The latest experimental results from CMS collaboration on Heavy Neutral Leptons will be presented. Various HNL production and decay modes are considered to guide the searches. The analysis of the full Run II data leads to stringent constraints on neutrino mass model parameters.
I discuss the interplay of terrestrial and cosmological neutrino mass determinations and highlight the exciting prospects for cosmological observations. Then I discuss a mechanism to modify neutrino evolution in the early Universe, to make "large" neutrino masses consistent with cosmology, and present a simple seesaw scenario to realise such a mechanism in a UV complete model.
Direct searches at fixed target experiments and searches for neutrinoless double beta (0νββ) decay can be used to probe the Majorana vs. pseudo-Dirac nature of a Heavy Neutral Lepton (HNL) pair. Firstly, I will outline a phenomenological parametrisation relating the active-sterile mixing strengths to the neutrino oscillation data, assuming that the HNL pair generates masses for two light...
Nuclear reactions in the solar core can produce light and weakly coupled beyond the standard model particles that subsequently reach the Earth. We analyze the second step of the proton-proton chain, and we investigate the flux of monochromatic 5.49 MeV massive spin-one particles. Focusing on two benchmark scenarios, which correspond to different communication mechanisms with the visible...
Sterile neutrinos are well-motivated extension of the Standard Model. In this talk I will focus on the interaction between sterile neutrinos and light active neutrinos through the magnetic moment portal. I will show that strong constraints can be derived from SN1987A through the non-observation of active neutrinos and photons produced from sterile neutrino decays. Furthermore, sensitivity...
