Sneaky Sneutrino Scattering at LZ

Abstract

We explore a model of sneutrino dark matter in the Minimal R-Symmetric Supersymmetric Standard Model as a possible interpretation of the recent event at LZ with high reconstructed nuclear recoil energy. This model can account for a small mass splitting between neutral states in a technically natural way due to terms which violate lepton number; importantly, this model does not require sending masses of other SUSY particles to an extremely high energy scale. Mixing with additional singlet states suppresses the interaction strength with standard model particles which allows the sneutrino to sneak around bounds obtained from searches for annihilating dark matter captured in the sun and allows the dark matter to remain near the TeV scale and still potentially account for the LZ results. Typically, sneutrinos produce too much dark matter unless they are very light; we consider a minimal scenario where production occurs through co-annihilation as one specific mechanism where the dark matter mass is predicted to be around $360$ GeV.