Seminario di Dipartimento: Why and how the Sun and the stars shine (videoregistrazione disponibile)
Physics Department seminar
DIPARTIMENTO DI FISICA, VIA CELORIA 16, MILANO
Aula Consiglio VIRTUALE, link dedicato
19 Maggio 2021– 14:30
Università di Milano and INFN Milano
Why and how the Sun and the stars shine
The millennial question of mankind, what the lights present the sky were and how they were able to shine, has now a definitive answer thanks to a unique experiment, Borexino, located in the Gran Sasso laboratories. The hypothesis (1930) of H. Bethe and C.F. Von Weizsäcker, that the the Sun is dominated by a cycle (pp) of nuclear fusion reactions, involving light nuclei, was experimentally confirmed by Borexino which identified the reactions that emit neutrinos. This cycle, however, 99% dominant in the Sun, according to astrophysical theories is strongly minority in massive stars, dominated instead by a cycle involving carbon, oxygen, nitrogen (CNO). The existence of this second cycle, never confirmed experimentally, has been reached for the first time again by Borexino, exploiting its contribution of 1% in the Sun.
Borexino's results also made an important contribution to the study of neutrino oscillation, measuring the survival probability of the electron-neutrino from the vacuum regime to oscillation in matter, covering an energy range from 150 keV to 17 MeV.
Students are cordially invited