Abstract
The hypernuclear spectrum excited in the weakly interacting electromagnetic production process is theoretically surveyed. Plane wave impulse approximated multiple-scattering calculations for hypernuclear formation from , , and targets are presented for a wide range of lab and excitation energies. Excitation energies and transition densities are calculated within a lambda-particle, proton-hole model using Woods-Saxon basis wave functions. The transition operator is constructed using the free (bare) amplitudes for the elementary process which are evaluated from Feynman diagrams including both strange meson (K,K*) and baryon () exchange. These amplitudes are dominated by and scalar K exchange; however, effects from and vector K* exchange are found to be significant even near threshold. The hypernuclear selective excitation is documented in detail for . Transitions to unnatural parity states and substitutional states with medium to high spin are predicted to be strong. Because of large momentum transfer (≥200 MeV/c), the (, K) reaction is highly quasielastic and a low, roughly 0.1, "sticking probability" is estimated using an approximate hypernuclear sum rule. The excitation process is sensitive to the interior as cross section calculations for involving bound , , , and configurations, unrestricted by the Pauli exclusion principle, reveal markedly different signatures. Cross section sensitivity is also investigated and discussed for off-shell amplitude effects, variations in the -nucleus spin-orbit interaction, and different sets of phenomenological coupling constants which equivalently describe the process. Finally, estimates for electroproduction, , are also presented and discussed. Both photoproduction and electroproduction cross sections are calculated to be measurably large for the beam energies, 1 to 3 GeV, of proposed intense electron accelerators.
NUCLEAR REACTIONS Kaon photoproduction and hypernuclear formation. Theoretical survey of for , , and . Plane wave impulse approximation and particle-hole wave functions. Investigation of cross section sensitivity to theoretical uncertainties. Application of hypernuclear sum rule. Electroproduction hypernuclear cross section estimates.
- Received 7 January 1983
DOI:https://doi.org/10.1103/PhysRevC.28.1668
©1983 American Physical Society