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

## TL;DR

This paper analyzes the resonance contributions with different quantum numbers to the decay process of J/psi into gamma and phi phi, using BESIII data to extract coupling constants, resonance masses, and branching fractions.

## Contribution

It provides a detailed dynamical analysis of resonance contributions in J/psi decay, including extraction of effective couplings and resonance parameters from experimental data.

## Key findings

- Resonance masses and coupling constants were determined.
- Branching fractions for X resonances decaying to phi phi were evaluated.
- Photon angular distributions were obtained from the fits.

## Abstract

The dynamics of the $J^{PC}=0^{-+}$, $0^{++}$, and $2^{++}$ resonance contributions to the decay $J/\psi\to\gamma X(J^{PC})\to\gamma\phi\phi$ 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 $X(J^{PC})\to\phi\phi$ and masses of $X(J^{PC})$ resonances are found from the fits. They are used for evaluation of the branching fractions $B_{X(J^{PC})\to\phi\phi}$, relative branching fractions $B_{J/\psi\to\gamma X(J^{PC})\to\gamma\phi\phi}$, and for obtaining the photon angular distributions.