Rescattering contributions to the photoproduction of kaons from the deuteron

Abstract

A model is developed for the reaction $\ensuremath{\gamma}+d\ensuremath{\rightarrow}{K}^{+}+\ensuremath{\Lambda}+n$ that includes both impulse and rescattering contributions. Most of the well-established resonances of spins $\frac{1}{2}$ and $\frac{3}{2}$ below $1.9\phantom{\rule{0.3em}{0ex}}\text{GeV}$ are incorporated in the model. Initial estimates for the relevant coupling strengths are extracted from empirical information and SU(3) symmetry relations. For certain resonances, these initial estimates are modified to bring the cross sections calculated for certain elementary processes related to the rescattering terms in rough qualitative agreement with the empirical cross sections for these processes. For the ${N}^{*}$ and $\ensuremath{\Delta}$ resonances included in the model, off-shell width extrapolations are obtained by treating the energy and momentum dependence of each decay channel separately. Since the main intent of the study is to ascertain the importance of the rescattering terms in the reaction amplitudes, no attempt has been made to include final state correlations. To represent the initial state, a nonrelativistic deuteron wave function is employed. Results are presented for the differential cross section in the deuteron rest frame at fixed kaon energy and angle. The results indicate that rescattering contributions to the photoproduction of kaons from the deuteron may be significant over a wide kinematical range.