Non-Dynamical Structure of Photoproduction Processes

This paper summarizes those general properties of photoproduction processes which are independent of the interactions among particles. The two types of reactions considered in detail are $\gamma +\frac{1}{2}\to s+\frac{1}{2}$ and $\gamma +\frac{1}{2}\to s+\frac{3}{2}$, where ½ and $\frac{3}{2}$ denote particles with spins ½ and $\frac{3}{2}$, respectively, and $s$ denotes a particle with an arbitrary integer spin $s$. The first of these reactions is synthesized from the reactions $\gamma +0\mathrm{}\to 0+0$, $0+\frac{1}{2}\to 0+\frac{1}{2}$, and $0+0\to s+0\mathrm{}$. First the observable structure of these constituent reactions is derived, and then the composite structure is obtained. Detailed results for the observables are given for $s=0, 1, \mathrm{and} 2$, and experiments designed to determine spin and parity are listed. The reaction $\gamma +\frac{1}{2}\to s+\frac{3}{2}$ is similarly composed of $\gamma +0\mathrm{}\to 0+0$, $0+\frac{1}{2}\to 0+\frac{3}{2}$, and $0+0\to s+0\mathrm{}$. Some results for this reaction are also tabulated. Finally, as a specific application of the above results, a method is suggested to determine the contribution of certain corrections to the static theory of pion photoproduction from nucleons. The whole paper is an application of the general nondynamical theory of particle reactions with arbitrary spins which was recently developed by the authors.