Study of $e^{+}{e}^{-}\to \ddot{I}‰X(3872)$ and ${\hat{I}}^{3}X(3872)$ from 4.66 to 4.95 GeV

Abstract

Using data samples with an integrated luminosity of $4.5{\text{fb}}^{-1}$ collected by the BESIII detector at center-of-mass energies ranging from 4.66 to 4.95 GeV, we study the processes of $e^{+}{e}^{-}\to \ddot{I}‰X(3872)$ and $e^{+}{e}^{-}\to {\hat{I}}^{3}X(3872)$. With the $e^{+}{e}^{-}\to \ddot{I}‰X(3872)$ process, the branching fraction ratio $R\equiv \frac{\mathcal{B}(X(3872)\to {\hat{I}}^{3}J/\ddot{I}ˆ)}{\mathcal{B}(X(3872)\to \ddot{I}{€}^{+}\ddot{I}{€}^{-}J/\ddot{I}ˆ)}$ is measured to be $0.38\pm 0.20_{\text{stat.}}\pm 0.01_{\text{syst.}}$ ($R<0.83$ at 90\% confidence level). In addition, we measure the ratio of the average cross section of $e^{+}{e}^{-}\to \ddot{I}‰X(3872)$ to $e^{+}{e}^{-}\to \ddot{I}‰\ddot{I}{‡}_{c1}(\ddot{I}‰\ddot{I}{‡}_{c2})$ to be $\ddot{I}{ƒ}_{\ddot{I}‰X(3872)}/\ddot{I}{ƒ}_{\ddot{I}‰\ddot{I}{‡}_{c1}}(\ddot{I}{ƒ}_{\ddot{I}‰X(3872)}/\ddot{I}{ƒ}_{\ddot{I}‰\ddot{I}{‡}_{c2}})=5.2\pm 1.0_{\text{stat.}}\pm 1.9_{\text{syst.}}(5.5\pm 1.1_{\text{stat.}}\pm 2.4_{\text{syst.}})$. Finally, we search for the process of $e^{+}{e}^{-}\to {\hat{I}}^{3}X(3872)$, and no obvious signal is observed. The upper limit on the ratio of the average cross section of $e^{+}{e}^{-}\to {\hat{I}}^{3}X(3872)$ to $e^{+}{e}^{-}\to \ddot{I}‰X(3872)$ is set as $\ddot{I}{ƒ}_{{\hat{I}}^{3}X(3872)}/\ddot{I}{ƒ}_{\ddot{I}‰X(3872)}<0.23$ at 90\% confidence level.

19 pages, 10 figures