Abstract
Self-interacting dark matter (SIDM) is a simple and well-motivated scenario that could explain long-standing puzzles in structure formation on small scales. If the required self-interaction arises through a light mediator (with mass ∼ 10 MeV) in the dark sector, this new particle must be unstable to avoid overclosing the universe. The decay of the light mediator could happen due to a weak coupling of the hidden and visible sectors, providing new signatures for direct detection experiments. The SIDM nuclear recoil spectrum is more peaked towards low energies compared to the usual case of contact interactions, because the mediator mass is comparable to the momentum transfer of nuclear recoils. We show that the SIDM signal could be distinguished from that of DM particles with contact interactions by considering the time-average energy spectrum in experiments employing different target materials, or the average and modulated spectra in a single experiment. Using current limits from LUX and SuperCDMS, we also derive strong bounds on the mixing parameter between hidden and visible sector.
Highlights
Dark matter (DM) accounts for 85% of the matter in the universe [1], but its particle physics nature remains elusive
A compelling possibility is that DM may strongly interact with itself [4]
We study the Self-interacting dark matter (SIDM) event spectrum in the light of SuperCDMS, LUX, and DAMA, taking into account realistic efficiency and energy resolution of the detectors. Considering both the time-average and modulated event rates, we show that direct detection experiments can potentially distinguish SIDM from weakly interacting massive particle (WIMP)
Summary
Dark matter (DM) accounts for 85% of the matter in the universe [1], but its particle physics nature remains elusive. The DM densities inferred in the central regions of DMdominated galaxies are, on average, lower than expected from DM-only simulations [2, 3] Given this situation and the lack of a consistent signal in WIMP searches, it is important to thoroughly study DM candidates other than WIMPs. A compelling possibility is that DM may strongly interact with itself [4] (self-interacting dark matter or SIDM). We study the SIDM event spectrum in the light of SuperCDMS, LUX, and DAMA, taking into account realistic efficiency and energy resolution of the detectors
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have