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

• DOI: 10.1016/j.physletb.2022.137123
• Publication Date: 2022-04-27T15:42:29Z
• Authors: A. Vitéz-Sveiczer; A. Algora; A.I. Morales; B. Rubio; G.G. Kiss; P. Sarriguren; P. Van Isacker; G. de Angelis; F. Recchia; S. Nishimura; J. Agramunt; V. Guadilla; A. Montaner-Pizá; S.E.A. Orrigo; A. Horváth; D. Napoli; S. Lenzi; A. Boso; V.H. Phong; J. Wu; P.-A. Söderström; T. Sumikama; H. Suzuki; H. Takeda; D.S. Ahn; H. Baba; P. Doornebal; N. Fukuda; N. Inabe; T. Isobe; T. Kubo; S. Kubono; H. Sakurai; Y. Shimizu; C. Sidong; B. Blank; P. Ascher; M. Gerbaux; T. Goigoux; J. Giovinazzo; S. Grévy; T. Kurtukián Nieto; C. Magron; W. Gelletly; Zs. Dombrádi; Y. Fujita; M. Tanaka; P. Aguilera; F. Molina; J. Eberth; F. Diel; D. Lubos; C. Borcea; E. Ganioglu; D. Nishimura; H. Oikawa; Y. Takei; S. Yagi; W. Korten; G. de France; P. Davies; J. Liu; J. Lee; T. Lokotko; I. Kojouharov; N. Kurz; H. Shaffner; A. Petrovici
• Keywords: Isovector; Yrast; Isoscalar; Radioactive decay; Decay energy

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.