Searching for dark photons in hyperon decays

TL;DR

This paper investigates the potential for detecting massless dark photons through hyperon decays with missing energy, considering constraints from kaon processes and highlighting experimental prospects.

Contribution

It introduces a simplified model for hyperon decays involving dark photons and assesses their branching ratios within existing experimental constraints.

Findings

Branching fractions of hyperon decays could reach a few times 10^{-4}.

Current and future experiments may detect these dark photon signatures.

Constraints from kaon sector limit the parameter space for hyperon decay rates.

Abstract

That massless dark photons could exist and have flavor-changing magnetic-dipole interactions with down-type light quarks is an attractive possibility which may be realized in various new-physics scenarios. It is potentially testable not only in kaon processes but also via two-body hyperon decays involving missing energy carried away by the massless dark photon. We explore the latter within a simplified model approach and take into account constraints from the kaon sector. We find that the branching fractions of some of these hyperon modes are allowed to be as high as a few times $10^{-4}$. Such numbers are likely to be within the sensitivity reaches of ongoing experiments like BESIII and future ones at super charm-tau factories.