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arXiv · hep-ph/9801226

An Explanation for the rho-pi Puzzle of J/psi and psi' Decays

Yu-Qi Chen·Eric Braaten
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Abstract

We propose a new explanation for the longstanding puzzle of the tiny branching fraction of psi' -> rho pi relative to that for J/psi -> rho pi. In the case of J/psi, we argue that this decay is dominated by a higher Fock state in which the ccbar pair is in a color-octet ^3S_1 state and via annihilate process ccbar -> qqbar. In the case of the psi', we argue that the probability for the ccbar pair in this higher Fock state to be close enough to annihilate is suppressed by a dynamical effect related to the small energy gap between the mass of the psi' and the DDbar threshold.

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Yu-Qi Chen, Eric Braaten. 1998-02-05. An Explanation for the rho-pi Puzzle of J/psi and psi' Decays. https://doi.org/10.1103/physrevlett.80.5060

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