Gamma-ray bursts and the relevance of rotation-induced neutrino sterilization

TL;DR

This paper explores how rotation-induced helicity flips in neutrinos emitted by rotating astrophysical objects can significantly impact neutrino detection and interpretation, especially relevant for high-energy neutrino observations like those from IceCube.

Contribution

It generalizes the Pontecorvo formalism to include rotation effects on neutrino helicity states, highlighting their importance in astrophysical neutrino detection.

Findings

Rotation can cause significant helicity flips in neutrinos from rotating sources.

Helicity-flipped states have suppressed electroweak cross sections, affecting detection.

Implications for interpreting IceCube neutrino data are discussed.

Abstract

A la Pontecorvo when one defines electroweak flavour states of neutrinos as a linear superposition of mass eigenstates one ignores the associated spin. If, however, there is a significant rotation between the neutrino source, and the detector, a negative helicity state emitted by the former acquires a non-zero probability amplitude to be perceived as a positive helicity state by the latter. Both of these states are still in the left-Weyl sector of the Lorentz group. The electroweak interaction cross sections for such helicity-flipped states are suppressed by a factor of $(m_\nu/E_\nu)^2$, where $m_\nu$ is the expectation value of the neutrino mass, and $E_\nu$ is the associated energy. Thus, if the detecting process is based on electroweak interactions, and the neutrino source is a highly rotating object, the rotation-induced helicity flip becomes very significant in interpreting the data. The effect immediately generalizes to anti-neutrinos. Motivated by these observations we present a generalization of the Pontecorvo formalism and discuss its relevance in the context of recent data obtained by the IceCube neutrino telescope.