Search for a massless dark photon in $\Lambda^{+}_{c}\to p \gamma^{\prime}$ decay

TL;DR

This paper reports a search for a massless dark photon in $\Lambda^{+}_{c} o p \gamma^{}$ decay using BESIII data, setting an upper limit on the decay's branching fraction due to no observed signal.

Contribution

First search for a massless dark photon in $\Lambda^{+}_{c}$ decay, establishing an upper limit on its branching fraction with experimental data.

Findings

No significant dark photon signal observed.

Upper limit on branching fraction set at $8.0\times 10^{-5}$.

Data collected at center-of-mass energies 4.600-4.699 GeV.

Abstract

A search for a massless dark photon $\gamma^{\prime}$ is conducted using 4.5 $\mathrm{fb}^{-1}$ of $e^+e^-$ collision data collected at center-of-mass energies between 4.600 and 4.699 $\mathrm{GeV}$ with the BESIII detector at BEPCII. No significant signal is observed, and the upper limit on the branching fraction $\mathcal{B}(\Lambda^{+}_{c}\to p \gamma^{\prime})$ is determined to be $8.0\times 10^{-5}$ at 90% confidence level.