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High-spin states of ¹⁶⁰Tm are studied via in-beam gamma-ray spectroscopy. Previously known rotational bands are confirmed. These bands feed into low-lying states which are enriched in this work. A four-quasiparticle band with configuration of πg_7/2 ⊗ νh_9/2 ⊗ ν(i_13/2)² is established. Signature splitting features of πh_11/2⊗νi_13/2 and πh_11/2⊗νh_9/2 bands are presented.

We have performed shell model calculations for neutron deficient even ^102-108Sn and odd ^103-107Sn isotopes in sdg_7/2h_11/2 model space using two different interactions. The first set of interaction is due to Brown et al. and second is due to Hoska et al. The calculations have been performed using doubly magic ¹⁰⁰Sn as core and valence neutrons are distributed over the single particle orbits 1g_7/2, 2d_5/2, 2d_3/2, 3s_1/2 and 1h_11/2. In more recent experimental work for ¹⁰¹Sn [I. G. Darby et al., Phys. Rev. Lett.105 (2010) 162502], the g.s. is predicted as 5/2⁺ with excited 7/2⁺ at 172 keV. We have also performed another two set of calculations by taking difference in single particle energies of 2d_5/2 and 1g_7/2 orbitals by 172 keV. The present state-of-the-art shell model calculations predict fair agreement with the experimental data. These calculations serve as a test of nuclear shell model in the region far from stability for unstable Sn isotopes near the doubly magic ¹⁰⁰Sn core.

The interaction strength between chiral doublet bands is studied using the two-band mixing picture and the particle rotor model (PRM). The present calculations indicate that the interaction strength between chiral doublet bands is equal to zero for the ideal case of the configuration with γ = 30°, and the interaction strength becomes larger as γ deviates from 30°. For γ = 15° or 45°, the average interaction strength is approximately 180 keV in the chiral region.

The symmetric three center shell model has been constructed in order to account for the transition of the level scheme of one parent nucleus towards three equal spherical fragments. The model calculate the energy levels using a three center oscillator potential for partially overlapped nuclei. The oscillator levels and the spin-orbit and l² terms are dependent on the distance between the centers of the side fragments, thus on the elongation of the ternary configuration. At the end the independent level schemes of three separated spherical nuclei are obtained. Calculations are applyied to the splitting of ¹⁴⁴Nd into three ⁴⁸Ca spherical systems.

An experiment aiming to search for new isomers in the region of proton emitter ¹⁵¹Lu was done in the Accelerator Laboratory of the University of Jyväskylä (JYFL). Rich information on ¹⁵¹Lu and ^151mLu has been obtained from our data analysis. In this work, we revisit the level scheme of ¹⁵¹Lu by using the proton-tagging technique and measure the half-lives of ¹⁵¹Lu and ^151mLu are 82.8±0.7 ms and 15.4±0.8 μs, respectively.

The high-spin states in ⁸⁹Zr have been studied by in-beam γ-ray spectroscopy using the heavy ion fusion evaporation reaction ⁷⁶Ge(¹⁹F,p5n)⁸⁹Zr reaction at a bombarding energy of 80 MeV. The level scheme of ⁸⁹Zr has been constructed up to . The large-basis shell model code OXBASH was employed to analyze the level structure of ⁸⁹Zr. The results of shell-model calculation are in good accordance with the experiment.

The high-spin states in the odd-A ⁸⁷Sr were populated by fusion-evaporation reaction ⁸²Se(⁹Be, 4n)⁸⁷Sr at a beam energy of 46 MeV. The positive-parity band for ⁸⁷Sr is extended up to about 7.4 MeV excitation energy and spin values around 31/2ħ in the addition of 39 new transitions. The possible condfigurations of the positive parity band are suggested by comparison with the isotope ⁸⁵Sr and the alignment value of experiment.

High spins states in ⁸⁶Sr were populated by the reaction ⁸²Se (⁹Be, 5n) ⁸⁶Sr. γ - γ coincidence measurements along with investigation of directional correlation ratios(DCO) were utilized to establish the extended level scheme of ⁸⁶Sr from 13ħ up to 20ħ. Twenty-nine new transitions were found in ⁸⁶Sr. The configurations of ⁸⁶Sr were generally specified tentatively by comparing neighboring nuclei systematically.