Boosting low-mass hadronic resonances

TL;DR

This paper proposes a novel method to search for low-mass hadronic resonances at the LHC by leveraging boosted kinematics against high-$p_T$ probes, enhancing sensitivity in a previously challenging mass range.

Contribution

It introduces a new search strategy for low-mass hadronic resonances using boosted techniques with existing LHC data, improving detection prospects for quark-coupled $Z'$ models.

Findings

Existing 2015 LHC data can detect $Z'$ resonances from 20 to 500 GeV/c$^2$.

Boosted reconstruction techniques increase sensitivity to low-mass resonances.

The method is effective against QCD backgrounds in the low-mass region.

Abstract

Searches for new hadronic resonances typically focus on high-mass spectra, due to overwhelming QCD backgrounds and detector trigger rates. We present a study of searches for relatively low-mass hadronic resonances at the LHC in the case that the resonance is boosted by recoiling against a well-measured high-$p_{\textrm{T}}$ probe such as a muon, photon or jet. The hadronic decay of the resonance is then reconstructed either as a single large-radius jet or as a resolved pair of standard narrow-radius jets, balanced in transverse momentum to the probe. We show that the existing 2015 LHC dataset of $pp$ collisions with $\int\mathcal{L}dt = 4\ \mathrm{fb}^{-1}$ should already have powerful sensitivity to a generic $Z'$ model which couples only to quarks, for $Z'$ masses ranging from 20-500 GeV/c$^2$.