Gravitino dark matter in split supersymmetry with bilinear R-parity violation

Abstract

In Split-SUSY with BRpV we show that the Gravitino DM solution is consistent with experimental evidence as regards its relic density and life time. We arrive at this conclusion by performing a complete numerical and algebraic study of the parameter space, including constraints from the recently determined Higgs mass, updated neutrino physics, and BBN constraints on NLSP decays. The Higgs mass requires a relatively low Split-SUSY mass scale, which is naturally smaller than usual values for reheating temperature, allowing the use of the standard expression for the relic density. We include restrictions from neutrino physics with three generations, and we notice that the gravitino decay width depends on the atmospheric neutrino mass scale. We calculate the neutralino decay rate and find it consistent with BBN. We mention some implications on indirect DM searches.

Search for sharp and smooth spectral signatures of μνSSM gravitino dark matter with Fermi-LAT

“…However, gravitino decays through off-shell particles into three-body final states, produces a smooth spectrum of energetic γ-rays that could also be observed at Fermi -LAT, as pointed out in refs. [16][17][18]23]. In this paper we perform a deep exploration of the µνSSM parameter space updating previous constraints, and paying special attention to regions where the gravitino decays with a sizable branching ratio (BR) into three-body final states, while suppressing the monochromatic photon signal.…”

Same-sign trileptons as a signal of sneutrino lightest supersymmetric particle

“…Therefore, physicists not only ponder on possible discovery channels for SUSY at the Large Hadron Collider (LHC), [1,2] but also wish to know how, if discovered, we can identify the lightest SUSY particle (LSP) which is the DM candidate. In the minimal SUSY standard model (MSSM) or its immediate extensions, the DM candidate [3] usually is χ 0 1 , the lightest neutralino (a linear superposition of the 'partners' of the photon, the Zboson and the neutral Higgs-like spinless particles), the gravitino (partner of the graviton) [4,5], or the axino (partner of an axion) [6,7]. The signals at the LHC are dominantly jets with missing transverse energy (MET) [8,9] occasionally with leptons and/or photons alongside.…”