Measurement of the branching ratios ${\psi }^{\prime }\to e^{+}{e}^{-}$, ${\psi }^{\prime }\to J/\psi \pi \pi$ and ${\psi }^{\prime }\to J/\psi \eta$

M. Andreotti, S. Bagnasco, W. Baldini +46

We have measured several branching ratios for ${\psi }^{\prime }$ decay using the data collected by FNAL E835 experiment during year 2000, obtaining ${\cal B}(ψ^\prime \to e^+ e^-) = 0.0068…