Nuclear Theory·nucl-th

Tuesday·January 14, 2025

12 papers—2 primary·10 cross-listed

01
[Submitted on 13 Jan 2025]
Energy partition between splitting fission fragments
Haoyu Shang · Yu Qiang · Junchen Pei
From the microscopic view, the energy partition between two fission fragments are associated with the splitting of wave functions of an entangled fissioning system, in contrast to most fission models using an explicit statistical partition of excitation energies by invoking level densities of fragments. The dynamical fission evolution is described within the time-dependent Hartree-Fock+BCS framework. Excitation energies of isotopic fission fragments are obtained with the particle-number projection method after the dynamical splitting of $^{238}$ U. The resulting excitation energies of light and heavy fragments illustrate the appearance of sawtooth structures. We find that the paring strengths have significant influences on the partition of excitation energies. Furthermore, excitation energies of isotopic fragments increase with increasing neutron numbers, suppressing the production of neutron-rich beams in rare-isotope beam facilities.
Comments:
6 Pages, 3 figures, submitted
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2501.07118 [pdf]
Nucl.Sci.Tech.(2025)·4 citations
02
[Submitted on 13 Jan 2025]
Novel way of evaluating $g_{A}$ quenching in $β^{+}$ /EC decays : Introducing the Branching-Ratio Method (BRM)
Aagrah Agnihotri · Jouni Suhonen
The novel Branching-Ratio Method (BRM) for the determination of effective value $g_{A}^{eff}$ of the weak axial coupling $g_{A}$ for forbidden non-unique (FNU) $β^{+}$ /electron-capture(EC) decays is introduced. The method offers new possibilities for testing the fitness of nuclear Hamiltonians in modeling the physics of complex $β^{+}$ /EC decays. The constraint of simultaneously reproducing the branching to $β^{+}$ and EC transitions offers an additional constraint in tackling the problem of $g_{A}^{eff}$ determination. In the BRM the ambiguity in the choice of the values of $g_{A}^{eff}$ and s-NME (small relativistic vector nuclear matrix element) is lifted when constraints of the branching ratios of $β^{+}$ and EC decays are applied. As an example, in the present work we apply BRM to the case of second FNU $β^{+}$ /EC decay of $^{59}$ Ni. This decay is treated with three different nuclear shell-model (NSM) Hamiltonians demonstrating the effects of different nuclear-structure aspects in application of the BRM.
Comments:
7 pages, 5 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2501.07370 [pdf]
PLB(2025)·0 citations

Affiliations

first authorsco-authorsvia INSPIRE

Energy partition between splitting fission fragments

Novel way of evaluating gA​ quenching in β+/EC decays : Introducing the Branching-Ratio Method (BRM)

Affiliations

Novel way of evaluating $g_{A}$ quenching in $β^{+}$ /EC decays : Introducing the Branching-Ratio Method (BRM)