I was reading about Regge radial trajectories for $\rho$ meson and I found that we have two given by the values of the orbital angular momentum, $L=0$ and $L=2$. With this part, I feel OK. But, when I try to understand how they know that $\rho(1450)$ is $2^3\,S_1$ and the next mass state $\rho(1700)$ is associated to $1^3\,D_1$, the first state in the $L=2$ trajectory, I become a mess!. So, please, anyone could tell me how they do the categorization?. Was it make on experimental parameters?
I'm not so familiar with the standard technics of characterization used in meson physics, so could you give some references. Thanks in advance!