We study the structure of the neutron rich $^{44}$S isotope with modern configuration mixing methods based on the Gogny interaction including beyond-mean-field effects. Restoration of particle number and rotational symmetries are taken into account as well as shape mixing in the whole triaxial $(β_{2},γ)$ plane. We obtain a qualitative agreement between the calculated spectrum and the experimental data reported recently. Very extended collective wave functions in the $(β_2,γ)$ plane are found for the lowest states, corresponding to very flat potentials, indicating strong configuration mixing and supporting the weakening of the N=28 magic number.
In this paper, we used a transitional Hamiltonian which has $U(5)\leftrightarrow(6)$ transition to improve theoretical predictions for energy spectra and quadrupole transition rates of $^{112}$Cd nucleus. To this aim, the transitional Hamiltonian in the affine $SU(1,1)$ algebra has been extended by adding the $O(6)$-Casimir operator and mixing Hamiltonian to increase exactness in the description of 4$^+_2$ and 2$^+_3$ intruder levels of this nucleus. We also considered the wave functions of both regular and intruder states, as a combination in the $N$ and $N+2$ boson spaces. The results confir…
We develop for the first time a microscopic global nucleon-nucleus optical potential with quantified uncertainties suitable for analyzing nuclear reaction experiments at next-generation rare-isotope beam facilities. Within the improved local density approximation and without any adjustable parameters, we begin by computing proton-nucleus and neutron-nucleus optical potentials from a set of five nuclear forces from chiral effective field theory for 1800 target nuclei in the mass range 12 $\leq$ A $\leq$ 242 for energies between 0 MeV $<$ E $\lesssim$ 150 MeV. We then parameterize a global optic…
Background: The isospin mixing is an interesting feature of atomic nuclei. It plays a crucial role in astrophysical nuclear reactions. However, it is not straightforward for variational nuclear structure models to describe it. Purpose: We propose a tractable method to describe the isospin mixing within a framework of the generator coordinate method and demonstrate its usability. Method: We generate the basis wave functions by applying the Fermi transition operator to the wave functions of isobars. The superposition of these basis wave functions and variationally obtained wave functions quantit…
Scrupulous theoretical study of 8Be nucleus states, both clustered and non-clustered, is performed over a wide range of the excitation energies. The quantities which characterize the degree of the alpha-clustering of these states: spectroscopic factors, cluster form factors as well as the alpha-decay widths are computed in the framework of an accurate ab initio approach developed. Other basic properties of 8Be spectrum: the binding and excitation energies, mean values of the isospin are calculated simultaneously. In the majority of instances the results of the computations turn out to be in a …
Lying at the lower edge of the `island of inversion', neutron-rich Fluorine isotopes ($^{29-31}$F) provide a curious case to study the configuration mixing in this part of the nuclear landscape. Recent studies have suggested that a prospective two-neutron halo in the dripline nucleus $^{31}$F could be linked to the occupancy of the $pf$ intruder configurations. Focusing on configuration mixing, matter radii and neutron-neutron ($nn$) correlations in the ground-state of $^{31}$F, we explore various scenarios to analyze its possible halo nature as well as the low-lying electric dipole ($E$1) res…
Description of nuclear systems with a self-consistent configuration-mixing approach. I: Theory, algorithm, and application to the $^{12}$C test nucleus
虽然自洽多组态方法已经被用于描述原子和分子多体系统几十年，只有少数的试验已经在原子核结构的背景下进行。这项工作的目的是发展这样一种方法来描述在一个统一的方式在核中的各种类型的相关性，在一个自洽的方式，其中的平均场的相关性得到改善。我们的目标是调和通常分开壳模型和自洽平均场方法。这种方法被称为“变分多粒子-多孔组态混合方法”。它是基于双变分原理，产生一组两个耦合方程，确定在同一时间的多体波函数和单粒子状态的展开系数。的形式主义推导和讨论的一般情况下，从一个三体哈密顿。链接到现有的多体技术，如格林函数的形式主义建立。第一个应用程序是使用两体D1 S Gogny有效力完成的。在$^{12}$ C核上测试了数值计算过程，以研究该算法在不同情况下的收敛特性。基态属性以及单粒子数量进行了分析，并检查的第一个$2^+$状态的描述。这项研究允许验证我们的数值算法，并导致令人鼓舞的结果。为了进一步测试该方法，我们将在本系列的第二篇文章中实现，通过应用新开发的数值方法，在相同的Gogny力下，系统地描述更多的原子核和可观测量。正如在本工作中提出的，应用程序的变分多粒子多孔配置混合方法，但最终需要使用一个扩展的和更多的约束Gogny力。
We present the results of semi-inclusive neutrino-nucleus cross sections within the plane wave impulse approximation (PWIA) for three nuclear models: relativistic Fermi gas (RFG), independent-particle shell model (IPSM) and natural orbital shell model (NO) in comparison with the available CC0$π$ measurements from the T2K, MINER$ν$A and MicroBooNE collaborations where a muon and at least one proton are detected in the final state. Results are presented as a function of the momenta and angles of the final particles, as well as in terms of the imbalances between proton and muon kinematics. The an…
The description of hadron production in relativistic heavy-ion collisions in the statistical hadronization model is very good, over a broad range of collision energy. We outline this both for the light (u, d, s) and heavy (charm) quarks and discuss the connection it brings to the phase diagram of QCD.
In this work, we have performed large-scale shell-model calculations for the first-forbidden $β^{-}$ decay of $^{207}$Hg into the one-proton-hole nucleus $^{207}$Tl corresponding to the recently available experimental data from ISOLDE-CERN [T. A. Berry et al., Phys. Rev. C 101, 054311 (2020)]. We have used the one-particle one-hole ($1p$-$1h$) truncation for both protons and neutrons simultaneously across the doubly-shell closure at $^{208}$Pb in the final states of $^{207}$Tl. In our calculations, we have also considered the effect of mesonic enhancement $ε_{\mathrm{mec}}=2.01\pm 0.05$ in the…
We present a new model for the description of heavy-flavor hadronization in relativistic heavy-ion collisions. We explore its effect on the charmed hadron yields and kinematic distributions once the latter is applied at the end of transport calculations used to simulate the propagation of heavy quarks in the deconfined fireball produced in the collision. The model is based on the formation of color-singlet clusters through the recombination of charm quarks with light antiquarks or diquarks from the same fluid cell. This local mechanism of color neutralization leads to a strong space-momentum c…
