Quasifree kaon photoproduction on nuclei

Investigations of the quasifree reaction A(gamma, KY)B are presented in the distorted wave impulse approximation (DWIA). For this purpose, we present a revised tree-level model of elementary kaon photoproduction that incorpor ates hadronic form factors consistent with gauge invariance, uses SU(3) val ues for the Born couplings and uses resonances consistent with multichannel analyses. The potential of exclusive quasifree kaon photoproduction on nuc lei to reveal details of the hyperon-nucleus interaction is examined. Detai led predictions for the coincidence cross section, the photon asymmetry, an d the hyperon polarization and their sensitivities to the ingredients of th e model are obtained for all six production channels. Under selected kinema tics these observables are found to be sensitive to the hyperon-nucleus fin al-state interaction. Some polarization observables are found to be insensi tive to distortion effects, making them ideal tools to search for possible medium modifications of the elementary amplitude. (C) 2001 Elsevier Science B.V. All rights reserved.