Research On High Spin States In Doubly Odd ～(162) Ho And Signature Splitting Systematics Of The π H_11/2 Bands In Odd-Z Nuclei Around A～160

In recent years, as a good candidate to study the residual interaction between quasi-proton and quasi-neutron, people have paid more and more attention to the study in doubly odd nuclei. In A¹60 rare-earth region, research on the GM doublet has been done in many nuclei, that is helpful to the investigation of study in the residual p-n interaction. Recently, a series of systematic calculations in the framework of Two-Quasiparticle-Plus-Roter Model reveal that the well-known phenomenon of low-spin signature inverseon in deformed odd-odd nuclei is closely related to the residual p-n interaction. Hign spin states of odd-odd nucleu ¹⁶²Ho have been populated through fusion-evaporation ¹⁶⁰Gd(⁷Li,5n)¹⁶²Ho at a beam energy of 49MeV. The experiment is performed at the HI-13 Tandem Accelerator in the China Institure of Atomic Energy (CIAE). The detecting array consists of 11 HPGe detectors. The energy and efficiency of each detector are calibrated with standard radioactive source ¹⁵²Eu. After unfolding, the γ-γcoincidence events were sorted off-line into a symmetric two-dimentional E_γ-E_γmatrix, a asymmetric DCO ratio matrix, and two asymmetric ADO ratio matrices. By analyzing the gated spectrum of the E_γ-E_γmatrix carefully, there are more than 150 new γrays belonging to ¹⁶²Ho, which have been observed in the present work. The level scheme of ¹⁶²Ho has been established, with six bands and linking transitions. On the bases of excitation energy systematics, alignment additivity rule, ADO ratios, and comparisons of measured and theoretically expected B(M1)/B(E2) ratios, we summarize the experimental results as follows: 1). The yrast band is extended up to higher spin by several units( ), and the highest spin is 26 , which has been assigned configuration {Ï€hh h11/2[523]7/2-?νi13/2[642]5/2+}(KÏ€=6-); 2). The band that is referred to as a GM doublet with yrast band is constructed, confirming the results about the placements of the 141.5 and 179.8 keV reported previously; 3). The rotational band based on the ground-state is established, and the quasi-particle configuration is {Ï€h11/2[523]7/2-?νf7/2[523]5/2-}(KÏ€=1+); 4). Three new bands have been established. One constitutes the so-called GM doublet with the ground-state band, one is the high-K band assigned as {Ï€h11/2[523]7/2-?νh11/2[505]11/2-}(KÏ€=9+) configuration, and another one is probably based on the {Ï€h11/2[523]7/2-?νh9/2[521]3/2-}(KÏ€=5+) intrinsic structure; 5). The linking transitions from band 1 to band 2, from band3 to band 4 have been tentatively placed. By theoretical functions and mathematical methods, the empirical GM splitting energies( ?E GM) for the two GM doublets in 162Ho are obtained, which are relatively in good agreement with the theoretical predictions. The signature inversion phenomena in both high-K and low-K Ï€h11/2?νi13/2 bands has been studied, and the results are consistent with the well-known phenomenon of low-spin signature inversion in deformed odd-odd nuclei. In addition, it is probable the difference between the parallel coupling and the anti-parallel coupling of the intrinsic spins that causes the low-K band has larger anomalous signature splitting than the high-K band. Systematic features of signature splitting of Ï€h11/2 bands before backbending in odd proton nuclei around A¹60 have been investigated in this paper. The large region of deformation covered by these nuclei and the occupation of nearly every orbital in the h11/2 shell will reveal the...