Self-interacting dark matter and cosmology of a light scalar mediator
Kainulainen, K., Tuominen, K., & Vaskonen, V. (2016). Self-interacting dark matter and cosmology of a light scalar mediator. Physical Review D, 93 (1), 015016. doi:10.1103/PhysRevD.93.015016
Published inPhysical Review D
© 2016 American Physical Society. Published in this repository with the kind permission of the publisher.
We consider a fermionic dark matter candidate interacting via a scalar mediator coupled with the Standard Model through a Higgs portal. We consider a general setting including both scalar and pseudoscalar interactions between the scalar and fermion, and illustrate the relevant features for dark matter abundance, direct search limits and collider constraints. The case where dark matter has a self-interaction strength hσVi=mψ ∼ 0.1–1 cm2=g is strongly constrained, in particular by the big bang nucleosynthesis. We show that these constraints can be alleviated by introducing a new light sterile neutrino N. The allowed region for the extended model consists of two triangles as a function of the mass mN and a sufficiently small sterile-active neutrino mixing angle sin θ < 0.007: first 10ðsin θÞ−2=5 MeV ≲ mN ≲ 1 GeV and second 15ðsin θÞ−2=5 keV ≲ mN ≲ 1 MeV.