Isomeric states in neutron-rich nuclei near N=40

Neutron-rich nuclei in the vicinity of the N=40 island of inversion are characterized by shell evolution and exhibit deformed ground states. In several nuclei isomeric states have been observed and attributed to excitations to the intruder neutron 1g9/2 orbital. In the present paper we searched for isomeric states in nuclei around N=40,Z=22 produced by projectile fragmentation at the Radioactive Isotope Beam Factory. Delayed γ rays were detected by the Euroball RIKEN Cluster Array germanium detector array. High statistics data allowed for an updated decay scheme of V60. The lifetime of an isomeric state in V64 was measured for the first time in the present experiment. A previously unobserved isomeric state was discovered in Sc58. The measured lifetime suggests a parity changing transition, originating from an odd number of neutrons in the 1g9/2 orbital. The nature of the isomeric state in Sc58 is, thus, different from isomers in the less exotic V and Sc nuclei.