Spin rotation of neutrinos produced by compact magnetized astrophysical objects

TL;DR

This paper investigates how strong magnetic fields near compact objects like magnetars influence neutrino spin and flavor transitions, affecting their detectability and flux anisotropy.

Contribution

It provides a detailed analysis of neutrino spin-flavor evolution in realistic magnetic fields, including transition probabilities and flux anisotropies from magnetars.

Findings

Neutrino helicity can significantly change during propagation near magnetars.

Fluxes of left- and right-handed neutrinos are anisotropic due to magnetic field effects.

A fraction of neutrinos become unobservable after spin-flip transitions.

Abstract

We study the propagation of neutrinos from compact astrophysical objects with strong magnetic field, such as magnetars. Both neutrino spin rotation and oscillations in a realistic three-flavor model are taken into account. We solve the neutrino evolution equation in the magnetic field near the object and obtain the probabilities of all possible spin-flavor transitions. Assuming that neutrinos are produced in the interior of the star being in their left-handed state with electron flavor, we use these spin-flavor transition probabilities to estimate the fraction of neutrinos, which change their helicity during propagation to the Earth and thus become unobservable. Using the model of the magnetar with dipolar magnetic field, we demonstrate anisotropy in the left-handed and right-handed neutrino fluxes from such astrophysical objects.