Low-Multiplicity Jets as Probes of GeV-Scale Light-Quark-Coupled Particles

TL;DR

This paper proposes a novel LHC search strategy for GeV-scale light-quark-coupled particles using low-multiplicity jets, enhancing detection sensitivity in previously unexplored parameter space.

Contribution

It introduces a new search method based on low-multiplicity jets and data-driven background estimation for detecting light-quark-coupled particles at the LHC.

Findings

Sensitivity to scalar and pseudoscalar couplings to up-quarks is determined.

The method reduces uncertainties related to jet modeling.

The search extends the detection reach into previously inaccessible regimes.

Abstract

We propose a search at the LHC for GeV-scale particles coupling predominantly to light quarks based on low-multiplicity jets. The search targets production in association with a hard photon and uses the feature that a light gauge-singlet can only decay into a small number of hadronic channels, yielding jets with anomalously low charged-track multiplicity and mass compared to QCD jets at the same transverse momentum. We determine the sensitivity to scalar and pseudoscalar couplings to up-quarks, and suggest a data-driven estimate that reduces the sensitivity to jet modeling uncertainties. This search extends the reach to hadronically-coupled particles into a previously inaccessible regime.