Search for the radiative transition ${\chi }_{c1}\left(3872\right)\to \gamma {\psi }_{2}\left(3823\right)$

Using $9.0\text{}\text{}f{b}^{-1}$ 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 ${\chi }_{c1}\left(3872\right)\to \gamma {\psi }_{2}\left(3823\right)$. No signal is observed and the upper limit on the ratio of branching fractions $B\left({\chi }_{c1}\left(3872\right)\to \gamma {\psi }_{2}\left(3823\right),{\psi }_{2}\left(3823\right)\to \gamma {\chi }_{c1}\right)/B\left({\chi }_{c1}\left(3872\right)\to {\pi }^{+}{\pi }^{-}J/\psi \right)$ is set at 0.075 at the 90% confidence level. Our result contradicts theoretical predictions under the assumption that the ${\chi }_{c1}\left(3872\right)$ is the pure charmonium state ${\chi }_{c1}\left(2P\right)$.