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arXiv · 0809.2587

Observation of $η'$ decays to $π^+π^-π^0$ and $π^+π^-\e^+e^-$

CLEO Collaboration·P. Naik
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Abstract

Using psi(2S) --> pi+ pi- J/psi, J/psi --> gamma eta' events acquired with the CLEO-c detector at the CESR e+e- collider, we make the first observations of the decays eta' --> pi+ pi- pi0 and eta' --> pi+ pi- e+ e-, measuring absolute branching fractions (37 +11 -9 +- 4) x 10^-4 and (25 +12 -9 +- 5) x 10^-4, respectively. For eta' --> pi+ pi- pi0, this result probes the mechanism of isospin violation and the roles of pi0/eta/eta'-mixing and final state rescattering in strong decays. We also set upper limits on branching fractions for eta' decays to pi+ pi- mu+ mu-, 2(pi+ pi-), pi+ pi- 2pi0, 2(pi+ pi-)pi0, 3(pi+ pi-), and invisible final states.

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CLEO Collaboration, P. Naik. 2009-02-12. Observation of $η'$ decays to $π^+π^-π^0$ and $π^+π^-\e^+e^-$. https://doi.org/10.1103/physrevlett.102.061801

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