Nuclear Theory·nucl-th

Friday·August 23, 2019

9 papers—4 primary·5 cross-listed

01
Skyrme Functional with Tensor Terms from ab initio Calculations: Results for the Spin-Orbit Splittings
Shihang Shen · Gianluca Colò · Xavier Roca-Maza
A new Skyrme functional including tensor terms is presented. The tensor terms have been determined by fitting the results of relativistic Brueckner-Hartree-Fock (RBHF) studies on neutron-proton drops. Unlike all previous studies, where the tensor terms were usually determined by fitting to experimental data of single-particle levels, the pseudodata calculated by RBHF does not contain beyond mean-field effect such as the particle-vibration coupling and, therefore, can provide information on the tensor term without ambiguities. The obtained new functional, named SAMi-T, can describe well ground-state properties such as binding energies, radii, spin-orbit splittings and, at the same time, the excited state properties such as those of the Giant Monopole Resonance (GMR), Giant Dipole Resonance (GDR), Gamow-Teller Resonance (GTR), and Spin-Dipole Resonance (SDR).
nucl-thActa Phys.Polon.Supp.(2019)·0 citations
02
New magicity $N = 32$ and $34$ triggered by strong couplings between Dirac inversion partners
Jia Liu · Yi Fei Niu · Wen Hui Long
Inspired by recent experiments, the successive new magicity $N = 32$ and $34$ in Ca isotopes are studied within the relativistic density functional theory. It is illustrated that the strong couplings between the $s_{1/2}$ and neutron ( $ν$ ) $ν 2 p_{1/2}$ orbits, here referred as "Dirac inversion partners" (DIPs), play a key role in opening both subshells $N = 32$ and $34$ . Such strong couplings originate from the inversion similarity between the DIPs, that the upper component of the Dirac spinor of one partner shares the same orbital angular momentum as the lower component of the other, and vice versa. Following the revealed mechanism, it is predicted that the magicity $N = 32$ is reserved until $^{48}$ S, but vanishes in $^{46}$ Si.
nucl-thPLB(2020)·33 citations
03
From response functions to cross sections in neutrino scattering off the deuteron and trinucleons
J. Golak · R. Skibinski · K. Topolnicki · H. Witala · A. Grassi · H. Kamada · L. E. Marcucci
Response functions, differential cross sections and total cross sections for several (anti)neutrino induced reactions on 2H, 3He and 3H are calculated in momentum space for (anti)neutrino energies up to 160 MeV, using the AV18 nucleon-nucleon potential and a single-nucleon weak current operator. This work is a continuation of our investigations presented in J. Golak et al. [Phys. Rev. C 98, 015501 (2018)].
nucl-thPRC(2019)·7 citations
04
First-forbidden transitions in the reactor anomaly
Leendert Hayen🇧🇪 · Joel Kostensalo🇫🇮 · Nathal Severijns🇧🇪 · Jouni Suhonen🇫🇮
We describe here microscopic calculations performed on the dominant forbidden transitions in reactor antineutrino spectra above 4 MeV using the nuclear shell model. By taking into account Coulomb corrections in the most complete way, we calculate the shape factor with the highest fidelity and show strong deviations from allowed approximations and previously published results. Despite small differences in the ab initio electron cumulative spectra, large differences on the order of several percents are found in the antineutrino spectra. Based on the behaviour of the numerically calculated shape factors we propose a parametrization of forbidden spectra. Using Monte Carlo techniques we derive an estimated spectral correction and uncertainty due to forbidden transitions. We establish the dominance and importance of forbidden transitions in both the reactor anomaly and spectral shoulder analysis. Based on these results, we conclude that a correct treatment of forbidden transitions is indispensable in both the normalization anomaly and spectral shoulder.
nucl-thhep-exnucl-exPRC(2019)·102 citations

Affiliations

first authorsco-authorsvia INSPIRE

Skyrme Functional with Tensor Terms from ab initio Calculations: Results for the Spin-Orbit Splittings

New magicity N=32 and 34 triggered by strong couplings between Dirac inversion partners

From response functions to cross sections in neutrino scattering off the deuteron and trinucleons

First-forbidden transitions in the reactor anomaly

Affiliations

New magicity $N = 32$ and $34$ triggered by strong couplings between Dirac inversion partners