Likelihood analysis of supersymmetric SU(5) GUTs

We perform a likelihood analysis of the constraints from accelerator experiments and astrophysical observations on supersymmetric (SUSY) models with SU(5) boundary conditions on soft SUSY-breaking parameters at the GUT scale. The parameter space of the models studied has seven parameters: a universal gaugino mass $$m_{1/2}$$m1/2, distinct masses for the scalar partners of matter fermions in five- and ten-dimensional representations of SU(5), $$m_5$$m5 and $$m_{10}$$m10, and for the $$\mathbf {5}$$5 and $${\bar{\mathbf{5}}}$$5¯ Higgs representations $$m_{H_u}$$mHu and $$m_{H_d}$$mHd, a universal trilinear soft SUSY-breaking parameter $$A_0$$A0, and the ratio of Higgs vevs $$\tan \beta $$tanβ. In addition to previous constraints from direct sparticle searches, low-energy and flavour observables, we incorporate constraints based on preliminary results from 13 TeV LHC searches for jets + events and long-lived particles, as well as the latest PandaX-II and LUX searches for direct Dark Matter detection. In addition to previously identified mechanisms for bringing the supersymmetric relic density into the range allowed by cosmology, we identify a novel $${\tilde{u}_R}/{\tilde{c}_R} - \tilde{\chi }^{0}_{1}$$u~R/c~R-χ~10 coannihilation mechanism that appears in the supersymmetric SU(5) GUT model and discuss the role of $${{\tilde{\nu }}_\tau }$$ν~τ coannihilation. We find complementarity between the prospects for direct Dark Matter detection and SUSY searches at the LHC.