Solutions to the MiniBooNE Anomaly from New Physics in Charged Meson Decays

TL;DR

This paper proposes that charged meson decays producing new bosons can significantly improve the detection of new physics signals in accelerator experiments, offering a potential explanation for the MiniBooNE anomaly through dark-sector models.

Contribution

It introduces a novel mechanism involving charged meson decays to explain the MiniBooNE excess, connecting dark-sector models with experimental testability.

Findings

Charged meson decays can enhance sensitivity to new physics signals.

Dark-sector models can explain the MiniBooNE excess without conflicting with existing limits.

The proposed models are testable at current and future neutrino experiments.

Abstract

We point out that production of new bosons by charged meson decays can greatly enhance the sensitivity of beam-focused accelerator-based experiments to new physics signals. This enhancement arises since the charged mesons are focused and their three-body decays do not suffer from helicity suppression in the same way as their usual two-body decays. As a realistic application, we attempt to explain the MiniBooNE low energy excess utilizing this overlooked mechanism, uniquely realizing dark-sector interpretations as plausible solutions to the excess. As proof of the principle, we consider two well-motivated classes of dark-sector models, models of vector-portal dark matter and models of long-lived (pseudo)scalar. We argue that the model parameter values to accommodate the excess are consistent with existing limits and that they can be tested at current and future accelerator-based neutrino experiments.