Collectivity of neutron-rich carbon isotopes and the emergence of proton magic number

点击翻译按钮获取中文摘要

We have observed dissimilar response to perturbation of the protons and neutrons in the neutron-rich carbon isotopes ^<16,18>C, hitherto unobserved in the atomic nuclei close to the stability line. This phenomenon is beyond the common knowledge of nuclear physics, which was formulated mainly from studies on nuclei in the neighborhood of stability line. While some theories have attributed this anomaly to emergence of a new proton magic number, i.e. proton number 6, in the neutron-rich isotopes ^<16,18>C, it remains to be proven whether the new proton magic number does emerge. To examine this new-proton-magic-number hypothesis, and to explore possibility of other neighboring nuclei showing similar behavior, we have developed a new experimental method to determine the proton distribution radii.