Speaker
Fabio Anulli
(ROMA1)
Description
We search for single-photon events in 53 fb-1 of e+e- collision data collected with the BABAR detector at the PEP-II B-factory. We look for events with a single high-energy photon and a large missing momentum and energy, consistent with production of a spin-1 particle A’ through the process e+e- -> gamma A’, A’ -> invisible. Such particles, referred to as “dark photons”, are motivated by theories applying a U(1) gauge symmetry to dark matter. We find no evidence for such processes and set 90% confidence level upper limits on the coupling strength of A’ to e+e- for a dark photon with a mass lower than 8 GeV. In particular, our limits exclude the values of the A’ coupling suggested by the dark-photon interpretation of the muon (g-2) anomaly, as well as a broad range of parameters.
Primary author
Fabio Anulli
(ROMA1)
