Nuclear spectroscopy in mass 40 region

Nuclei in the mass 40 region exhibit interesting phenomena related to nuclear structure. In the neutron-rich region, the structural changes have been extensively investigated to provide the understanding of "Island of inverstion". In high-spin states, investigations on superdeformed bands provide the structural information in the excited states. The experimental studies of this region could also provide important data set for different theoretical models. In this sense, the region could be one of unique fields to investigate the nuclear properties by changing the number of protons/neutrons and excited levels. In this presentation, the recent research activities in the mass 40 region will be highligted. After the overview, possible future in-beam gamma-ray experiments with highly-effieicnt position-sensitive gamma-ray detectors will be discussed.