Geolocating the Higgs Boson Candidate at the LHC

TL;DR

This paper discusses the detailed measurement and characterization of the Higgs boson candidate at the LHC, focusing on its properties and couplings through various decay channels, and introduces a parametrization of its coupling degrees of freedom.

Contribution

It introduces a comprehensive framework for analyzing the Higgs boson's properties using decay channels and proposes a novel parametrization of its coupling degrees of freedom.

Findings

Constraints on Higgs couplings derived from decay rates

A new parametrization of Higgs coupling degrees of freedom

Disfavoring of certain alternative hypotheses for the resonance

Abstract

The latest results from the ATLAS and CMS experiments at the CERN Large Hadron Collider (LHC) unequivocally confirm the existence of a resonance, $X$, with mass near 125 GeV which could be the Higgs boson of the Standard Model. Measuring the properties (quantum numbers and couplings) of this resonance is of paramount importance. Initial analyses by the LHC collaborations disfavor specific alternative benchmark hypotheses, e.g. pure pseudoscalars or gravitons. However, this is just the first step in a long-term program of detailed measurements. We consider the most general set of operators in the decay channels $X \to ZZ$, $WW$, $Z\gamma$, $\gamma\gamma$ and derive the constraint implied by the measured rate. This allows us to provide a useful parametrization of the orthogonal independent Higgs coupling degrees of freedom as coordinates on a suitably defined sphere.