MT2 to the Rescue -- Searching for Sleptons in Compressed Spectra at the LHC

TL;DR

This paper introduces a new method using the dilepton MT2 variable to detect sleptons in compressed spectra at the LHC, enabling potential discovery of sleptons up to 150 GeV mass.

Contribution

The study presents a novel approach employing the dilepton MT2 variable to improve slepton detection in compressed spectra at hadron colliders.

Findings

Sleptons up to 150 GeV can be discovered at the 14 TeV LHC.

The dilepton MT2 variable effectively suppresses backgrounds.

The method enhances sensitivity for compressed spectra searches.

Abstract

We propose a novel method for probing sleptons in compressed spectra at hadron colliders. The process under study is slepton pair production in R-parity conserving supersymmetry, where the slepton decays to a neutralino LSP of mass close to the slepton mass. In order to pass the trigger and obtain large missing energy, an energetic mono-jet is required. Both leptons need to be detected in order to suppress large standard model backgrounds with one charged lepton. We study variables that can be used to distinguish the signal from the remaining major backgrounds, which include tt, WW+jet, Z+jet, and single top production. We find that the dilepton MT2, bound by the mass difference, can be used as an upper bound to efficiently reduce the backgrounds. It is estimated that sleptons with masses up to about 150 GeV can be discovered at the 14 TeV LHC with 100/fb integrated luminosity.