Constraining anomalous gluon self-interactions at the LHC: a reappraisal

TL;DR

This paper reassesses how well LHC measurements in various jet and heavy-quark processes can constrain anomalous gluon self-interactions described by dimension-six operators, emphasizing the robustness of multi-jet observables.

Contribution

It critically evaluates the sensitivity of LHC observables to the triple gluon operator and confirms multi-jet measurements as reliable bounds on these anomalous interactions.

Findings

Multi-jet observables can reliably constrain anomalous gluon interactions.

Higher order QCD corrections do not significantly affect bounds from multi-jet data.

Angular observables in three-jet events can further improve constraints.

Abstract

Anomalous self-interactions of non-abelian gauge fields can be described by higher dimensional operators featuring gauge-invariant combinations of the field strengths. In the case of QCD, the gluon self-interactions start to be modified at dimension six by operators of the type $GGG$, with $G$ the gluon field strength tensor, possibly leading to deviations in all observables and measurements that probe strong interactions at very small distances. In this work we consider the sensitivity to the triple gluon operator of a series of observables at the LHC in di-jet, three- and multi-jet final states and heavy-quark production. We critically re-examine the robustness of long-standing as well as more recent proposals addressing issues such as the validity of the EFT expansion and the impact of higher order QCD corrections. Our results support the conclusion that multi-jet observables can reliably bound these anomalous interactions to the level that their impact on other key observables at the LHC, involving for example top quark and Higgs production, can be safely neglected. We also highlight the potential of using previously suggested angular observables in three-jet events at the LHC to further constrain these interactions.