Nuclear Exotic Structures, Exotic Decays and Near-Barrier Reactions

The reaction dynamics of weakly-bound nuclear systems at near-barrier energies is a compelling topic in nuclear physics. This review summarizes decades of experimental work by the Nuclear Reaction Group at the China Institute of Atomic Energy. Using transfer reactions with the distorted wave born approximation and asymptotic normalization coefficient analyses, we confirm the first excited neutron halo (13C) on the β-stability line and identified new halo states in 12B. Total reaction cross-section measurements revealed proton halo nuclei 27P and 29S, with core enlargement observed in 27P and 28P. We established conditions for halo formation and delineated the proton halo existence region. In two-proton emission studies, we observed 2He cluster emission from highly excited 17,18Ne and 28,29S, with 29S being the second such case internationally. In β-delayed decay, we discovered β2p emission in 22Si and determined its mass, observing isospin-symmetry breaking in 20Mg, 22Si, and 27S. Decay schemes for 27S and 26P addressed the 26Al abundance problem. For nuclear interactions, we investigated the 6He optical potential, finding the dispersion relation inapplicable for 6He + 209Bi, and developed notch and Bayesian methods to constrain uncertainties. For unstable nuclei, the proton drip-line systems 8B and 17F have been intensively studied via complete kinematics measurements of the 8B + 120Sn and 17F + 58Ni reactions, respectively. The results show that elastic breakup dominates for proton-halo 8B, while inelastic breakup prevails for 17F, with proton-rich nuclei exhibiting lower breakup probabilities than neutron-halo nuclei due to Coulomb effects. Fusion studies revealed sub-barrier enhancement in 17F + 58Ni from continuum couplings. We propose direct fusion–evaporation measurements with deflection systems integrated with breakup detection to disentangle complete and incomplete fusion channels.