LHC Constraints on NLSP Gluino and Dark Matter Neutralino in Yukawa Unified Models

TL;DR

This paper uses ATLAS data to constrain supersymmetric models with a gluino NLSP nearly degenerate with a neutralino LSP, finding that gluino masses below about 300 GeV are excluded and that LHC constraints can surpass other dark matter detection bounds.

Contribution

It provides new constraints on Yukawa unified supersymmetric models with NLSP gluino and neutralino LSP using recent LHC data, surpassing some direct and indirect detection limits.

Findings

Gluino NLSP masses below ~300 GeV are excluded.

LHC constraints on neutralino-nucleon cross sections can be more stringent than IceCube and Xenon1T.

Constraints depend on the sign of the MSSM ta parameter.

Abstract

The ATLAS experiment has recently presented its search results for final states containing jets and/or b-jet(s) and missing transverse momentum, corresponding to an integrated luminosity of 165 pb^{-1}. We employ this data to constrain a class of supersymmetric SU(4)_c X SU(2)_L X SU(2)_R models with t-b-\tau Yukawa unification, in which the gluino is the next to lightest supersymmetric particle (NLSP). The NLSP gluino is slightly (~10-30%) heavier than the the LSP dark matter neutralino, and it primarily decays into the latter and a quark-antiquark pair or gluon. We find that NLSP gluino masses below ~300 GeV are excluded by the ATLAS data. For LSP neutralino mass ~200-300 GeV and \mu>0, where \mu is the coefficient of the MSSM Higgs bilinear term, the LHC constraints in some cases on the spin-dependent (spin-independent) neutralino-nucleon cross section are significantly more stringent than the expected bounds from IceCube DeepCore (Xenon 1T/SuperCDMS). For \mu<0, this also holds for the spin-dependent cross sections.