decay measurements.

Findings

Differential decay widths can reveal new physics effects.

Certain phase space regions are especially sensitive to new physics.

Standard Model consistency does not preclude detectable new physics signals.

Abstract

We show that the three-body decays of the resonance recently discovered at the LHC are potentially sensitive to effects of new physics. Even if the fully integrated partial decay widths are consistent with the minimal Standard Model there is information that is lost upon integration, which can be uncovered in the differential decay widths. Concentrating on the decay $h \to Z \ell \bar{\ell}$, we identify the regions in the three-body phase space in which these effects become especially pronounced and could be detected in future experiments.