Particle-hole excitations in the208Pb mass region

Abstract

Spectra, magnetic dipole moments and spectroscopic factors of a number of A = 205-209 nuclei as well as M1 transitions in 2~ are investigated in terms of large-scale shellmodel calculations which include lp-1 h excitations and for some nuclei 2p-2 h excitations. The calculated spectra agree well with the data. The calculated g-factors are in fair agreement with the data in most cases. The predicted strength for M1 transitions to low-lying states in 2~ is less than that obtained from previous calculations. Spectroscopic factors for l= 0 proton pick-up from 2~ and 2~ agree very well with recent experimental data from (e, e' p) reactions.

A microscopic model taking into account 2p 2h configurations in magic nuclei. Calculations ofM1 excitations

“…According to the lp lh approach, no M 1 resonance can exist if the p shell or sd shell is fully occupied in 160 and 4~ correspondingly. The M1 excitation calculations within the framework of the many-particle shell model [19,23,50] are rather complicated and it is difficult to extend them to all the nuclei.…”

Quadrupole moments and mean square charge radii in the bismuth isotope chain

“…The quadrupole moments of the even{N bismuth ground states studied in this work are compared to a shell model calculation in table 2. The moments were calculated with the PBPOP interaction [21] restricting the proton to the h 9=2 orbit and allowing neutron particles in the g 9=2 and i 11=2 orbits and neutron holes in the p 1=2 p 3=2 and f 5=2 orbits [22]. The eective charges for proton and neutrons were e =+1.27e and e =+0.9e.…”

The doubly-magic character of146Gd and its relation to208Pb

“…Therefore we will make use also of the results of a recent shell-model study on nuclei in the 2~ region [21]. In the latter calculations on A=205-209 the nuclei with A = 208 and 209 have been treated in an approach which is very similar to the present one for A= 146 and 147.…”