Spin oscillations of neutrinos scattered off a rotating black hole

Abstract

Spin oscillations of neutrinos, gravitationally scattered off a black hole (BH), are studied. The cases of nonrotating and rotating BHs are analyzed. We derive the analytic expressions for the transition and survival probabilities of spin oscillations when neutrinos interact with these gravitational backgrounds. The obtained transition probabilities depend on the impact parameter, as well as the neutrino energy and the particle mass. We find that there is a possibility of spin oscillations of ultrarelativistic neutrinos scattering off a rotating BH. Then, considering the neutrino scattering off BH surrounded by background matter, we derive the effective Schrödinger equation for spin oscillations. The numerical solution of this equation is obtained in the case of a supermassive BH with a realistic accretion disk. Spin effects turn out to be negligible in the neutrino scattering in the Schwarzschild metric. In the Kerr metric, we find that the observed neutrino fluxes can be reduced almost 10% because of spin oscillations when ultrarelativistic neutrinos experience gravitational scattering. The neutrino interaction with an accretion disk results in the additional modification of the intensities of outgoing neutrino fluxes. We consider the applications of the obtained results for the neutrino astronomy.

Gravitational scattering of spinning neutrinos by a rotating black hole with a slim magnetized accretion disk

“…The gravitational scattering of fermions, including neutrinos, was studied in [17][18][19]. We analyzed this problem in [20][21][22] accounting for only the equatorial neutrino motion. Now, for the first time, we discuss this problem in a quite general form.…”

Shadow, lensing and neutrino propagation by dyonic ModMax black holes

“…This is a consequence of the fact that one has to consider relativistic neutrinos. Moreover, we have only considered the effects of the gravitational field, while a complete analysis should include the magnetic field [210]. We have also discussed the influence of the dyonic ModMax geometry on the nucleosynthesis processes, getting a difference ∼ 5%, with respect to GR, could be relevant in the supernovae evolution.…”

Neutrino spin oscillations in conformally gravity coupling models and quintessence surrounding a black hole

“…Some final comments are in order: 1) We have only considered the spin-flip transitions induced by gravitational fields. A more complete analysis requires the inclusion of magnetic field, as in [76]; 2) The spin flip probability (18), when applied to solar neutrinos, gives a probability below the upper bound 0.07, obtained from the Kamiokande-II [91]. 3) We have assumed that the conformal factor A(φ) is universal so that the equivalence principle holds [92].…”

“…1, we have used a factor A = 1, recovering the results in Ref. [76] (with a factor 1/2 overall). In the case of the chameleon theory, the conformal factor A(φ) is given by (24).…”

“…In this Section we treat the neutrino spin oscillation problem in a generic gravitational metric. We follow the papers by Dvornikov [76] and Obukhov-Silenko-Teryaev [77]. The motion of a spinning particle in gravitational fields is related to its spin tensor S µν and momentum p µ…”