Neutron-hole strength distributions in heavy nuclei: (I). The reactions 124, 130Te( 3He, α) 123, 129Te and 122, 124, 130Te(p, d) 121, 123, 129Te

Abstract

Neutron-hole strengths corresponding to orbits near and well below the Fermi surface in the 121, 123, 129Te isotopes have been observed in high resolution studies of the ( 3He, α) and of the (p, d) reactions at 70 and 42 MeV bombarding energy, respectively. Complete angular distributions have been obtained in the ( 3He, α) experiments whereas a few angles were recorded in the case of (p, d) reactions. Several new levels are observed up to 3 MeV excitation energy in the 121, 123, 129Te isotopes. A detailed analysis of the results from the two reactions has allowed rather unambiguous l determination of the transferred angular momentum, and spectroscopic factors have been extracted for the observed levels. A strong fragmentation of the 2d 5/2 and 1g 7/2 hole strengths is evidenced. At higher excitation energy, the 1g 9/2 inner-hole strength is still observed as a giant-resonance-like structure whose excitation energy and width increase with mass number. About 40 to 60 % of the total l = 4 hole strength is found to lie in the gross structure region (4–10 MeV). The results of the analysis are compared to the theoretical predictions of the quasiparticle-phonon coupling nuclear model.