We have studied the leptonic decay of the γ (1S) resonance into tau pairs using the CLEO II detector. A clean sample of tau pair events is identified via events containing two charged particles where exactly one of the particles is an identified electron. We find B(γ(1S) → τ+τ-) = (2.61±0.12-0.13 +0.09)%. The result is consistent with expectations from lepton universality.
Bibliographical noteFunding Information:
We gratefully acknowledge the effort of the CESR staff in providing us with excellent luminosity and running conditions. LEA. and P.S.D. thank the PYI program of the NSF, I.P.J.S. thanks the YI program of the NSF, G.E. thanks the Heisenberg Foundation, I.P.J.S., and T.S. thank the TNRLC, K.K.G., M.S., H.N.N., J.D.R., T.S. and H.Y. thank the OJI program of DOE and P.R. thanks the A.P. Sloan Foundation for support. This work was supported by the National Science Foundation, the U.S. Dept. of Energy and the Natural Sciences and Engineering Research Council of Canada.
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics