Abstract
The Mark III Collaboration has measured the J/ψ leptonic branching fractions using the process ψ(2S)→J/ψ, J/ψ→. The results are B(J/ψ→)=(5.92±0.15±0.20)% and B(J/ψ→)=(5.90±0.15±0.19)%, where the first error is statistical and the second is systematic. Assuming lepton universality, the leptonic branching fraction of the J/ψ is (5.91±0.11±0.20)%. This result is used to obtain the strong coupling constant and the QCD scale factor (MS¯ denotes the modified minimal-subtraction scheme).
- Received 12 August 1991
DOI:https://doi.org/10.1103/PhysRevLett.68.282
©1992 American Physical Society