Lees, J. P.Poireau, V.Tisserand, V.Grauges, E.Palano, A.Eigen, G.Stugu, B.Izen, Joseph M.Lou, XinchouBaBar Collaboration2015-01-122015-01-122014-11-102014-11-100031-9007http://hdl.handle.net/10735.1/4256Includes supplementary materialDark sectors charged under a new Abelian interaction have recently received much attention in the context of dark matter models. These models introduce a light new mediator, the so-called dark photon (A′), connecting the dark sector to the standard model. We present a search for a dark photon in the reaction e⁺e⁻ → γA′, A′ → e⁺e⁻, μ⁺μ⁻ using 514 fb⁻¹ of data collected with the BABAR detector. We observe no statistically significant deviations from the standard model predictions, and we set 90% confidence level upper limits on the mixing strength between the photon and dark photon at the level of 10⁻⁴ − 10⁻³ for dark photon masses in the range 0.02-10.2 GeV. We further constrain the range of the parameter space favored by interpretations of the discrepancy between the calculated and measured anomalous magnetic moment of the muon.en-US©2014 American Physical SocietyDark photonsMuonsElectronsAbelian interactionsTextLees, J. P., V. Poireau, V. Tisserand, E. Grauges, et al. 2014. "Search for a dark photon in e⁺e⁻ collisions at BABAR." Physical Review Letters 113(20), doi:10.1103/PhysRevLett.113.20180111320