2015/02/06 by Oberhof, Benjamin
#FOS: Physical sciences #High Energy Physics - Experiment (hep-ex)
paper · doi:10.48550/arxiv.1502.01810
We perform a measurement of the branching fractions for tau -> l gamma nu anti-nu (l= e, mu) decays for a minimum photon energy of 10 MeV in the tau rest frame using 430 fb-1 of e+ e- collisions collected at the center-of-mass energy of the Upsilon(4S) resonance around 10.58GeV with the BaBar detector at the PEP-II storage rings. We find B(tau -> mu gamma nu nu) = (3.69pm0.03pm0.10)x10-3 and B(tau -> e gamma nu anti-nu) = (1.847pm0.015pm0.052)x10-2 where the first quoted error is statistical and the second is systematic. These results represent a substantial improvement with respect to existing measurements for both channels.