## Strong constraint on dark matter - neutrino interactions via light vector bosons    [PDF]

Ranjan Laha, Basudeb Dasgupta, John F Beacom
Dark matter velocity-dependent self-interactions and interactions with neutrinos mediated by a new MeV-scale vector boson V have been shown to solve all the small-scale-structure problems in a $\Lambda$CDM cosmology [van den Aarssen et al.; PRL (2012)]. We show that such interactions with Standard Model neutrinos lead to "V-strahlung" from neutrinos in the final states of kaon and W decays, producing vastly too many missing-energy events. The proposed model is thus strongly excluded. More generally, we present new constraints on the coupling strength to neutrinos, $g_\nu \lesssim 8\times 10^{-5} (m_V/MeV)$, for a light vector boson of mass m_V. These model-independent constraints provide one of the most stringent bounds on additional neutrino interactions.
View original: http://arxiv.org/abs/1304.3460