Generalized neutron particle-hole states in the N = 82 isotone 142Nd

Abstract

Angular distributions for the inelastic proton decay of the two lowest isobaric analogue resonances in 143Pm ( J π = 7 2 − , 3 2 − ) have been measured. Proton decay widths and excitation energies for levels in 142Nd between E x = 3 MeV and 5 MeV are deduced. Most of the observed levels can be interpreted as generalized neutron particle-hole (GNPH) states, a concept to which physical significance has been given by a similar experiment on 140Ce. Level spacings of the GNPH states as well as partial widths and angular distributions of decay protons from corresponding J π = 7 2 − and 3 2 − resonances are found similar for the different N = 82 isotones. The wave functions of four prominent states in 142Nd are determined in terms of GNPH configurations | lj −1, J π 〉 with lj = d 3 2 , s 1 2 , d 5 2 and J π = 7 2 − and 3 2 − . The wave functions of these states are similar to those of corresponding states in 140Ce. The spin splitting of the lowest GNPH configuration ¦d 3 2 − , 7 2 −ĭs identical for both N = 82 nuclei within the uncertainties of the analysis. This shows that the interaction among GNPH configurations depends only weakly on the number of protons. This fact is used to assign spins 1 − and 2 − to states containing appreciable amounts of the configuration | s 1 2 − , 3 2 − 〉