We report on a precision measurement of the ratio Rτμϒ(3S)=B(ϒ(3S)→τ+τ-)/B(ϒ(3S)→μ+μ-) 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 ϒ(3S) mesons. The ratio is measured to be Rτμϒ(3S)=0.966±0.008stat±0.014syst and is in agreement with the standard model prediction of 0.9948 within 2 standard deviations. The uncertainty in Rτμϒ(3S) is almost an order of magnitude smaller than the only previous measurement.

Precision Measurement of the Ratio B (ϒ (3S) →τ+τ-) / B (ϒ (3S) →μ+μ-)

Li Y.;Finocchiaro G.;Banerjee S.;Cenci R.;Marchiori G.;Batignani G.;Lusiani A.
Membro del Collaboration Group
;
Ferroni F.;
2020

Abstract

We report on a precision measurement of the ratio Rτμϒ(3S)=B(ϒ(3S)→τ+τ-)/B(ϒ(3S)→μ+μ-) 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 ϒ(3S) mesons. The ratio is measured to be Rτμϒ(3S)=0.966±0.008stat±0.014syst and is in agreement with the standard model prediction of 0.9948 within 2 standard deviations. The uncertainty in Rτμϒ(3S) is almost an order of magnitude smaller than the only previous measurement.
2020
Settore FIS/01 - Fisica Sperimentale
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11384/126449
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