Quark-gluon discrimination in the search for gluino pair production at the LHC

TL;DR

This paper demonstrates that incorporating quark-gluon jet discrimination significantly enhances the LHC's ability to detect gluino pairs, especially at intermediate mass gaps, by improving signal-background separation.

Contribution

It introduces the use of jet substructure observables for quark-gluon discrimination in gluino searches, showing improved sensitivity over standard methods.

Findings

Jet substructure observables improve search reach for gluino pairs.

Quark-gluon separation is most impactful at intermediate mass gaps.

Uncertainty from Monte Carlo modeling is assessed.

Abstract

We study the impact of including quark- and gluon-initiated jet discrimination in the search for strongly interacting supersymmetric particles at the LHC. Taking the example of gluino pair production, considerable improvement is observed in the LHC search reach on including the jet substructure observables to the standard kinematic variables within a multivariate analysis. In particular, quark and gluon jet separation has higher impact in the region of intermediate mass-gap between the gluino and the lightest neutralino, as the difference between the signal and the standard model background kinematic distributions is reduced in this region. We also compare the predictions from different Monte Carlo event generators to estimate the uncertainty originating from the modelling of the parton shower and hadronization processes.