pp -> ttH, H->tau tau: toward a model independent determination of the Higgs boson couplings at the LHC

TL;DR

This work assesses the LHC’s ability to determine Higgs boson couplings in a model-independent way, focusing on the pp -> t t̄ H with H -> ττ channel as a key addition to the Higgs coupling program. It develops a framework that links production and decay observables to Higgs partial widths via Z^(i)_j quantities and treats loop-induced couplings (Hgg, Hγγ) as potentially including non-SM contributions. Through a detailed LO study of ttH with H -> ττ for M_H ≤ 140 GeV, and by integrating this channel into a broader set of channels, the authors show that one can extract individual widths and several coupling ratios with roughly 7–25% precision, and 20–30% for certain ratios, enabling a largely model-independent determination of the Higgs couplings at the LHC. The approach remains less capable of a fully model-independent extraction for M_H > 140 GeV, but provides a concrete method to test coupling universality and probe new physics in loop-induced processes with high luminosity.

Abstract

The possibility of detecting a Higgs boson through several production and decay channels is instrumental to the measurement of its couplings. In this paper we study the pp-> ttH(H-> tau tau) channel at the LHC, for the case of a scalar Higgs boson, and use the obtained results to improve on existing strategies toward a model independent determination of the Higgs boson couplings. The case of a scalar Higgs boson with mass below 140 GeV looks particularly promising.