Sneutrino dark matter in gauged inverse seesaw models for neutrinos

Explaining the XENON1T Excess with Luminous Dark Matter

We show that the excess in electron recoil events seen by the XENON1T experiment can be explained by a relatively low-mass luminous dark matter candidate. The dark matter scatters inelastically in the detector (or the surrounding rock) to produce a heavier dark state with a ∼2-3  keV mass splitting. This heavier state then decays within the detector, producing a peak in the electron recoil spectrum that is a good fit to the observed excess. We comment on the ability of future direct detection experiments to differentiate this model from other "beyond the standard model" scenarios and from possible tritium backgrounds, including the use of diurnal modulation, multichannel signals, etc., as possible distinguishing features of this scenario.

New Physics Opportunities in the Boosted Di-Higgs-Boson Plus Missing Transverse Energy Signature

The Higgs field in the standard model may couple to new physics sectors related to dark matter and/or massive neutrinos. In this Letter we propose a novel signature, the boosted di-Higgs-boson plus E_{T} (which is either a dark matter or neutrino), to probe those new physics sectors. In a large class of models, in particular, the supersymmetric standard models and low scale seesaw mechanisms, this signature can play a key role. The signature has a clear background, and at the sqrt[s]=14  TeV high luminosity LHC, we can probe it with a production rate as low as ∼0.1  fb. We apply it to benchmark models, supersymmetry in the bino-Higgsino limit, the canonical seesaw model, and the little Higgs model, finding that the masses of the Higgsino, right-handed neutrino, and heavy vector boson can be probed up to ∼500, 650, and 900 GeV, respectively.