Search for the radiative transition $\ddot{I}{‡}_{c1}(3872)\to {\hat{I}}^3\ddot{I}{ˆ}_2(3823)$

Abstract

Using 9.0 $\mathrm{f}{\mathrm{b}}^{-1}$ of $e^{+}{e}^{-}$ collision data collected at center-of-mass energies from 4.178 to 4.278 GeV with the BESIII detector at the BEPCII collider, we perform the first search for the radiative transition $\ddot{I}{‡}_{c1}(3872)\to {\hat{I}}^3\ddot{I}{ˆ}_2(3823)$. No $\ddot{I}{‡}_{c1}(3872)\to {\hat{I}}^3\ddot{I}{ˆ}_2(3823)$ signal is observed. The upper limit on the ratio of branching fractions $\mathcal{B}(\ddot{I}{‡}_{c1}(3872)\to {\hat{I}}^3\ddot{I}{ˆ}_2(3823),\ddot{I}{ˆ}_2(3823)\to {\hat{I}}^3\ddot{I}{‡}_{c1})/\mathcal{B}(\ddot{I}{‡}_{c1}(3872)\to \ddot{I}{€}^{+}\ddot{I}{€}^{-}J/\ddot{I}ˆ)$ is set as 0.075 at the 90\% confidence level. Our result contradicts theoretical predictions under the assumption that the $\ddot{I}{‡}_{c1}(3872)$ is the pure charmonium state $\ddot{I}{‡}_{c1}(2P)$.

8 pages, 2 figures