Lorentz- and CPT-violating neutrinos from string/D-brane model

TL;DR

This paper proposes a string/D-brane space-time foam model where neutrinos exhibit energy-dependent speeds and Lorentz/CPT violations, potentially explaining IceCube neutrino observations while remaining consistent with decay constraints.

Contribution

It introduces a novel string theory-based model predicting Lorentz and CPT violation effects specifically for neutrinos, linking theoretical predictions with astrophysical observations.

Findings

Neutrinos can have linearly energy-dependent speed variations.

The model predicts an asymmetry between neutrinos and antineutrinos.

Compatibility with IceCube ultrahigh-energy neutrino data and decay constraints.

Abstract

We show that the space-time foam model from string/D-brane theory predicts a scenario in which neutrinos can possess linearly energy dependent speed variation, together with an asymmetry between neutrinos and antineutrinos, indicating the possibility of Lorentz and CPT symmetry violation for neutrinos. Such scenario is supported by a phenomenological conjecture from the possible associations of IceCube ultrahigh-energy neutrino events with the gamma-ray bursts. It is also consistent with the constraints set by the energy-losing decay channels~(e.g., $e^{+}e^{-}$ pair emission, or neutrino splitting) upon superluminal neutrino velocities. We argue that the plausible violations of energy-momentum conservation during decay may be responsible for the stable propagation of these neutrinos, and hence for the evasion of relevant constraints.