Search for ψ(2S)→ηcπ+π-π0

Le résumé fourni par la source

Using $5.63\text{ }\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$ of data accumulated at the $\ensuremath{\psi}(2S)$ resonance with the CLEO III and CLEO-c detectors corresponding to $3.08\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $\ensuremath{\psi}(2S)$ decays, a search is performed for the decay $\ensuremath{\psi}(2S)\ensuremath{\rightarrow}{\ensuremath{\eta}}_{c}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{0}$ to test a theoretical prediction based upon the assumption that the $c\overline{c}$ pair in the $\ensuremath{\psi}(2S)$ does not annihilate directly into three gluons but rather survives before annihilating. No signal is observed, and a combined upper limit from six ${\ensuremath{\eta}}_{c}$ decay modes is determined to be $\mathcal{B}(\ensuremath{\psi}(2S)\ensuremath{\rightarrow}{\ensuremath{\eta}}_{c}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{0})\ensuremath{\le}1.0\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$ at 90% C.L. This upper limit is about an order of magnitude below the theoretical expectation.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.