Equations for Four-Particle Scattering

Four-particle scattering equations are obtained that are analogous to the Lovelace or Alt-Grassberger-Sandhas equations in the three-particle case: They are equations whose kernel is connected after one iteration, in which the unknown quantities are the transition operators for the various elastic, inelastic, and rearrangement processes. The equations couple together only the transitions to the two-body channels, exactly as in the three-particle analogs, so that there are seven coupled integral equations, corresponding to the seven two-body channels (four of nucleon + triton type, and three of deuteron + deuteron type). Transition operators to the three- and four-body channels appear as integrals over the transition operators to the two-body channels.