Impact of the active-sterile MSW resonance on fast flavor neutrino conversions in supernovae

Madhurima Chakraborty^1*, Sovan Chakraborty²

¹Institute of Physics, Academia Sinica, Taipei, Taiwan
²Department of Physics, Indian Institute of Technology, Guwahati, Guwahati, Assam, India

* Presenter:Madhurima Chakraborty, email:madhurimac412@gmail.com

Sterile neutrinos are the hypothetical singlet fermions which interact with ordinary matter only through mixing with the active neutrinos. In the context of Supernovae (SN), the generation of $\nu_s, \bar \nu_s$ through Mikheyev-Smirnov-Wolfenstein (MSW) conversions of $\nu_e, \bar \nu_e$ for the eV mass sterile species have been found to affect the SN explosion and nucleosynthesis in an appreciable manner. Motivated from this, it becomes interesting to probe the effect of these kinds of MSW conversions on the fast flavor conversions (FFC's) of neutrinos occurring deep inside the SN core. In this work, we investigate the possible impact of the $\nu_e, \bar \nu_e$ - $\nu_s, \bar \nu_s$ oscillations on the zero crossings in the neutrino flavor lepton number in a 2+1 scenario (2 active and 1 sterile species) as the presence of the latter is a crucial factor in the development of FFC's. We show, through a representative example of an outer resonance, that the corresponding change in the number of $\nu_e, \bar \nu_e$ due to MSW resonance can potentially modify the subsequent ELN crossings and thus affect the occurrence of FFC's significantly. Further, we carry out a qualitative analysis taking into account the scenario of inner resonance as well.

Keywords: Neutrinos, Neutrino oscillations, Supernovae, Fast flavor Conversions, Sterile