Neutrinos are neutral elementary particles that account for up to half of the composition of cosmic rays.
In 2015, ANITA project, joint missionscientists from NASA and the Russian National Research Nuclear University MEPhI, discovered three particles, tau neutrinos of ultrahigh energies, which significantly violated the limits of Graisen – Zatsepin – Kuzmin. This limit assumes the existence of neutrinos with energies of up to eight joules - if this limit is exceeded, according to the Standard Model, neutrinos interact with the microwave background radiation of the Universe, form new particles and lose energy.
ANITA researchers discoverneutrinos whose energy exceeded eight joules — that is, exceeded the Greisen – Zatsepin – Kuzmin threshold. However, these particles were not affected by the laws described by the Standard Model, and they were able to save energy.
Now researchers from the IceCube observatory have been able to prove that tau neutrinos recorded by ANITA are not of cosmic origin.
“Our analysis ruled out the latter possibilityan astrophysical explanation for the origin of these particles that the Standard Model allows for. Accordingly, if these events were actually recorded by ANITA instruments, and were not generated by observational errors, they indicate the existence of “new physics.”
Alex Pizzuto, lead author of the study
IceCube previously detected a neutrino outbreakalong with gravitational waves. IceCube's neutrino laboratory has detected a neutrino burst that originates from the same point where the LIGO and VIRGO gravitational telescopes detected a burst of gravitational waves. A bunch of these neutrinos could spawn a fusion of a black hole and a neutron star.