Strong Neutron Pairing in core+4n Nuclei

Summary, in English

The emission of neutron pairs from the neutron-rich N=12 isotones C18 and O20 has been studied by high-energy nucleon knockout from N19 and O21 secondary beams, populating unbound states of the two isotones up to 15 MeV above their two-neutron emission thresholds. The analysis of triple fragment-n-n correlations shows that the decay N19(-1p)C18∗→C16+n+n is clearly dominated by direct pair emission. The two-neutron correlation strength, the largest ever observed, suggests the predominance of a C14 core surrounded by four valence neutrons arranged in strongly correlated pairs. On the other hand, a significant competition of a sequential branch is found in the decay O21(-1n)O20∗→O18+n+n, attributed to its formation through the knockout of a deeply bound neutron that breaks the O16 core and reduces the number of pairs.

• Author: A. Revel; F. M. Marqués; O. Sorlin; T. Aumann; C. Caesar; M. Holl; V. Panin; M. Vandebrouck; F. Wamers; H. Alvarez-Pol; L. Atar; V. Avdeichikov; S. Beceiro-Novo; D. Bemmerer; J. Benlliure; C. A. Bertulani; J. M. Boillos; K. Boretzky; M. J.G. Borge; M. Caamaño; E. Casarejos; W. N. Catford; J. Cederkäll; M. Chartier; L. Chulkov; D. Cortina-Gil; E. Cravo; R. Crespo; U. Datta Pramanik; P. Díaz Fernández; I. Dillmann; Z. Elekes; J. Enders; O. Ershova; A. Estradé; F. Farinon; L. M. Fraile; M. Freer; D. Galaviz; H. Geissel; R. Gernhäuser; P. Golubev; K. Göbel; J. Hagdahl; T. Heftrich; M. Heil; M. Heine; A. Heinz; A. Henriques; A. Knyazev
• Department/s: Department of Physics
• Publishing year: 2018-04-12
• Language: English
• Publication/Series: Physical Review Letters
• Volume: 120
• Issue: 15
• Links: http://dx.doi.org/10.1103/PhysRevLett.120.152504
• Document type: Journal article
• Publisher: American Physical Society
• Topic: Subatomic Physics
• Status: Published
• ISBN/ISSN/Other: ISSN: 0031-9007