# How do scientists measure the spin-parity of a resonance?

I have seen many plots and data tables which display the cross-section vs. center of mass energy for a particular nuclear reaction at a given angle. Here is an example.

You can see that there are a few 'humps', which are the resonances. Now I can [somewhat] see how one could obtain the excitation energy and partial width for a resonance, but how does one measure the spin-parity (J$^{\pi}$) of a resonance? I see in most of those plots and tables that the researchers have also obtained the respective spin-parities for their respective resonances, but I have no idea how one could arrive at that.

• You can't and don't get it from only the data plotted here. No time to write a full answer now. Feb 2 '15 at 17:56
• Oh I see. That's good to hear. Please get back to this when you can (I'll be very happy). Feb 2 '15 at 20:40

• Ah I see. Do you know of any links where I can read more about methods of obtaining the $J^{\pi}$ of resonances? Mar 2 '15 at 14:50