A New Observable for Identifying Dijet Resonances

TL;DR

This paper introduces a new observable that improves the identification of dijet resonances at the LHC, effectively reducing background noise and enhancing sensitivity for both SM measurements and new physics searches, especially under systematic uncertainties.

Contribution

The paper proposes a novel observable for dijet resonance identification that remains effective across various boosts and reduces background significantly.

Findings

Background reduced by a factor of 3-5

Signal efficiency of 10-20%

Applicable across different processes and boost levels

Abstract

The development of techniques for identifying hadronic signals from the overwhelming multi-jet backgrounds is an important part of the Large Hadron Collider (LHC) program. Of prime importance are resonances decaying into a pair of partons, such as the Higgs and $\rm W$/$\rm Z$ bosons, as well as hypothetical new particles. We present a simple observable to help discriminate a dijet resonance from background that is effective even when the decaying resonance is not strongly boosted. We find consistent performance of the observable over a variety of processes and degree of boosts, and show that it leads to a reduction of the background by a factor of $3-5$ relative to signal at the price of $10-20\%$ signal efficiency. This approach represents a significant increase in sensitivity for Standard Model (SM) measurements and searches for new physics that are dominated by systematic uncertainties, which is true of many analyses involving jets - particularly in the high-luminosity running of the LHC.