Impact of sterile neutrinos on the early time flux from a galactic supernova

Understand

We study the impact of the existence of an eV-mass scale sterile neutrino---with parameters in the ballpark of what is required to fit the laboratory anomalies---on the early time profile of the electron neutrino and antineutrino fluxes associated to a core-collapse supernova (SN).

• In particular, we focus on the universal feature of neutronization burst expected in the first tens of ms of the signal: provided that a detector with sufficient sensitivity is available, it is well-known that in the 3 neutrino framework the detection of the neutronization burst in neutrino channel would signal inverted mass hierarchy.
• This conclusion is dramatically altered in the presence of a sterile neutrino: we study here both analytically and numerically the region in parameter space where this characteristic signal disappears, mimicking normal hierarchy expectations.
• Conversely, the detection of a peak consistent with expectations for inverted mass hierarchy would exclude the existence of a sterile state over a much wider parameter space than what required by laboratory anomalies fits, or even probed by detectors coming on-line in the near future.