Close-coupling calculations of transfer in collisions

Abstract

We present calculations of the cross sections for muon transfer in collisions within the framework of the quantal close-coupling approximation. The total internal wavefunction of the system is expanded in terms of atomic orbitals on each atomic centre. The appropriate Jacobi coordinates are used in the direct and rearrangement channels. A pseudostate representation of the continuum is also employed. The t-matrix elements are obtained from the solution of coupled Lippmann - Schwinger equations using the momentum space formulation. For the isotopic exchange calculations the basis consists of a large number of s and p type atomic states symmetrically distributed between direct and rearrangement channels. The present results are in agreement with existing calculations in the case of elastic scattering for collision energies above about 0.001 eV. In the case of the rearrangement process the agreement is satisfactory for collision energies greater than 10 eV.