Off-shell Higgs signal and total width determination at the LHC

TL;DR

This paper reviews a novel method using off-shell Higgs signals in LHC data to constrain the Higgs boson's total width, offering a complementary approach to traditional measurements.

Contribution

It introduces and discusses the theoretical foundation of a new approach to determine the Higgs width via off-shell signals, enhancing existing measurement techniques.

Findings

LHC experiments set upper bounds on Higgs width using off-shell signals.

Theoretical basis supports the complementarity of this method.

Potential for improved constraints at future colliders.

Abstract

A substantial off-shell Higgs boson signal in the gluon fusion and vector boson fusion H --> ZZ and H --> WW channels at the Large Hadron Collider (LHC) facilitates a novel, complementary approach to constraining the total Higgs width Gamma_H. With LHC Run 1 data, experimental analyses by CMS and ATLAS find Gamma_H < 5.4 Gamma_H,SM and Gamma_H < [4.5,7.5] Gamma_H,SM at 95% confidence level, respectively, where Gamma_H,SM is the expected value in the Standard Model at the measured Higgs boson mass. I review the theoretical basis of the new approach and discuss its significance in comparison to other methods to bound and measure the Higgs width at the LHC and future colliders.