Excited-state one-neutron halo nuclei within a parallel momentum distribution analysis

The possibility for the existence of 1-neutron and 2-neutron halo nuclei through the decay of even-even nuclei 270-316116, 272-318118 and 278-320120 in the super-heavy region is studied within the frame work of the Coulomb and Proximity Potential Model (CPPM). Halo structure in neutron rich nuclei with Z<=20 is identified by calculating the neutron separation energies and on the basis of potential energy considerations. The 1n + core configuration of proposed 1-neutron halo nuclei between z=10 and Z=20 is found shifted to 2n + core configuration in higher angular momentum states. The calculation of half-life of decay is performed by considering the proposed halo nuclei as spherical cluster and as deformed nuclei with a rms radius. Except for 15C, the half-life of decay is found decreased when the rms radius is considered. Only the 1-neutron halo nuclei 26F and 55Ca showed half-lives of decay which are less than the experimental limit. None of the proposed 2-neutron halo nuclei have shown a half-life of decay lower than the experimental limit. Also, the probability for the emission of neutron halo nuclei is found to be less in super-heavy region when compared with the clusters of same isotope family. Further, neutron shell closure at neutron numbers 150, 164 and 184 is identified form the plot of log10 T1/2 verses the neutron number of parents. The plots of Q-1/2 verses log10 T1/2 and -ln P verses log10 T1/2 for various halo nuclei emitted from the super-heavy elements are found to be linear showing that Geiger-Nuttall law is applicable to the emission of neutron halo also.

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Influence of halo single-neutron transfer on near barrier $$^{15}$$C + $$^{12}$$C total fusion

The European Physical Journal A ◽

10.1140/epja/s10050-021-00476-x ◽

2021 ◽

Vol 57 (5) ◽

Author(s):

N. Keeley ◽

K. W. Kemper ◽

K. Rusek

Keyword(s):

Cross Section ◽

Fusion Cross Section ◽

Transfer Reactions ◽

Halo Nuclei ◽

Neutron Halo ◽

Neutron Transfer ◽

Model Calculations ◽

Single Neutron ◽

Barrier Penetration ◽

Total Fusion

AbstractA recent comparison of the average fusion cross section, $$\left\langle \sigma _\mathrm {F}\right\rangle $$ σ F , for energies just above the Coulomb barrier for the $$^{12-15}$$ 12 - 15 C + $$^{12}$$ 12 C systems found that the behaviour as a function of projectile neutron excess could not be satisfactorily explained by static barrier penetration model calculations and suggested that the neutron dynamics plays an important rôle. In this work we demonstrate that the ($$^{15}$$ 15 C,$$^{14}$$ 14 C) single neutron transfer has a significant influence on the above barrier $$^{15}$$ 15 C + $$^{12}$$ 12 C total fusion, although not quite in the way expected since it leads to a reduction in the cross section, contrary to the trend in the measured $$\left\langle \sigma _\mathrm {F}\right\rangle $$ σ F . However, this result underlines the danger of ignoring the effect of neutron transfer reactions on fusion in systems involving neutron halo nuclei.

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