%0 Journal Article
%T Precision Measurement of the Ratio B(gamma(3S) -> tau(+)tau(-))/B(gamma(3S) -> mu(+)mu(-))
%A BABAR Collaboration (Lees, J. P. et al
%A Martinez-Vidal, F.
%A Oyanguren, A.
%J Physical Review Letters
%D 2020
%V 125
%N 24
%I Amer Physical Soc
%@ 0031-9007
%G English
%F BABARCollaborationLees_etal2020
%O WOS:000596461100005
%O exported from refbase (https://references.ific.uv.es/refbase/show.php?record=4672), last updated on Tue, 19 Jan 2021 08:38:13 +0000
%X We report on a precision measurement of the ratio R-tau mu(gamma(3s)) = B(gamma(3S) -> tau(+)tau(-))/B(tau(gamma(3S) ->mu(+)mu(-)) using data collected with the BABAR detector at the SLAC PEP-II e(+)e(-) collider. The measurement is based on a 28 fb(-1) data sample collected at a center-of-mass energy of 10.355 GeV corresponding to a sample of 122 million gamma(35) mesons. The ratio is measured to be R-tau mu(gamma(3s)) = 0.966 +/- 0.008(stat) +/- 0.014(syst) and is in agreement with the standard model prediction of 0.9948 within 2 standard deviations. The uncertainty in R-tau mu(gamma(3s)) is almost an order of magnitude smaller than the only previous measurement.
%R 10.1103/PhysRevLett.125.241801
%U https://arxiv.org/abs/2005.01230
%U https://doi.org/10.1103/PhysRevLett.125.241801
%P 241801-7pp