TY  - JOUR
AU  - BABAR Collaboration (Lees, J. P. et al
AU  - Martinez-Vidal, F.
AU  - Oyanguren, A.
PY  - 2020
DA  - 2020//
TI  - Precision Measurement of the Ratio B(gamma(3S) -> tau(+)tau(-))/B(gamma(3S) -> mu(+)mu(-))
T2  - Phys. Rev. Lett.
JO  - Physical Review Letters
SP  - 241801
EP  - 7pp
VL  - 125
IS  - 24
PB  - Amer Physical Soc
AB  - 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.
SN  - 0031-9007
UR  - https://arxiv.org/abs/2005.01230
UR  - https://doi.org/10.1103/PhysRevLett.125.241801
DO  - 10.1103/PhysRevLett.125.241801
LA  - English
N1  - WOS:000596461100005
ID  - BABARCollaborationLees_etal2020
ER  -