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arXiv · 1906.07623

Deformed shell effects in $^{48}$Ca+$^{249}$Bk quasifission fragments

K. Godbey·A. S. Umar·C. Simenel
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Abstract

Background: Quasifission is the main reaction channel hindering the formation of superheavy nuclei (SHN). Its understanding will help to optimize entrance channels for SHN studies. Quasifission also provides a probe to understand the influence of shell effects in the formation of the fragments. Purpose: Investigate the role of shell effects in quasifission and their interplay with the orientation of the deformed target in the entrance channel. Methods: $^{48}$Ca$+^{249}$Bk collisions are studied with the time-dependent Hartree-Fock approach for a range of angular momenta and orientations. Results: Unlike similar reactions with a $^{238}$U target, no significant shell effects which could be attributed to $^{208}$Pb "doubly-magic" nucleus are found. However, the octupole deformed shell gap at $N=56$ seems to strongly influence quasifission in the most central collisions. Conclusions: Shell effects similar to those observed in fission affect the formation of quasifission fragments. Mass-angle correlations could be used to experimentally isolate the fragments influenced by $N=56$ octupole shell gaps.

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K. Godbey, A. S. Umar, C. Simenel. 2019-06-18. Deformed shell effects in $^{48}$Ca+$^{249}$Bk quasifission fragments. https://doi.org/10.1103/physrevc.100.024610

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