Trapping effect and high-lying single-particle modes - art. no. 064321

The phenomenon of trapping of states is studied in the case of high-lying s tates with large angular momentum in the odd-A nucleus Pb-209. The interact ion of the single-particle mode with more complex states is calculated in t he framework of the quasiparticle-phonon model while the coupling to the co ntinuum is included by means of the projection operator method. The results obtained show a reduction of the spreading of the single-particle strength under the influence of the coupling to the continuum: the strength is conc entrated on a few collective states while the remaining states are decouple d from the continuum (trapped). The results are compared with the case wher e continuum coupling is switched off. The influence of the continuum on the nuclear structure should be visible ill nucleon transfer reactions. [S0556 -2813(99)01812-9].