Stop-mass prediction in naturalness scenarios within MSSM-25

Abstract

The "top-down" approach to minimal supersymmetric standard model (MSSM) phenomenology provides model-dependent indications for a natural stop mass. The approach is based on specific assumptions about the supersymmetry-breaking energy scale and parameters degeneracies. In order to determine robust predictions we update the stop-mass prediction within the MSSM with 25 parameters (MSSM-25) by including electroweak fine-tuning as "naturalness data" during the Bayesian fits of the parameters to experimental data. The approximately prior-independent results show that imposing naturalness, taken here to mean a 25% to 100% fine-tuning, predicts a 1-2 TeV stop mass. The posterior distributions for the neutralino-proton cross sections indicate better prospects for probing the associated neutralino cold dark matter (CDM) with future upgrades of the detection facilities.