Towards constraining triple gluon operators through tops

TL;DR

This paper investigates constraints on a CP-even gluonic operator using top-pair production at the LHC, finding significantly improved bounds on the new physics scale through cut-based and machine learning analyses.

Contribution

It provides the first detailed analysis of the CP-even gluonic operator's effects on top-pair production, establishing stronger bounds than previous studies.

Findings

New physics scale bound > 3.4 TeV at 95% C.L.

Stronger constraints than previous Run-I bounds.

Machine learning enhances sensitivity in the analysis.

Abstract

Effective field theory techniques provide us important tools to probe for physics beyond the Standard Model in a relatively model-independent way. In this work, we revisit the CP-even dimension-6 purely gluonic operator to investigate the possible constraints on it by studying its effect on top-pair production at the LHC, in particular the high $p_T$ and $m_{t\bar{t}}$ tails of the distribution. Cut-based analysis reveals that the scale of New Physics when this operator alone contributes to the production process is greater than 3.4 TeV at 95% C.L., which is a much stronger bound compared to the bound of 850 GeV obtained from Run-I data using the same channel. This is reinforced by an analysis using Machine Learning techniques. Our study complements similar studies that have focussed on other collider channels to study this operator.