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Measurement of the branching fractions for psi(2S)-->e+e- and psi(2S)-->mu+mu-

B. Aubert·the BABAR Collaboration
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Abstract

We measure the branching fractions of the psi(2S) meson to the leptonic final states e+e- and mu+mu- relative to that for psi(2S)-->J/psi pi+pi-. The method uses psi(2S) mesons produced in the decay of B mesons at the Upsilon(4S) resonance in a data sample collected with the BABAR detector at the Stanford Linear Accelerator Center. Using previous measurements for the psi(2S)-->J/psi pi+pi- branching fraction, we determine the e+e- and mu+mu- branching fractions to be 0.0078+/-0.0009+/-0.0008 and 0.0067+/-0.0008+/-0.0007 respectively.

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B. Aubert, the BABAR Collaboration. 2003-01-09. Measurement of the branching fractions for psi(2S)-->e+e- and psi(2S)-->mu+mu-. https://doi.org/10.1103/physrevd.65.031101

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