Decoding the gaugino code, naturally, at high-lumi LHC

Abstract

Natural supersymmetry with light higgsinos is most likely to emerge from the string landscape since the volume of scan parameter space shrinks to tiny volumes for electroweak unnatural models. Rather general arguments favor a landscape selection of soft SUSY breaking terms tilted to large values, but tempered by the atomic principle: that the derived value of the weak scale in each pocket universe lie not too far from its measured value in our universe. But that leaves (at least) three different paradigms for gaugino masses in natural SUSY models: unified (as in nonuniversal Higgs models), anomaly-mediation form (as in natural AMSB) and mirage mediation form (with comparable moduli- and anomaly-mediated contributions). We perform landscape scans for each of these, and show they populate different, but overlapping, positions in m(\ell\bar{\ell}) and m(wino) space. The first of these may be directly measurable at high-lumi LHC via the soft opposite-sign dilepton plus jets plus MET signature arising from higgsino pair production while the second of these could be extracted from direct wino pair production leading to same-sign diboson production.