Likelihood analysis of the sub-GUT MSSM in light of LHC 13-TeV data

We describe a likelihood analysis using MasterCode of variants of the MSSM in which the soft supersymmetry-breaking parameters are assumed to have universal values at some scale Min below the supersymmetric grand unification scale MGUT, as can occur in mirage mediation and other models. In addition to Min, such ‘sub-GUT’ models have the 4 parameters of the CMSSM, namely a common gaugino mass m1 / 2, a common soft supersymmetry-breaking scalar mass m0, a common trilinear mixing parameter A and the ratio of MSSM Higgs vevs tan β, assuming that the Higgs mixing parameter μ> 0. We take into account constraints on strongly- and electroweakly-interacting sparticles from ∼ 36 /fb of LHC data at 13 TeV and the LUX and 2017 PICO, XENON1T and PandaX-II searches for dark matter scattering, in addition to the previous LHC and dark matter constraints as well as full sets of flavour and electroweak constraints. We find a preference for Min∼ 10 5 to 109GeV, with Min∼ MGUT disfavoured by Δ χ2∼ 3 due to the BR (Bs , d→ μ+μ-) constraint. The lower limits on strongly-interacting sparticles are largely determined by LHC searches, and similar to those in the CMSSM. We find a preference for the LSP to be a Bino or Higgsino with mχ~10∼1TeV, with annihilation via heavy Higgs bosons H / A and stop coannihilation, or chargino coannihilation, bringing the cold dark matter density into the cosmological range. We find that spin-independent dark matter scattering is likely to be within reach of the planned LUX-Zeplin and XENONnT experiments. We probe the impact of the (g- 2) μ constraint, finding similar results whether or not it is included.