During 4$\pi$ photoproduction in reaction of the $\rho'$ decay:
$$\rho'\rightarrow \pi^+\pi^-\pi^+\pi^-$$
I have a intermediate two-body decay state when $\rho_0\rightarrow \pi^+\pi^-$.
This allows us to check $\rho_0$ via determining of the decay angle for rest frame of $\rho_0$.
During 4$\pi$ photoproduction in reaction of the$\rho'$ decay:
I have a intermediate two-body decay state when$\rho_0\rightarrow \pi^+\pi^-$ .
This allows us to check$\rho_0$ via determining of the decay angle for rest frame of $\rho_0$ .