Collective bands in 115I

The excited states of the I-115 nucleus have been studied by using in-beam gamma-ray spectroscopy with the Y-89 (Si-29, 3n) I-115 reaction at a beam energy of 108 MeV. The level scheme of I-115 was established by using gamma - gamma coincidence and gamma - gamma angular correlation analysis. In the present work, many collective bands built on the proton h(11/2), g(7/2), and d(5/2) were observed. Among them, an unfavored rotational band and a quasi-gamma band based on the pih(11/2) configuration was newly identified. A well-developed rotational band built on the 7/2(+) level was established up to I-pi = 47/2(+). This positive-collective band could be interpreted as coming from the pig(7/2) configuration at low spins. At higher spins above I-pi = 23/2(+), that band was found to be associated with the aligned three-quasiparticle configuration built on a proton in the g(7/2) orbital coupled to a pair of neutrons in the h(11/2) orbital.