Speaker
Description
The region of proton-rich nuclei around the N=Z offers a rich testing
ground for various nuclear models. Rapid shape changes have been
observed between from prolate deformation in 76Kr to an oblate ground
state in 72Kr. Based on the comparison with its mirror nucleus 70Se, an
oblate shape is expected for 70Kr. Breaking of isospin symmetry as well
as the proximity to the proton drip line however, may lead to measurable
differences in the excitation energy spectrum as well as the quadrupole
collectivity of the A=70 mirror pair 70Kr and 70Se. 70Kr has been
studied at the RIBF facility using Coulomb excitation and neutron
removal reactions using the BigRIPS fragment separators to select
70-72Kr beams. Reaction products were identified in the ZeroDegree
spectrometers, while emitted gamma-rays were detected in the DALI2
array. Detailed spectroscopic information on 70Kr and measurements of
the B(E2) value will be presented and discussed in comparison to the
mirror nucleus 70Se and theoretical calculations. These results give
important insights in the evolution of shape coexistence and isospin
symmetry across the N=Z line.
