Dynamical analysis of the $X$ resonance contributions to the decay $J/\psi \to \gamma X\to \gamma \varphi \varphi$

Abstract

The dynamics of the $J^{PC}=0^{-+}$, $0^{++}$, and $2^{++}$ resonance contributions to the decay $J/\psi \to \gamma X(J^{PC})\to \gamma \varphi \varphi$ is analysed using the data obtained by BESIII collaboration. The effective coupling constants parameterising invariant amplitudes of the transitions $J/\psi \to \gamma X(J^{PC})$ and $X(J^{PC})\to \varphi \varphi$ and masses of $X(J^{PC})$ resonances are found from the fits. They are used for evaluation of the branching fractions $B_{X(J^{PC})\to \varphi \varphi }$, relative branching fractions $B_{J/\psi \to \gamma X(J^{PC})\to \gamma \varphi \varphi }$, and for obtaining the photon angular distributions.

Comments: 11 pages, 8 figures