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30 May 2022 to 4 June 2022
Virtual Seoul
Asia/Seoul timezone

Dark sectors in neutrons-shining-through-a-wall and nuclear absorption in neutrino facilities

Not scheduled
Virtual Seoul

Virtual Seoul

Poster Other Poster


Nirmal Raj (TRIUMF National Lab)


I propose new searches for a hidden/dark neutron that can mix with the Standard Model neutron. IsoDAR, a proposal to place an intense cyclotron near a large-volume neutrino detector deep underground, can look for a neutron regeneration signal with much lower backgrounds than surface experiments. This neutron-shining-through-a-wall search would be possible without any modifications to the experiment and would provide the strongest laboratory constraints on the neutron-dark neutron mixing for a wide range of mass splittings. Considering also dark neutrons as dark matter, I show that their nuclear absorption at deep-underground detectors such as SNO and Borexino places some of the strongest limits. Finally,
I describe other signatures, such as neutrons shining through walls at spallation sources, reactors, and the disappearance of ultracold neutrons.

Primary author

Nirmal Raj (TRIUMF National Lab)


Prof. Maxim Pospelov (U Minnesota) Matheus Hostert (Perimeter Institute) David McKeen (TRIUMF )

Presentation Materials