Lepton-pair Cerenkov radiation emitted by tachyonic neutrinos: Lorentz-covariant approach and IceCube data

TL;DR

This paper investigates the possibility of superluminal or tachyonic neutrinos, deriving Lorentz-invariant constraints on their mass from lepton pair Cerenkov radiation and discussing implications for IceCube neutrino observations.

Contribution

It introduces a Lorentz-covariant approach to constrain tachyonic neutrino masses and calculates decay rates, providing new bounds relevant to high-energy neutrino observations.

Findings

Tight constraints on tachyonic neutrino mass from Lorentz-invariant dispersion relations.

Calculated decay and energy loss rates due to LPCR.

Discussed potential IceCube spectral cutoff at energies above 2 PeV.

Abstract

Current experiments do not exclude the possibility that one or more neutrinos are very slightly superluminal or that they have a very small tachyonic mass. Important bounds on the size of a hypothetical tachyonic neutrino mass term are set by lepton pair Cerenkov radiation (LPCR), i.e., by the decay channel nu -> e^+ e^- nu which proceeds via a virtual Z0 boson. Here, we use a Lorentz-invariant dispersion relation which leads to very tight constraints on the tachyonic mass of neutrinos; we also calculate decay and energy loss rates. A possible cutoff seen in the IceCube neutrino spectrum for E_nu > 2 PeV, due to the potential onset of LPCR, is discussed.