Probing top-Higgs non-standard interactions at the LHC

TL;DR

This paper investigates how non-standard top-Higgs interactions, especially the top quark chromomagnetic dipole moment, can be constrained and distinguished at the LHC through Higgs and top pair associated production measurements.

Contribution

It provides calculations of these operators' effects on Higgs and t tbar h production and highlights the potential of current and future measurements to constrain and differentiate them.

Findings

Current Higgs data already constrain these operators.

t tbar h production offers complementary information.

Differential rate measurements can discriminate among contributions.

Abstract

Effective interactions involving both the top quark and the Higgs field are among the least constrained of all possible (gauge invariant) dimension-six operators in the Standard Model. Such a handful of operators, in particular the top quark chromomagnetic dipole moment, might encapsulate signs of the new physics responsible for electroweak symmetry breaking. In this work, we compute the contributions of these operators to inclusive Higgs and t tbar h production. We argue that: i) rather strong constraints on the overall size of these operators can already be obtained from the current limits/evidence on Higgs production at the LHC; ii) t tbar h production will provide further key information that is complementary to t tbar measurements, and the possibility of discriminating among different contributions by performing accurate measurements of total and differential rates.