Collective excitations in148Gd populated in thep p?-reaction on a radioactive target

Abstract

Collective excitations in the two-particle nucleus 14SGd up to 2.9 MeV have been investigated by the pp'-reaction at 25 MeV beam energy, and angular distributions have been analyzed with standard DWBA calculations. It is found that ~48Gd has larger octupole-than quadrupole collectivity in the energy range investigated. The 3strength distribution is in quantitative agreement with predicted results for the levels formed by the coupling of two valence particles to the ~46Gd core octupole phonon.

Shell model and octupole states in148Gd from in-beam experiments

“…We mention here that the recent (p,p') study [17] with a radioactive ~48Gd target has identified the 32 and 33 states, at 2.234 and 2.917 MeV, both within 20 keV of the predicted energy. III.3, reflecting the coupling to high-lying core excitations.…”

“…No other fp multiplet member was observed in the present experiments, but a 2.189 MeV 2 + state rather strongly excited with l=2 in pp' [17] and an/=4 state at 2.763 MeV are good candidates for the fp 2 + and 4 + levels. Moreover, the aK value and the angular distribution data for the 1058 keV 5 + ~ 6 + transition require > 70% E2 content, which gives strong independent support for the fp assignment.…”

“…States with excitation energy given in keV are from the present work, except the 2189 keV 2 + and 2763 keV 4 + vfT/2 P3/2 levels that were identified in pp' [17]. Unknown multiplet members are shown at schematic energies; the (f/) 3-to 9 states couple strongly to the f2 x 3-levels and lie at higher energies than shown here (cf.…”

“…Yet later, a 12-transition superdeformed E2 cascade was identified [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] in Ca-and Si-induced reactions but it is so far not connected to the low-lying yrast states. For completeness, we mention that detailed data on 70-m ~STb(2-) decay by Schus et al have been reported in the Nuclear Data Sheets [12], and that the low-lying ~SGd collective states were studied [17] in a (p, p') experiment with a radioactive target.…”