Sterile neutrinos and supernova nucleosynthesis

Abstract

A light sterile neutrino species has been introduced to explain simultaneously the solar and atmospheric neutrino puzzles and the results of the LSND experiment, while providing for a hot component of dark matter. Employing this scheme of neutrino masses and mixings, we show how matter-enhanced active-sterile (ν µ,τ ν s ) neutrino transformation followed by active-active (ν µ,τ ν e ) neutrino transformation can solve robustly the neutron deficit problem encountered by models of r-process nucleosynthesis associated with neutrino-heated supernova ejecta.

Active–sterile neutrino conversion: consequences for the r-process and supernova neutrino detection

“…are not unrealistic at very late times, where the r-process elements are likely still being made [28].…”

“…In this case, neutrinos which were originally electron flavor when they left the neutrino sphere are almost completely coincident with the ν 3 state. This state evolves separately and does not encounter subsequent mixing with the other flavors [27,28]. In this special case of complete transformation at the δm 2 13 resonance, it would be more difficult to recognize the effects of a ν e ↔ ν s transformation at a higher density.…”

Neutrino Mixing Schemes

“…Values of δm 2 above 10 eV 2 are also allowed for sin 2 2θ ≃ 0.0025 [22]. The future MiniBooNE experiment [23] is expected to either confirm or refute the LSND result.…”

“…Ref. [22] The vacuum neutrino flavor oscillation probabilities, for an initially produced ν α to a finally detected ν β , can be written [26] …”

Supernova neutrino–nucleus astrophysics

“…Reducing the ν e flux will resolve this problem, but we can only do so at a relatively large radius so that effective neutrino heating already can have occurred. One way to achieve this is transforming active electron neutrinos into sterile neutrinos [40,42,43,45].…”