Hide and Seek With Natural Supersymmetry at the LHC

TL;DR

This paper proposes a new search strategy for supersymmetric gluinos at the LHC that evade traditional missing transverse momentum signatures, focusing on same-sign leptons resulting from R-parity violating decays, and sets a lower mass bound of 550 GeV.

Contribution

It introduces a novel approach to detect natural supersymmetry scenarios hidden from previous searches by focusing on specific decay signatures involving same-sign leptons.

Findings

Existing 2011 searches exclude gluinos below 550 GeV in certain R-parity violating scenarios.

Natural supersymmetry can evade traditional missing energy signatures, requiring alternative search strategies.

Proposes targeted LHC searches for gluinos decaying via baryon number violation with masses below 1 TeV.

Abstract

Gluinos that result in classic large missing transverse momentum signatures at the LHC have been excluded by 2011 searches if they are lighter than around 800 GeV. This adds to the tension between experiment and supersymmetric solutions of the naturalness problem, since the gluino is required to be light if the electroweak scale is to be natural. Here, we examine natural scenarios where supersymmetry is present, but was hidden from 2011 searches due to violation of R-parity and the absence of a large missing transverse momentum signature. Naturalness suggests that third generation states should dominate gluino decays and we argue that this leads to a generic signature in the form of same-sign, flavour-ambivalent leptons, without large missing transverse momentum. As a result, searches in this channel are able to cover a broad range of scenarios with some generality and one should seek gluinos that decay in this way with masses below a TeV. We encourage the LHC experiments to tailor a search for supersymmetry in this form. We consider a specific case that is good at hiding: baryon number violation, and estimate that the most constraining existing search from 2011 data implies a lower bound on the gluino mass of 550 GeV.