Two-photon widths of theχcJstates of charmonium

Citations Over TimeTop 10% of 2008 papers

Abstract

Using a data sample of $24.5\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $\ensuremath{\psi}(2S)$ the reactions $\ensuremath{\psi}(2S)\ensuremath{\rightarrow}\ensuremath{\gamma}{\ensuremath{\chi}}_{cJ}$, ${\ensuremath{\chi}}_{cJ}\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\gamma}$ have been studied for the first time to determine the two-photon widths of the ${\ensuremath{\chi}}_{cJ}$ states of charmonium in their decay into two photons. The measured quantities are $\mathcal{B}(\ensuremath{\psi}(2S)\ensuremath{\rightarrow}\ensuremath{\gamma}{\ensuremath{\chi}}_{c0})\ifmmode\times\else\texttimes\fi{}\mathcal{B}({\ensuremath{\chi}}_{c0}\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\gamma})=(2.17\ifmmode\pm\else\textpm\fi{}0.32\ifmmode\pm\else\textpm\fi{}0.10)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}$ and $\mathcal{B}(\ensuremath{\psi}(2S)\ensuremath{\rightarrow}\ensuremath{\gamma}{\ensuremath{\chi}}_{c2})\ifmmode\times\else\texttimes\fi{}\mathcal{B}({\ensuremath{\chi}}_{c2}\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\gamma})=(2.68\ifmmode\pm\else\textpm\fi{}0.28\ifmmode\pm\else\textpm\fi{}0.15)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}$. Using values for $\mathcal{B}(\ensuremath{\psi}(2S)\ensuremath{\rightarrow}\ensuremath{\gamma}{\ensuremath{\chi}}_{c0,c2})$ and $\ensuremath{\Gamma}({\ensuremath{\chi}}_{c0,c2})$ from the literature the two-photon widths are derived to be ${\ensuremath{\Gamma}}_{\ensuremath{\gamma}\ensuremath{\gamma}}({\ensuremath{\chi}}_{c0})=(2.36\ifmmode\pm\else\textpm\fi{}0.35\ifmmode\pm\else\textpm\fi{}0.22)\text{ }\text{ }\mathrm{keV}$, ${\ensuremath{\Gamma}}_{\ensuremath{\gamma}\ensuremath{\gamma}}({\ensuremath{\chi}}_{c2})=(0.66\ifmmode\pm\else\textpm\fi{}0.07\ifmmode\pm\else\textpm\fi{}0.06)\text{ }\text{ }\mathrm{keV}$, and $\mathcal{R}\ensuremath{\equiv}{\ensuremath{\Gamma}}_{\ensuremath{\gamma}\ensuremath{\gamma}}({\ensuremath{\chi}}_{c2})/{\ensuremath{\Gamma}}_{\ensuremath{\gamma}\ensuremath{\gamma}}({\ensuremath{\chi}}_{c0})=0.278\ifmmode\pm\else\textpm\fi{}0.050\ifmmode\pm\else\textpm\fi{}0.036$. The importance of the measurement of $\mathcal{R}$ is emphasized. For the forbidden transition, ${\ensuremath{\chi}}_{c1}\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\gamma}$, an upper limit of ${\ensuremath{\Gamma}}_{\ensuremath{\gamma}\ensuremath{\gamma}}({\ensuremath{\chi}}_{c1})<0.03\text{ }\text{ }\mathrm{keV}$ is established.

Related Papers

• → Prim�rzerlegung in Steinschen Algebren(1964)32 cited
• → �ber unirationale Scharen auf algebraischen Mannigfaltigkeiten(1966)4 cited
• → Produkttreue Klassen universeller Algebren(1969)1 cited
• → Approximation of fixed points of multifunctions in partial metric spaces(2015)
• → ИСПОЛЬЗОВAНИЕ ПОТЕНЦИAЛA СОЦИAЛЬНЫХ ПAРТНЕРОВ В ПОДГОТОВКЕ БУДУЩИХ ПЕДAГОГОВ(2024)