Analysis of the ${\eta }_1(1855)$ as a $K{\bar{K}}_1(1400)$ molecular state

In this work, we study the radiative and strong decay of $S$-wave $K{\bar{K}}_1(1400)$ molecular state within the effective Lagrangians approach and find the relation between the $K{\bar{K}}_1(1400)$ molecular state and the newly observed ${\eta }_1(1855)$ state by comparing with the BESIII observation. The prediction indicates that the decay width can reach up to $182.97_{-3.50}^{+2.79}$ MeV, which can be confronted with the experimental data. If the ${\eta }_1(1855)$ could be $S$-wave $K{\bar{K}}_1(1400)$ molecular state, the $K{\bar{K}}^{\ast }\pi$ three-body decay provides the dominant contribution, not the $\eta {\eta }^{{}^{\mathrm{\prime }}}$ channel found in the experiment. In addition, the partial width for ${\eta }_1(1855)\to \gamma \varphi$ can reach up to $17.95_{-0.43}^{+0.21}$ KeV. Those results can be measured in future experiments and used to test the nature of the ${\eta }_1(1855)$.