On resonance search in dilepton events at the LHC

TL;DR

This paper proposes a new method to improve resonance searches in dilepton events at the LHC by optimizing cuts based on pseudorapidity differences, aiding in distinguishing excited bosons from Standard Model backgrounds.

Contribution

It introduces a novel cut optimization technique leveraging the Delta_eta distribution to enhance the detection of excited bosons in dilepton invariant mass spectra.

Findings

Excited bosons produce a peak at Delta_eta = 1.76.

Optimized cuts increase the significance of resonance signals.

Additional angular distributions are necessary for confirmation.

Abstract

The main distribution for a bump search is the dilepton invariant mass distribution with appropriated cut on an absolute value of pseudorapidity difference Delta_eta = |eta_1 - eta_2| between the two leptons. The background from the Standard Model Drell-Yan process contributes mainly to the central pseudorapidity region Delta_eta = 0. By contrast, the excited bosons lead to a peak at Delta_eta = 1.76. We show that this property allows to enhance the significance of their bump search by means of new cut optimization. Nevertheless, in order to confirm an observation of the bump and reveal the resonance nature other angular distributions should be used in addition.