The β-decay of 70Kr into 70Br: Restoration of the pseudo-SU(4) symmetry

The β-decay of the even-even nucleus 70Kr with Z=N+2, has been investigated at Radioactive Ion Beam Factory (RIBF) RIKEN Nishina Center using BigRIPS fragment separator, ZeroDegree Spectrometer, WAS3ABI implantation station and EURICA HPGe cluster array. Fifteen γ-rays associated into 70Br have identified for first time, defining ten populated states below Eexc=3300 keV. half-life was derived increased precision found to be t1/2=45.19±0.14 ms. β-delayed proton emission probability also determined as εp=0.545(23)%. An increase in β-strength yrast 1+ state comparison heaviest Z=N+2 system studied so far (62Ge decay) is observed that may indicate np correlations T=0 channel. strength deduced from results interpreted terms proton-neutron quasiparticle random-phase approximation (pnQRPA) a schematic model includes isoscalar isovector pairing addition quadrupole deformation. application this last indicates an approximate realization pseudo-SU(4) symmetry system.