Minding the gap: Testing natural anomaly-mediated SUSY breaking at high luminosity LHC
Howard Baer (Department of Physics and Astronomy, University of Oklahoma, Norman, Oklahoma 73019, USA); Vernon Barger (Department of Physics, University of Wisconsin, Madison, Wisconsin 53706, USA); Jessica Bolich (Department of Physics and Astronomy, University of Oklahoma, Norman, Oklahoma 73019, USA); Juhi Dutta (Department of Physics and Astronomy, University of Oklahoma, Norman, Oklahoma 73019, USA); Dibyashree Sengupta (INFN, Laboratori Nazionali di Frascati, Via Enrico Fermi 54, 00044 Frascati (ROME), Italy)
While the minimal anomaly-mediated SUSY breaking model (mAMSB) seems ruled out by constraints on Higgs mass, naturalness and wino dark matter, a slightly generalized version dubbed natural AMSB (nAMSB) remains both viable and compelling. Like mAMSB, nAMSB features winos as the lightest gauginos, but unlike mAMSB, nAMSB allows a small parameter so that Higgsinos are the lightest of electroweakinos (EWinos). nAMSB spectra depend on the input value of gravitino mass , where the lower range of is excluded by LHC gluino pair searches while a higher band is excluded by LHC limits on wino pair production followed by boosted hadronic wino decays. A remaining intermediate gap in values remains allowed by present LHC searches, but appears to be completely explorable by high luminosity upgrades of LHC (HL-LHC). We explore a variety of compelling discovery channels that may allow one to close the intermediate gap in values: (1) same-sign (SSdB) production arising from wino pair production, leading to same-sign dileptons plus missing , (2) trilepton production arising from wino pair production and (3) soft dilepton plus jet events from Higgsino pair production, (4) top-squark pair production. From our signal-to-background analysis along a nAMSB model line, we expect HL-LHC to either discover or rule out the nAMSB model with of integrated luminosity.