Search for the decay J/psi -> gamma plus invisible

Abstract

We search for J/psi radiative decays into a weakly interacting neutral particle, namely an invisible particle, using the J/psi produced through the process psi(3686) -> pi(+)pi(-) J/psi in a data sample of (448.1 +/- 2.9) x 10(6) psi(3686) decays collected by the BESIII detector at BEPCII. No significant signal is observed. Using a modified frequentist method, upper limits on the branching fractions are set under different assumptions of invisible particle masses up to 12 GeV/c(2). The upper limit corresponding to an invisible particle with zero mass is 7.0 x 10(-7) at the 90% confidence level.