The photoproduction of a Λ on is investigated by using the recently developed Saclay-Lyon amplitudes for the reaction and the single-particle wave functions from a relativistic mean-field model of nuclei and Λ hypernuclei. With the nuclear transition matrix elements taken from a shell-model calculation, the predicted bound-Λ production cross sections are close to the reaction data. The dependence of the predictions on the model of amplitudes has been investigated. The cross sections of quasifree processes leading to an unbound Λ are also calculated in a simple three-body model. The predicted cross sections of the inclusive reaction reproduce the energy dependence of the data up to 1.1 GeV, but overestimate the magnitude by a factor of about 2.2. We discuss the extent to which this overestimation can be understood in terms of medium effects on the propagation of the outgoing and Λ.
- Received 3 September 1997
- Published in the issue dated September 1998
© 1998 The American Physical Society