Detecting light stop pairs in coannihilation scenarios at the LHC

TL;DR

This paper investigates the potential of the LHC to detect light stop pairs in three coannihilation scenarios relevant for dark matter, proposing specific search strategies and estimating exclusion limits based on current and future data.

Contribution

It introduces search strategies for light stop pairs in coannihilation scenarios at the LHC and estimates exclusion limits for stop masses with existing and projected datasets.

Findings

LHC at 7 TeV with 5 fb^{-1} can exclude stop masses up to 220-380 GeV.

LHC at 8 TeV with 20 fb^{-1} can exclude stop masses up to 340-430 GeV.

Different coannihilation scenarios require distinct detection signatures.

Abstract

In this work, we study the light stop pair signals at the large hadron collider (LHC) in three coannihilation scenarios. In order to yield the desired dark matter (DM) relic density, the neutralino can coannihilate with stop, chargino and stau, respectively. Signatures of the first scenario can be probed at the LHC via the associated jet production processes $pp \to j + {\tilde t} {\tilde t}^*$ by tagging an energetic mono-jet and a large missing transverse energy. The signatures of the other two scenarios can be searched via the pair production process $pp \to {\tilde t} {\tilde t}^*$ by tagging energetic b-jets in the final states and a large missing transverse energy. We find that the LHC results at 7 TeV with 5 $\mathrm{fb}^{-1}$ of data can exclude the stop mass up to 220, 380 and 220 GeV for these three scenarios, respectively. While the 20 $\mathrm{fb}^{-1}$ dataset at 8 TeV is considered, the LHC can be expected to exclude the stop mass up to 340, 430 and 370 GeV.