Gauged L_mu - L_tau and different Muon Neutrino and Anti-Neutrino Oscillations: MINOS and beyond

TL;DR

This paper explores how a light Z' gauge boson from gauged L_mu - L_tau symmetry could cause flavor-dependent potentials affecting muon neutrino oscillations, potentially explaining MINOS anomalies and influencing future experiments.

Contribution

It introduces a long-range leptonic force model with a light Z' boson to explain neutrino oscillation discrepancies without CP or CPT violation, linking it to muon g-2 and neutrino mixing.

Findings

Potential explains MINOS neutrino-antineutrino oscillation differences.

Atmospheric neutrino mixing must be non-maximal under this model.

Neutrino masses are predicted to be quasi-degenerate.

Abstract

If a Z' gauge boson of a gauged L_mu - L_tau symmetry is very light, it is associated with a long-range leptonic force. In this case the particles in the Sun create via mixing of Z' with the Standard Model Z a flavor-dependent potential for muon neutrinos in terrestrial long-baseline experiments. The potential changes sign for anti-neutrinos and hence can lead to apparent differences in neutrino and anti-neutrino oscillations without introducing CP or CPT violation. This could for instance explain the recently found discrepancy in the survival probabilities of muon neutrinos and anti-neutrinos in the MINOS experiment. We obtain the associated parameters of gauged L_mu - L_tau required to explain this anomaly. The consequences for future long-baseline experiments and for the anomalous magnetic moment of the muon are discussed. The main feature of our explanation is that atmospheric neutrino mixing has to be non-maximal. Neutrino masses tend to be quasi-degenerate.