Study of the radiative decay J/ψ → η + γ in light cone sum rules

Abstract At present, there are many experimental and theoretical results for J / ψ → η c + γ process, while the results are inconsistent based on different methods and considerations. In this paper, the light cone sum rules method is used in studying the radiative decay J / ψ → η c + γ . We give the transition form factor of this process based on the leading twist distribution amplitude of η c meson, with this form factor further obtain the decay width. Our result is consistent with those of other sum rules. A comparison of our result with others' about the decay width is also presented.