The orientation distribution of tunneling-related quantities

J. Phys. G: Nucl. Part. Phys.

Abdulghany

Hussein

2021

We investigate the change of the neutron-skin thickness from parent to daughter nuclei involved in the cluster decay process. The neutron-skin thickness is obtained using self-consistent Hartree–Fock–Bogolyubov calculations based on Skyrme-SLy4 effective nucleon–nucleon interaction. The experimental data of the cluster decay modes observed to date indicate that the shell effect then the released energy play the predominate role of determining the spontaneous cluster decay modes. The effect of the change in the neutron-skin thickness from parent to daughter nuclei comes next to them. The cluster decay preferably proceeds to yield the least possible increase in the neutron-skin thickness of the daughter nucleus (δ n). δ n decreases when the isospin-asymmetry of the emitted cluster increases. The relative stability of the radioactive nucleus and its corresponding partial half-life increase for the cluster decays leading to a significant increase in the neutron-skin thickness.

Section: Resultsmentioning

confidence: 99%

Change in neutron skin thickness after cluster-decay

J. Phys. G: Nucl. Part. Phys.

Abdulghany

Hussein

2021

“…The dimensions of matrix elements were reduced using surface delta interaction in truncated model space [16]. The existence of α-core structure has been confirmed in the framework of both the shell model and the cluster model within bases of large dimensions, and using Gaussian-bases and large number of configurations [19,20]. Moreover, the α clustering has been described in numerous clusterformation states [21].…”

Section: Introductionmentioning

confidence: 88%

“…( 8) is calculated at a sufficiently large distance [17], where the amplitude becomes constant. The assault frequency at which the formed cluster hits the Coulomb barrier can be obtained using the Wentzel-Kramers-Brillouin (WKB) approximation as the inverse of the time taken by the cluster to make one oscillation within the internal pocket of the interaction potential, between and [19,20],…”

Section: Theoretical Formalismmentioning

confidence: 99%

Formation region of emitted α and heavier particles inside radioactive nuclei

Abdel-Hady

2020

Chinese Phys. C

Self Cite

We investigate the formation distance (R 0) from the center of the radioactive parent nucleus at which the emitted cluster is most probably formed. The calculations are performed microscopically starting with the solution to the time-independent Schrödinger wave equation for the cluster-core system, using nuclear potentials based on the Skyrme-SLy4 nucleon-nucleon interactions and folding Coulomb potential, to determine the incident and transmitted wave functions of the system. Our results show that the emitted cluster is mostly formed in the pre-surface region of the nucleus, under the effect of Pauli blocking from the saturated core density. The deeper α-formation distance inside the nucleus allows less preformation probability and indicates a more stable nucleus for a longer half-life. Furthermore, the α-particle tends to be formed at a slightly deeper region inside the nuclei, with larger isospin asymmetry, and in the closed shell nuclei. Regarding the heavy clusters, we observed that the formation distance of the emitted clusters heavier than α-particle increased via increasing the isospin asymmetry of the formed cluster rather than by increasing its mass number. The partial half-life of a certain cluster-decay mode increased with increase of either the mass number or the isospin asymmetry of the emitted cluster.

“…R i=1,2,3 (θ) at which V T (r, θ) = Q α are three orientation-dependent turning points along the radial path. R 3 , which is de ned in the far tail region of the potential is rather orientation independent [30,31].…”

Section: Theoretical Frameworkmentioning

confidence: 99%

“…The orientation-averaged decay width is numerically determined in terms of the decay widths at different orientation angles [30,42],…”

Section: Theoretical Frameworkmentioning

confidence: 99%

Hindrance factors of unfavored α decay transitions to duplicated daughter states of the same spin and parity

J. Phys. G: Nucl. Part. Phys.

Hashem

2020

We investigate the hindrance of the unfavored α-decay modes to the different daughter states, which have different spin than that of the parent nucleus but of the same parity. The duplicated daughter nucleus states of identical spin-parity (Jπ) are ascendingly ordered according to the sequence of their excitation energy. We found that the hindrance of the unfavored decay modes increases with increasing the difference in spin (ΔJ) between the parent and daughter states. This hindrance slightly increases when the daughter state has less spin than the parent. The preformation probability (Sα) decreases with ΔJ and the decay slows down. Furthermore, the increase of the order (n) of the state to which the decay takes place brings the decay intensity drop significantly and decrease. Consequently, the partial half-life strongly increases with n. The hindrance factor averagely drops from few tenths, for an unfavored decay mode to first appearing state of a certain Jπ, to about 10−9 for the decay mode to the identical excited state that appear for the sixth time. The associated half-lives accordingly increase with the reciprocal ratios. The value of the corresponding preformation probability drops about 3 orders of magnitude. Simple formulas are given to describe the hindrance of both the unfavored decay intensity and Sα as functions of ΔJ and n.