II. Physikalisches Institut der Universität Heidelberg, Germany
II. Institut für Experimentalphysik der Universität Hamburg, Germany
Abstract:
In a nuclear two-stage reaction proceeding through excited states of an unstable intermediate system, rescattering can occur between two of the three outgoing particles as a special type of final-state interaction (“proximity scattering”). The probability for proximity scattering increases with a decreasing lifetime of the intermediate state. Correlations between protons and neutrons from the reaction 40Ca(d, np)40Ca were measured at a bombarding energy of 5.80 MeV and a neutron emission angle of 70°. The results are compared with a quantal calculation of the cross section for this process. A width Γ = 50±20 keV for the excited state at 3.46 MeV in 41Sc has been deduced from this comparison. Apparent discrepancies between the Γ-values obtained by this method and by a classical prediction for the proximity scattering probability are discussed.