Matched predictions for Higgs production via heavy-quark loops in the SM and beyond

TL;DR

This paper presents a fully exclusive simulation of Higgs production via gluon fusion, including heavy-quark loop effects, and compares standard model and b-philic Higgs scenarios, demonstrating the importance of exact loop calculations for accurate kinematic predictions.

Contribution

It introduces a matched simulation framework for Higgs production that incorporates full heavy-quark loop dependence, improving accuracy over previous approximations.

Findings

Matched samples accurately describe final state kinematics.

Large heavy-quark-mass approximation is valid for the SM Higgs at most pT.

Exact loop calculations are crucial for b-philic Higgs scenarios.

Abstract

The main Higgs production channel at hadron colliders is gluon fusion via heavy-quark loops. We present the results of a fully exclusive simulation of gluon fusion Higgs production based on the matrix elements for h + 0, 1, 2 partons including full heavy-quark loop dependence, matched to a parton shower. We consider a Higgs with standard model couplings as well as models where the Higgs has enhanced couplings to bottom quarks (b-philic). We study the most relevant kinematic distributions, such as jet and Higgs pT spectra and find that matched samples provide an accurate description of the final state. For the SM Higgs, we confirm the excellent accuracy of the large heavy-quark-mass approximation also in differential distributions over all phase space, with significant effects arising only at large pT . For a b-philic Higgs however, the loops have a dramatic impact on the kinematics of the Higgs as well as of the jets and need to be accounted for exactly to achieve reliable event simulations.