A model for the calculation of the nuclear excitation function following muon capture in complex nuclei and of the ensuing emission is presented. The capturing nucleus is treated as consisting of quasifree nucleons moving in a momentum-dependent potential and having an effective nucleon-momentum distribution. The emission of protons, deuterons, $\alpha$ particles, and neutrons is calculated by considering both pre-equilibrium and compound-nucleus emission. The model accounts well for the observed charged particles emission rates from capturing nuclei over the wide range $23\le A\le 209$. The proton emission is shown to become mainly of pre-equilibrium nature for the heavier nuclei. The results for neutron emission are also in satisfactory agreement with experimentally measured multiplicities and spectra.

NUCLEAR REACTIONS Calculated probabilities of (${\mu }^{-}, \mathrm{pxn}$), (${\mu }^{-}, \alpha$) $E_{\mu }=0\mathrm{}$ reactions for various targets with $23<~A<~209$; inclusive and exclusive channels; pre-equilibrium emission; compound-nucleus emission; neutron multiplicities; nuclear excitation distribution following $\mu$ capture.

• Received 22 January 1980

DOI:https://doi.org/10.1103/PhysRevC.22.2135