Structure of high spin states in "1"0"4Sn - E2 and E3 polarization of the "1"0"0Sn core

High spin states in "1"0"4Sn were identified in the reaction "5"8Ni("5"0Cr,2p2n) at 200 MeV and 205 MeV beam energies. The #gamma#-ray energies, intensities, multipolarities, and lifetimes of high spin states were measured with the GASP spectrometer array in combination with a plunger apparatus by means of the recoil distance Doppler shift method. The deduced level scheme and transition probabilities are compared to the results of large-scale shell model calculations using three independent two-body interactions. The agreement of the level energies is satisfactory, except for a cascade of dipole transitions at high spins. The general good agreement found for E2 transition strengths implies a large effective neutron polarization charge. The shell-model calculations do not account for the measured enhanced E3 transitions for which a core excited octupole phonon admixture is indicated. (orig.)Available from TIB Hannover: RO 801(98-18) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Present status and future aspects of nuclear structure close to "1"0"0Sn

The present status of experimental approach to "1"0"0Sn in the spectroscopy of excited states is landmarked by the T_z=3/2 nuclei between "9"5Pd and "1"0"1In and the T_z=1 nuclei "9"4Pd and "9"8Cd. The detection limits with Pre-EUROBALL #gamma#-arrays and ancillary detectors are below the 10"-"5 level of the total fusion - evaporation residue cross section. A large scale shell model analysis of the existing data reveals the shell structure at "1"0"0Sn, which shows a remarkable similarity to "5"6Ni. Evidence for an increasing proton-neutron interaction in approaching the N=Z line is deduced from high spin isomers and spherical yrast lines. The effective E2 operator for protons and neutrons and implications for a low lying particle-hole (ph) E2 excitation in "1"0"0Sn are discussed. (orig.)SIGLEAvailable from FIZ Karlsruhe / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman