Search for resonances decaying to ηcπ+π− in two-photon interactions

Le résumé fourni par la source

We report a study of the process $\ensuremath{\gamma}\ensuremath{\gamma}\ensuremath{\rightarrow}X\ensuremath{\rightarrow}{\ensuremath{\eta}}_{c}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$, where $X$ stands for one of the resonances ${\ensuremath{\chi}}_{c2}(1P)$, ${\ensuremath{\eta}}_{c}(2S)$, $X(3872)$, $X(3915)$, or ${\ensuremath{\chi}}_{c2}(2P)$. The analysis is performed with a data sample of $473.9\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ collected with the BABAR detector at the PEP-II asymmetric-energy electron-positron collider. We do not observe a significant signal for any channel, and calculate 90% confidence-level upper limits on the products of branching fractions and two-photon widths ${\ensuremath{\Gamma}}_{X\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\gamma}}\mathcal{B}(X\ensuremath{\rightarrow}{\ensuremath{\eta}}_{c}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}})$: 15.7 eV for ${\ensuremath{\chi}}_{c2}(1P)$, 133 eV for ${\ensuremath{\eta}}_{c}(2S)$, 11.1 eV for $X(3872)$ (assuming it to be a spin-2 state), 16 eV for $X(3915)$ (assuming it to be a spin-2 state), and 18 eV for ${\ensuremath{\chi}}_{c2}(2P)$. We also report upper limits on the ratios of branching fractions $\mathcal{B}({\ensuremath{\eta}}_{c}(2S)\ensuremath{\rightarrow}{\ensuremath{\eta}}_{c}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}})/\mathcal{B}({\ensuremath{\eta}}_{c}(2S)\ensuremath{\rightarrow}{K}_{S}^{0}{K}^{+}{\ensuremath{\pi}}^{\ensuremath{-}})<10.0$ and $\mathcal{B}({\ensuremath{\chi}}_{c2}(1P)\ensuremath{\rightarrow}{\ensuremath{\eta}}_{c}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}})/\mathcal{B}({\ensuremath{\chi}}_{c2}(1P)\ensuremath{\rightarrow}{K}_{S}^{0}{K}^{+}{\ensuremath{\pi}}^{\ensuremath{-}})<32.9$ at the 90% confidence level.

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