The strong interaction strength of the first proton alignment in ¹⁵⁷Ho

Abstract

Two rotational bands have been observed in 157Ho which decay by a series of ten and eleven transitions and populate the yrast levels just above the first neutron backbend. These bands experience a gradual increase in alignment ( Delta i approximately 6h(cross)) over a large frequency range 0.25<or approximately=h(cross) omega <or approximately=0.55 MeV compared with the yrast configurations. This is interpreted as the first h11/2 proton alignment taking place with a very strong interaction strength.