The g-factors and magnetic rotation in ⁸²Rb

The g-factors of the intra-band states 12, 13, 14, 15 in a magnetic-rotational band built on the 11 state in ⁸²Rb are measured for the first time by using a transient magnetic field-ion implantation perturbed angular distribution (TMF-IMPAD) method. The magnetic-rotational band in ⁸²Rb is populated by the ⁶⁰Ni(²⁷Al,4pn)⁸²Rb reaction, and the time-integral Larmor precessions are measured after recoil implantation into a polarized Fe foil. The calculation of g-factors is also carried out in terms of a semi-classical model of independent particle angular momentum coupling on the basis of the four-quasiparticle configuration \pi ( g_9 / 2 )^2 \otimes \pi (p_3 / 2 ,f_5 / 2 ) \otimes \nu ( g_9 / 2 ). The measured and calculated g-factors are in good agreement with each other. The g-factors and deduced shear angles decrease with the increase of spin along the band. This clearly illustrates the shear effect of a step-by-step alignment of the valence protons and neutrons in magnetic rotation. The semi-classical calculation also shows that the alignment of the valence neutron angular momentum is faster than that of the valence protons, which results in a decrease of g-factors with increasing spin. The present results provide solid evidence of the shear mechanism of magnetic rotation.