Spectroscopy along the N = Z line between mass 70 and 84

This thesis presents results from fusion-evaporation reaction experiments aimed to study nuclei in the N = Z region. Specifically, new results obtained for the ⁷⁰Br, ⁷⁰Kr, ⁷⁸Y and ⁸⁴Mo nuclei are presented. The ⁸⁴Mo experiment identified the excited states up to the 6⁺ state, and tentatively up to the 10⁺ state. In addition, other suitable reactions to populate the excited states in ⁸⁴Mo were investigated. Further measurements of higher-lying excited states are required to determine the cause of the absent or delayed backbending in ⁸⁴Mo. The recoil-β tagging method was used to study the excited states in the ⁷⁰Br, and ⁷⁸Y nuclei. Several new γ-ray transitions were observed from the decays of the excited states in the ⁷⁰Br nucleus. Moreover, the T = 1 band in ⁷⁰Br was extended up to the J^π = 10⁺ state. Multiple new excited states were also observed in the ⁷⁸Y nucleus, including a new J^π = 6⁺ state in the T = 1 band. The recoil-double-β tagging method was used for the first time to study the decays of the excited states in ⁷⁰Kr. Two γ rays were observed, which were assigned as the 2⁺ → 0⁺ and 4⁺ → 2⁺ transitions in ⁷⁰Kr. The experimental results on the ⁷⁰Kr, ⁷⁰Br, and ⁷⁸Y nuclei can be used to investigate the charge-symmetry and charge-independence characteristics of the strong nuclear interaction. Keywords: Isospin, Isospin-symmetry breaking, Proton-neutron pairing, Coulomb energy difference, Mirror energy difference, Triplet energy difference, Recoil-β tagging, Recoil-double-β tagging