Электронный каталог

Статья

Lou, J.
Experimental Progress of Shell Evolution Studies in Light Neutron-Rich Nuclei Via Single-Nucleon Transfer Reactions / J.Lou, H.Zhu, G.Kaminski, [a.o.]. – Text : electronic // Chinese Science Bulletin. – 2026. – Vol. 71, No. 4. – P. 865-873. – URL: https://doi.org/10.1360/CSB-2025-5436. – Bibliogr.: 48.

Single-nucleon transfer reactions, including both stripping (e.g., (d, p), (d, n)) and pickup (e.g., (p, d), (n, d)) processes, provide a fundamental experimental approach for investigating single-particle structures of atomic nuclei. This paper reviews the historical progression of single-nucleon transfer reaction studies, with particular emphasis on their critical role in extracting essential nuclear structure parameters, such as spectroscopic factors, spin-parity, and effective single-particle energies. Special attention is paid to recent progress of shell evolution phenomena in neutron-rich Be, B, and C isotopes, specifically addressing the disappearance of the conventional N = 8 magic number and the emergence of new shell closures at N = 14, 16, and Z = 6. The theoretical framework for direct nuclear reactions was established by Oppenheimer-Phillips, Bethe, and Serber, who successfully interpreted the anomalous energy dependence of deuteron-induced reaction cross-sections and clearly differentiated direct reaction mechanisms from compound nuclear processes. The theoretical evolution from the plane-wave Born approximation (PWBA) to the distorted-wave Born approximation (DWBA) significantly enhanced the quantum mechanical treatment of transfer reactions, facilitating accurate extraction of nuclear structure parameters from angular distribution analyses. Of particular significance, Macfarlane and French introduced the foundational concepts of spectroscopic factors and sum rules, which revealed the quenching phenomenon of spectroscopic factors that are related to nuclear many-body correlations. Recent experimental advances utilizing radioactive ion beams have yielded important insights. Complementary measurements of &sup(2)H(&sup(11)Be, p)&sup(12)Be demonstrated a predominant d-wave intruder configuration (57%) in &sup(12)Be, in striking contrast to the s-wave dominance (approximately 80%) observed in &sup(11)Be. The &sup(2)H(&sup(16)C, p)&sup(17)C reaction provided conclusive evidence for s1/2-d5/2 orbital degeneracy in &sup(17)C, supporting the weakening of the N = 14 shell closure in carbon isotopes. These findings demonstrate the unique capability of single-nucleon transfer reactions in elucidating shell evolution in exotic nuclei. To address controversial questions regarding the persistence of the Z = 6 magic number and N = 16 subshell closure, we have developed a Large Acceptance Charged-particle detector array at Peking University (LACPU). The large acceptance of LACPU enables simultaneous measurement of multiple reaction channels with high detection efficiency, including (d, p), (d, &sup(3)He), and (d, t). Its first experiment with &sup(14−16)C beams can determine proton occupancy in 0p1/2 orbitals and the ESPEs of 0p&sub(1/2), 0p&sub(3/2), 0d&sub(3/2) orbitals, providing evidence for Z = 6 and N =16 shell closure. Future investigations will employ the Active Target Time Projection Chamber (AT-TPC) to study unbound states in 10Li, offering new opportunities to examine the breakdown of conventional magic number N = 8. In conclusion, single-nucleon transfer reactions, when combined with next-generation accelerator facilities (such as HIAF and BRIF) and advanced detection systems (including LACPU and AT-TPC), will continue to provide unparalleled insights into shell evolution phenomena in exotic nuclei



Спец.(статьи,препринты) = С 341.2 - Свойства атомных ядер
ОИЯИ = ОИЯИ (JINR)2026