Jet Substructure by Accident

TL;DR

This paper introduces a novel search strategy for high-multiplicity hadronic events that leverages accidental jet substructure, enhancing background discrimination without relying on missing energy, and demonstrates its effectiveness in R-parity violating gluino decay searches.

Contribution

It proposes using accidental jet substructure as a new discriminant for high-multiplicity signals, enabling data-driven background estimation without missing energy reliance.

Findings

Accidental substructure is more pronounced in high-multiplicity signals.

The method improves background suppression in multi-jet searches.

Expected limits are demonstrated for R-parity violating gluino decays.

Abstract

We propose a new search strategy for high-multiplicity hadronic final states. When new particles are produced at threshold, the distribution of their decay products is approximately isotropic. If there are many partons in the final state, it is likely that several will be clustered into the same large-radius jet. The resulting jet exhibits substructure, even though the parent states are not boosted. This "accidental" substructure is a powerful discriminant against background because it is more pronounced for high-multiplicity signals than for QCD multijets. We demonstrate how to take advantage of accidental substructure to reduce backgrounds without relying on the presence of missing energy. As an example, we present the expected limits for several R-parity violating gluino decay topologies. This approach allows for the determination of QCD backgrounds using data-driven methods, which is crucial for the feasibility of any search that targets signatures with many jets and suppressed missing energy.