Not-so-inelastic Dark Matter

arXiv (Cornell University)

Abstract

Models of inelastic (or pseudo-Dirac) dark matter commonly assume an accidental symmetry between the left-handed and right-handed mass terms in order to suppress diagonal couplings. We point out that this symmetry is unnecessary, because for Majorana fermions the diagonal couplings are not strongly constrained. Removing the requirement of such an ad-hoc symmetry instead relaxes the relic density constraint due to additional annihilation modes. We consider a simple UV-complete model realising this setup and study constraints from (in)direct detection, beam dump experiments and colliders. We identify two viable mass regions for the dark matter mass, around a few hundred MeV and around a few GeV, respectively. The former region will be fully tested by near-future analyses of NA64 and Belle II data, while the latter turns out to be challenging to explore even with future experiments.

Authors 4

1. Giovani Dalla Valle Garcia
2. Felix Kahlhoefer

   Karlsruhe Institute of Technology

   Affiliation as printed

   Institute for Theoretical Particle Physics (TTP) , Karlsruhe Institute of Technology (KIT) , D-76131 Karlsruhe , Germany

3. Maksym Ovchynnikov Aachen Instituut-Lorentz

   Karlsruhe Institute of Technology · Leiden University

   Affiliation as printed

   Institut für Astroteilchen Physik , Karlsruher Institut für Technologie (KIT) , Hermann-von- Helmholtz-Platz 1 , 76344 Eggenstein-Leopoldshafen , Germany

   Instituut-Lorentz , Leiden University , Niels Bohrweg 2 , 2333 CA Leiden , The Netherlands

4. Thomas Schwetz

   Karlsruhe Institute of Technology

   Affiliation as printed

   Institut für Astroteilchen Physik , Karlsruher Institut für Technologie (KIT) , Hermann-von- Helmholtz-Platz 1 , 76344 Eggenstein-Leopoldshafen , Germany