Sensitive Criterion For Chirality; Chiral Doublet Bands In ~(104)Rh_(59)

摘要

A particle plus triaxial rotor model was applied to odd-odd nuclei in the A ～ 130 region in order to study the unique parity πh_(11/12)directXvh_(11/2) rotational bands. With maximum triaxiality assumed and the intermediate axis chosen as the quantization axis for the model calculations, the two lowest energy eigenstates of a given spin have chiral properties. The independence of the quantity S(I) on spin can be used as a new criterion for chirality. In addition, a diminishing staggering amplitude of S(I) with increasing spin implies triaxiality in neighboring odd-A nuclei. Chiral quartet bases were constructed specifically to examine electromagnetic properties for chiral structures. A set of selection rules unique to chirality was derived. Doublet bands built on the πg_(9/2)directXvh_(11/2) configuration have been discovered in odd-odd ~(104)Rh using the ~(96)Zr(~(11)B, 3n) reaction. Based on the discussed criteria for chirality, it is concluded that the doublet bands observed in ~(104)Rh exhibit characteristic chiral properties suggesting a new region of chirality around A ～ 110. In addition, magnetic moment measurements have been performed to test the πh_(11/2)directXvh_(11/2) configuration in ~(128)Cs and the πg_(9/2)directXvh_(11/2) configuration in ~(104)Rh.