Observation of the Transition $ϒ^{'} \to ϒ π^{+} π^{-} \to e^{+} e^{-} π^{+} π^{-}$

Publisher Website

27 April 1981

journal article
research article
Published by American Physical Society (APS) in Physical Review Letters

Vol. 46 (17) , 1115-1118
https://doi.org/10.1103/physrevlett.46.1115

Abstract

In a sample of 10 000

ϒ^{'}

decays observed with our nonmagnetic detector at the Cornell Electron Storage Ring, we find 23 events consistent with the decay

ϒ^{'} \to ϒ π^{+} π^{-} \to e^{+} e^{-} π^{+} π^{-}

. We derive a branching fraction of 0.20±0.07 for

ϒ^{'} \to ϒ π^{+} π^{-}

and estimates of the partial width for this decay. The invariant-mass spectrum of the pion pairs shows a strong preference for large di-pion mass.

Keywords

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