Study Of High Spin States In ～(126)I

The iodine nuclei (Z=53) in the mass A=120～130 region lie in a transitional region between the primarily spherical Sn (Z=50) nuclei and well-deformed Ce (Z=58) nuclei .They have relatively small deformations and γ–soft shapes. Previous experimental and theoretical investigations revealed that the excited states of iodine isotopes exhibit very rich and interesting nuclear properties. At higher spin, band termination was found in odd-A 113～¹²³I and doubly odd ^120,122,124I nuclei; at low spin, the coexistence of collectively prolate ( triaxiality parameter γ≈0°) and oblate (γ≈-60°) shapes have been identified in a number of iodine istopes. Recently, chiral symmetry breaking was found in ¹¹⁸I. These phenomena involve a lot of physics contents. With N increasing, these interesting phenomena may still occur. Experimentally, it is hard to populate the high-spin states of iodine nuclei (A>124) by fusion-evaporation reactions induced with heavy-ion projectiles (A>10). Therefore, γ-ray spectroscopic features of iodine isotope nuclei with relatively rich neutrons are still very fragmentary. This dissertation reports an investigation of high spin states in doubly-odd ¹²⁶I through ¹²²Sn (¹¹B,5n2p) fusion-evaporation reaction. These observations provide very deep insights into the nuclear structures. Excited states in odd-odd ¹²⁶I were populated through this reaction at beam energies of 55 and 60 MeV with beams provided by the HI-13...