Higgs couplings: disentangling New Physics with off-shell measurements

TL;DR

This paper explores how off-shell measurements of Higgs-related processes can provide a more model-independent way to analyze Higgs couplings and potential new physics, beyond traditional on-shell methods.

Contribution

It demonstrates that off-shell measurements can be interpreted in a model-independent manner to study Higgs couplings and constrain new physics.

Findings

Off-shell measurements offer a model-independent approach.

Current CMS results can be reinterpreted beyond width constraints.

Off-shell data can disentangle Higgs couplings from new physics effects.

Abstract

After the discovery of a scalar resonance, resembling the Higgs boson, its couplings have been extensively studied via the measurement of various production and decay channels on the invariant mass peak. Recently, it has been suggested the possibility to use off-shell measurements: in particular, CMS has published results based on the high- invariant mass cross section of the process $gg \to ZZ$, which contains the contribution of the Higgs. While this measurement has been interpreted as a constraint on the Higgs width after very specific assumptions are taken on the Higgs couplings, in this letter we show that a much more model-independent interpretation is possible.