Speaker
Description
Weak neutrino and antineutrino signals from astrophysical sources can be investigated with high sensitivity with large underground ultrapure liquid scintillators. The largest amount of detected antineutrinos at Earth is emitted in the natural radioactive decays by $^{40}$K and of $^{232}$Th and $^{238}$U chains isotopes, while supernovae explosions, gamma ray bursts, GW events and solar flares are among possible extra-terrestrial sources of antineutrinos. Borexino has clearly detected the geo-neutrino flux, measured the mantle signal and constrained the overall production of radiogenic heat to 38.2 $^{+13.6} _{-12.7}$ TW. The extreme radiopurity of the detector has also allowed to get the best upper limits on all flavor antineutrino fluences in the few MeV energy range from gamma-ray bursts and from gravitational wave events and to set limits on the diffuse supernova antineutrino background in the unexplored energy region below 8 MeV.
Recently, Borexino has published the search for possible events in correlation, within a time window of ±1000 s, with several of the most intense fast radio bursts (FRBs). In parallel, specific energy shapes have been searched for in the full exposure spectrum of the Borexino detector. By combining these methods, the strongest upper limits on FRB-associated neutrino fluences of all flavors have been obtained in the 0.5−50 MeV neutrino energy range.
The talk is aimed to summarise Borexino results on geoneutrinos and on the possible signals from astrophysical sources, with a particular focus on the new search for FRB-associated neutrinos.
| In-person participation | Yes |
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