Production of very neutron-rich nuclei with a 76Ge beam
O. B. Tarasov, M. Portillo, A. M. Amthor, T. Baumann, D. Bazin, A. Gade, T. N. Ginter, M. Hausmann, N. Inabe, T. Kubo, D. J. Morrissey, A. Nettleton, J. Pereira… 展开作者
O. B. Tarasov, M. Portillo, A. M. Amthor, T. Baumann, D. Bazin, A. Gade, T. N. Ginter, M. Hausmann, N. Inabe, T. Kubo, D. J. Morrissey, A. Nettleton, J. Pereira, B. M. Sherrill, A. Stolz, M. Thoennessen
Production cross sections for neutron-rich nuclei from the fragmentation of a 76Ge beam at 132 MeV/u were measured. The longitudinal momentum distributions of 34 neutron-rich isotopes of elements 13 <= Z <= 27 were scanned using a novel experimental approach of varying the target thickness. Production cross sections with beryllium and tungsten targets were determined for a large number of nuclei including 15 isotopes first observed in this work. These are the most neutron-rich nuclides of the elements 17 <= Z <= 25 (50Cl, 53Ar, 55,56K, 57,58Ca, 59,60,61Sc, 62,63Ti, 65,66V, 68Cr,70Mn). A one-body Qg systematics is used to describe the production cross sections based on thermal evaporation from excited prefragments. Some of the fragments near 58Ca show anomalously large production cross sections.
Some critical comments and remarks on the article "Comparison of two experiments on radiative neutron decay" by R.U.Khafizov et al., published in Physics of Atomic Nuclei.
Clustering is a relatively widespread phenomena which takes on many guises across the nuclear landscape. Selected topics concerning the study of halo systems and clustering in light, neutron-rich nuclei are discussed here through illustrative examples taken from the Be isotopic chain.
As proposed recently by Fornal and Grinstein, neutrons can undergo a dark matter decay mode which was not observed before. Such a decay could explain the existing discrepancy between two different methods of neutron lifetime measurements. If such neutron decay is possible, then it should occur also is nuclei with sufficiently low neutron binding energy. We examine a few nuclear candidates for the dark neutron decay and we consider possibilities of their experimental identification. In more detail we discuss the case of $^{11}$Be which appears as the most promising nucleus for the observation o…
Studies attempting to probe the spatial configuration of the valence neutrons in two-neutron halo nuclei using the technique of intensity interferometry are described. Following a brief review of the method and its application to earlier measurements of the breakup of 6He, 11Li and 14Be, the results of the analysis of a high statistics data set for 6He are presented. The limitations of the technique, including the assumption of incoherent emission in the breakup and the sensitivity to the continuum states populated in the dissociation rather than the ground state, are discussed.
The three-body description of two-neutron halo nuclei relies on the two-body interactions between the constituents. In order to provide constraints on calculations devoted to $^{14}$Be and $^{17}$B, neutron unbound states of $^{13}$Be and $^{16}$B have been investigated by one-proton knockout. The experimental techniques and results are discussed here.
Selected topics on halo and molecular states in light, neutron-rich nuclei are discussed. In particular, work on $xα$:X$n$ structures is briefly reviewed. The use of proton radiative capture as a probe of clustering is also presented through the example provided by the $^6$He(p,$γ$) reaction.
The JYFLTRAP mass spectrometer was used to measure the masses of neutron-rich nuclei in the region between N = 28 to N = 82 with uncertainties better than 10 keV. The impacts on nuclear structure and the r-process paths are reviewed.
Paring correlations in weakly bound halo nuclei $^{6}$He and $^{11}$Li are studied by using a three-body model with a density-dependent contact interaction. We investigate the spatial structure of two-neutron wave function in a Borromean nucleus $^{11}$Li.The behavior of the neutron pair at different densities is simulated by calculating the two-neutron wave function at several distances between the core nucleus $^9$Li and the center of mass of the two neutrons. With this representation, a strong concentration of the neutron pair on the nuclear surface is quantitatively established for neutron…
The fragmentation of neutron-rich 132Sn nuclei produced in the fission of 238U projectiles at 950 MeV/u has been investigated at the FRagment Separator (FRS) at GSI. This work represents the first investigation of fragmentation of medium-mass radioactive projectiles with a large neutron excess. The measured production cross sections of the residual nuclei are relevant for the possible use of a two-stage reaction scheme (fission+fragmentation) for the production of extremely neutron-rich medium-mass nuclei in future rare-ion-beam facilities. Moreover, the new data will provide a better understa…
We propose to search for neutron halo isomers populated via $γ$-capture in stable nuclei with mass numbers of about A=140-180 or A=40-60, where the $4s_{1/2}$ or $3s_{1/2}$ neutron shell model state reaches zero binding energy. These halo nuclei can be produced for the first time with new $γ$-beams of high intensity and small band width ($\le$ 0.1%) achievable via Compton back-scattering off brilliant electron beams thus offering a promising perspective to selectively populate these isomers with small separation energies of 1 eV to a few keV. Similar to single-neutron halo states for very ligh…
A systematic study of the $β$-decay of neutron-deficient nuclei has been carried out and has provided spectroscopic information of importance for both nuclear structure and nuclear astrophysics. Following an overview of the most relevant achievements, we focus on the latest results on the $β$ decay of $^{60}$Ge and $^{62}$Ge. We also summarise our results on the mass excesses in comparison with systematics and a recent measurement. Finally, we present updated half-life trends for $T_z=$ -1/2, -1 and -2 neutron-deficient nuclides.
The model of three-body Borromean halo nuclei breakup was described by using standard phase space distributions and the Monte Carlo simulation method was established to resolve the detection problem of two neutrons produced from breakup reaction on the neutron wall detector. For $^{6}$He case, overall resolution $σ_{E_{k}}$ for the Gaussian part of the detector response and the detection efficiency including solid angle acceptance with regard to the excitation energy $E_{k}$ are obtained by the simulation of two neutrons from $^{6}$He breakup into the neutron wall. The effects of the algorithm…
The di-neutron correlation is a spatial correlation with which two valence neutrons are located at a similar position inside a nucleus. We discuss possible experimental probes for the di-neutron correlation. This includes the Coulomb breakup and the pair transfer reactions of neutron-rich nuclei, and the direct two-neutron decays of nuclei beyond the neutron drip-line.
We discuss a decay of unbound nuclei beyond the neutron drip-line using a three-body model with a core nucleus and two valence neutrons. We particularly discuss the role of dineutron correlation between the valence neutrons in the two-neutron emission from the ground state of $^{26}$O and $^{10}$He nuclei. Our calculations clearly indicate that the emission of the two neutrons in the back-to-back direction is enhanced due to the dineutron correlation.
A new method is proposed to deduce the neutron radii of neutron-rich nuclei. This method requires measuring the reaction cross sections of both the neutron-rich nucleus and its stable isotope at the same energy on a proton target. Using this method and the available experimental data of $^{12,22}$C + $p$ and $^{9,14}$Be + $p$ at 40$A$ MeV, the neutron radii of $^{22}$C and $^{14}$Be have been deduced for the first time.
We evaluate the reflectivity of neutron mirrors composed of certain heavy nuclei which possess strong neutron-nucleus resonances in the eV energy range. We show that the reflectivity of such a mirror for some nuclei can in principle be high enough near energies corresponding to compound neutron-nucleus resonances to be of interest for certain scientific applications in non-destructive evaluation of subsurface material composition and in the theory of neutron optics beyond the kinematic limit.
Several neutron capture cross sections of light neutron-rich nuclei were measured in the astrophysically relevant energy region of 5 to 200 keV. The experimental data are compared to calculations using the direct capture model. The results are used for the calculation of neutron capture cross sections of unstable isotopes. Furthermore, neutron sources with energies below E_n \approx 10 keV are discussed.
Multi-neutron systems are crucial to understanding the physics of neutron-rich nuclei and neutron stars. Neutron drops, neutrons confined in an external field, are investigated systematically in both non-relativistic and relativistic density functional theories and with ab initio calculations. We demonstrate a strong linear correlation, which is universal in the realm of mean-field models, between the rms radii of neutron drops and the neutron skin thickness of Pb-208 and Ca-48; i.e., the difference between the neutron and proton rms radii of a nucleus. Due to its high quality, this correlatio…
Interference effect of neutron capture cross section between the compound and direct processes is investigated. The compound process is calculated by resonance parameters and the direct process by the potential mode. The interference effect is tested for neutron-rich $^{82}$Ge and $^{134}$Sn nuclei relevant to $r$-process and light nucleus $^{13}$C which is neutron poison in the $s$-process and produces long-lived radioactive nucleus $^{14}$C ($T_{1/2}=5700$ y). The interference effects in those nuclei are significant around resonances, and low energy region if $s$-wave neutron direct capture …
Based on the relativistic calculations of the nuclear masses in the transfermium region from No $(Z=102)$ to Ds $(Z=110)$ by the deformed relativistic Hartree-Bogoliubov theory in continuum, the possible existence of the bound nuclei beyond the neutron drip lines is studied. The two-neutron and multi-neutron emission bound nuclei beyond the primary neutron drip line of $N=258$ are predicted in $Z=106,108$ and $110$ isotopes. Detailed microscopic mechanism investigation reveals that nuclear deformation plays a vital role in the existence of the bound nuclei beyond the drip line. Furthermore, no…
Paring correlations in weakly bound nuclei on the edge of neutron drip line is studied by using a three-body model. A density-dependent contact interaction is employed to calculate the ground state of halo nuclei $^{6}$He and $^{11}$Li, as well as a skin nucleus $^{24}$O. Dipole excitations in these nuclei are also studied within the same model. We point out that the di-neutron type correlation plays a dominant role in the halo nuclei $^{6}$He and $^{11}$Li having the coupled spin of the two neutrons $S$=0, while the correlation similar to the BCS type is important in $^{24}$O. Contributions o…
We review the impact of nuclear forces on matter at neutron-rich extremes. Recent results have shown that neutron-rich nuclei become increasingly sensitive to three-nucleon forces, which are at the forefront of theoretical developments based on effective field theories of quantum chromodynamics. This includes the formation of shell structure, the spectroscopy of exotic nuclei, and the location of the neutron dripline. Nuclear forces also constrain the properties of neutron-rich matter, including the neutron skin, the symmetry energy, and the structure of neutron stars. We first review our unde…
Using a fully quantum mechanical post-form finite-range distorted-wave Born approximation theory of Coulomb breakup, I study the parallel momentum distribution of the core in the Coulomb breakup of suggested excited-state one-neutron halo nuclei considered in their different bound excited states. Narrow momentum distributions obtained in the present calculations for some cases indicate the possibilities of the excited-state halo structure in the nuclei under consideration and therefore favor the previous predictions.
Neutron-rich nuclei and neutron skins from chiral low-resolution interactions
Université Paris-Saclay（巴黎萨克雷大学）；CNRS/IN2P3, IJCLab（法国国家科学研究中心/欧洲核子研究组织，IJCLab）；Helmholtz Forschungsakademie Hessen für FAIR (HFHF)（黑森州亥姆霍兹FAIR研究院）；GSI Helmholtzzentrum für Schwerionenforschung GmbH（德国重离子研究中心）；ExtreMe Matter Institute EMMI（极端物质研究所）；Max-Planck-Institut für Kernphysik（马克斯·普朗克核物理研究所）；Technische Universität Darmstadt（达姆施塔特工业大学）
The formation of $α$-particle clusters on the surface of heavy nuclei is described in a generalized relativistic mean-field model with explicit cluster degrees of freedom. The effects on the size of the neutron skin of Sn nuclei and ${}^{208}$Pb are investigated as a function of the mass number and the isospin-dependent part of the effective interaction, respectively. The correlation of the neutron skin thickness with the difference of the neutron and proton numbers and with the slope of the nuclear symmetry energy is modified as compared to the mean-field calculation without alpha-cluster cor…
Based on time-dependent Hartree-Fock theory, a new inverse quasifission mechanism is proposed to produce neutron-rich transfermium nuclei, in collision of prolate deformed actinides. Calculations show that collision of the tip of one nucleus with the side of the other results in a nucleon flux toward the latter. The role of nucleon evaporation and impact parameter, as well as the collision time are discussed.
Recent experiments have demonstrated that the rotational-alignment for the $N=Z$ nuclei in the mass-80 region is considerably delayed as compared to the neighboring $N \ne Z$ nuclei. We investigate whether this observation can be understood by a known component of nuclear residual interactions. It is shown that the quadrupole-pairing interaction, which explains many of the delays known in rare-earth nuclei, does not produce the substantial delay observed for these $N=Z$ nuclei. However, the residual neutron-proton interaction which is conjectured to be relevant for $N=Z$ nuclei is shown to be …
About half of the heavy elements in the Solar System were created by rapid neutron capture, or r-process, nucleosynthesis. In the r-process, heavy elements are built up via a sequence of neutron captures and beta decays in which an intense neutron flux pushes material out towards the neutron drip line. The nuclear network simulations used to test potential astrophysical scenarios for the r-process therefore require nuclear physics data (masses, beta decay lifetimes, neutron capture rates, fission probabilities) for thousands of nuclei far from stability. Only a small fraction of this data has …
From the experimental data on odd-even staggering of masses, we have shown that variation of pairing as a function of neutron number plays an important role in many distinctive features like occurrence of new shell closures, shell erosion, anomalous reduction of the energy of the first 2+ state and slower increase in the B(E2, 2_{+}^{1} \rightarrow 0_{+}^{1}) in the neutron-rich even-even nuclei in different mass regions. New predictions have been made in a model independent way. Results of theoretical calculations support the phenomenological findings.
A deformed relativistic Hartree-Bogoliubov theory in continuum has been developed for the study of neutron halos in deformed nuclei and the halo phenomenon in deformed weakly bound nuclei is investigated. Magnesium and neon isotopes are studied and some results are presented for the deformed neutron-rich and weakly bound nuclei 44Mg and 36Ne. The core of the former nucleus is prolate, but the halo has a slightly oblate shape. This indicates a decoupling of the halo orbitals from the deformation of the core. The generic conditions for the existence of halos in deformed nuclei and for the occurr…
Within the complex-energy configuration interaction framework, we study correlations of valence neutrons to explain the behavior of charge radii in the neutron halo nuclei $^{6,8}$He. We find that the experimentally observed decrease of the charge radius between $^6$He and $^8$He is caused by a subtle interplay between three effects: dineutron correlations, a spin-orbit contribution to the charge radius, and a core swelling effect. We demonstrate that two-neutron angular correlations in the $2^+_1$ resonance of $^6$He differ markedly from the ground-state correlations in $^{6,8}$He.
Background: Measurements of neutron radii provide important constraints on the isovector sector of nuclear density functionals and offer vital guidance in areas as diverse as atomic parity violation, heavy-ion collisions, and neutron-star structure. Purpose: To assess the impact of spin-orbit currents on the electromagnetic- and weak-charge radii of a variety of nuclei. Special emphasis is placed on the experimentally accessible electroweak skin, defined as the difference between weak-charge and electromagnetic-charge radii. Methods: Two accurately calibrated relativistic mean field models are…
We present quantum Monte Carlo calculations of light nuclei, neutron-$α$ scattering, and neutron matter using local two- and three-nucleon ($3N$) interactions derived from chiral effective field theory up to next-to-next-to-leading order (N$^2$LO). The two undetermined $3N$ low-energy couplings are fit to the $^4$He binding energy and, for the first time, to the spin-orbit splitting in the neutron-$α$ $P$-wave phase shifts. Furthermore, we investigate different choices of local $3N$-operator structures and find that chiral interactions at N$^2$LO are able to simultaneously reproduce the proper…
Alternative methods to calculate neutron capture cross sections on radioactive nuclei are reported using the theory of Inclusive Non-Elastic Breakup (INEB) developed by Hussein and McVoy [1]. The statistical coupled-channels theory proposed in Ref. [2] is further extended in the realm of random matrices. The case of reactions with the projectile and the target being two-cluster nuclei is also analyzed and applications are made for scattering from a deuteron target [3]. An extension of the theory to a three-cluster projectile incident on a two-cluster target is also discussed. The theoretical d…
Starting from the microscopic low-momentum nucleon-nucleon interaction V{low k}, we present the first systematic shell model study of magnetic moments and magnetic dipole transition strengths of the basic low-energy one-quadrupole phonon excitations in nearly-spherical nuclei. Studying in particular the even-even N=52 isotones from 92Zr to 100Cd, we find the predicted evolution of the predominantly proton-neutron non-symmetric state reveals a restoration of collective proton-neutron mixed-symmetry structure near mid-shell. This provides the first explanation for the existence of pronounced col…
Insights into the equation of state of neutron rich matter obtained from the neutron skin thickness of 208Pb are in sharp conflict with earlier measurements of the electric dipole polarizability. We use a set of accurately calibrated energy density functionals to highlight the tension and to articulate how plans for a highly-intense Gamma Factory may alleviate the tension.
The dependence of fusion dynamics on neutron excess for light nuclei is extracted. This is accomplished by comparing the average fusion cross-section at energies just above the fusion barrier for $^{12-15}$C + $^{12}$C with measurements of the interaction cross-section from high evergy collisions. The experimental results indicate that the fusion cross-section associated with dynamics increases with increasing neutron excess. Calculations with a time-dependent Hartree-Fock model fail to describe the observed trend.
Neutron-skins in coordinate space and proton-skins in momentum space are predicted to coexist in heavy nuclei and their correlation is governed by Liouville's theorem and Heisenberg's uncertainty principle. An analysis of their correlation within a further extended Thomas-Fermi (ETF$^+$) approximation incorporating effects of nucleon short-range correlations reveals generally that protons move faster than neutrons in neutron-skins of heavy nuclei.
We present model results for the two-halo-neutron correlation functions, $C_{nn}$, for the dissociation process of light exotic nuclei modelled as two neutrons and a core. A minimum is predicted for $C_{nn}$ as a function of the relative momentum of the two neutrons, $p_{nn}$, due to the coherence of the neutrons in the halo and final state interaction. Studying the systems $^{14}$Be, $^{11}$Li and $^{6}$He within this model, we show that the numerical asymptotic limit, $C_{nn}\to 1$, occurs only for $p_{nn}\gtrsim$ 400 MeV$/c$, while such limit is reached for much lower values of $p_{nn}$ in …
The ratio of pre-equilibrium neutrons to protons from collisions of neutron-rich nuclei is studied as a function of their kinetic energies. This ratio is found to be sensitive to the density dependence of the nuclear symmetry energy, but is independent of the compressibility of symmetric nuclear matter and the in-medium nucleon-nucleon cross sections. The experimental measurement of this ratio thus provides a novel means for determining the nuclear equation of state of asymmetric nuclear matter.
A recent Letter attempted to reconcile the disagreement between neutron resonance data and random matrix theory (RMT). To this end, a new formula was derived for transforming measured (Γ_{λn}) to reduced (Γ_{λn}^0) neutron widths for s-wave resonances (λ=1,2,...) in nuclides near peaks of the s-wave neutron strength function. In this Comment, we show that such a rescaling would not, in general, be expected to reconcile the type of disagreement observed, and demonstrate that indeed it does not for the specific cases in question. Hence, the disagreements between RMT and these data remain.
It has been recently suggested that differences in the charge radii of mirror nuclei are proportional to the neutron-skin thickness of neutron-rich nuclei and to the slope of the symmetry energy $L$ [B.A. Brown Phys. Rev. Lett. 119, 122502 (2017)]. The determination of the neutron skin has important implications for nuclear physics and astrophysics. Although the use of electroweak probes provides a largely model-independent determination of the neutron skin, the experimental challenges are enormous. Thus, the possibility that differences in the charge radii of mirror nuclei may be used as a su…
A proposal approved by the Jefferson Lab (JLab) PAC to study the proton-to-neutron momentum distribution ratio in A=3 nuclei via (e,e'p) scattering off 3He and 3H mirror nuclei. The experiment will measure the 3H(e,e'p) and 3He(e,e'p) cross-sections and cross-section ratios at Q2 = 2 and xB>1 kinematics, over a missing momentum range of 0 - 450 MeV/c. The experiment was approved in 2014 at part of the JLab Hall-A Tritium run period for a total run time of 12 days.
The synthesis of hyper-heavy elements is investigated under conditions simulating neutron star environment. The Constrained Molecular Dynamics (CoMD) approach is used to simulate low energy collisions of extremely n-rich nuclei. A new type of the fusion barrier due to a "neutron wind" is observed when the effect of neutron star environment (screening of Coulomb interaction) is introduced implicitly. When introducing also a background of surrounding nuclei, the nuclear fusion becomes possible down to temperatures of 10$^{8}$ K and synthesis of extremely heavy and n-rich nuclei appears feasible.…
Background: Multi-nucleon transfer reactions have recently attracted attention as a possible path to the synthesis of new neutron-rich heavy nuclei. Purpose: We study transfer reactions involving massive nuclei with the intention of understanding if the semi-classical model GRAZING coupled to an evaporation and fission competition model can satisfactory reproduce experimental data on transfer reactions in which fission plays a role. Methods: We have taken the computer code GRAZING and have added fission competition to it (GRAZING-F) using our current understanding of $Γ_n/Γ_f$, fission barrier…
Ground-state moments of inertia (MoI) are investigated for about 1700 even-even nuclei from the proton drip line to the neutron drip line up to $Z=120$ and $N=184$. The cranked Skyrme-Hartree-Fock-Bogoliubov equation is solved in the coordinate space. This model describes well the available experimental data of more than 300 nuclides possessing an appreciable deformation. I find that the MoI greatly increase near the drip line whereas the deformation is not as strong as estimated by the empirical relation. Systematic measurements of the excitation energy and the transition probability to the f…
It is shown that the hole in the centre of $ ^{3}H $, $ ^{3}He $ and $ ^{4}He $, the neutron halos in nuclei, the $ α- $ and other clustering effects in nuclei and the nuclear molecules all basically arise due to the same underlying effect. We shall show that all these ground state properties of nuclei are manifestations of quark effects. The role of triton clustering in very neutron rich nuclei is emphasized. All these require the concept of hidden colour states which arise from confinement ideas of QCD for the multi-quark systems. This provides comprehensive understanding of diverse nuclear …
The single particle and bulk properties of the neutron-rich nuclei constrain fundamental issues in nuclear physics and nuclear astrophysics like the limits of existence of quantum many body systems (atomic nuclei), the equation of state of neutron-rich matter, neutron star, nucleosynthesis, evolution of stars, neutron star merging etc.. The state of the art of Coulomb breakup of the neutron-rich nuclei has been used to explore those properties. Unambiguous information on detailed components of the ground-state wave-function along with quantum numbers of the valence neutron of the nuclei have b…
We investigate the contributions of various reaction channels to the interaction, reaction, charge-changing and neutron-changing cross sections. The goal is to investigate the relation between microscopic interactions and the symmetry energy component of the equation of state (EoS) of interest for the structure of neutron stars. We have made a comparison of the neutron skins extracted from diverse experimental techniques with those obtained with Hartree-Fock-Bogoliubov calculations with 23 Skyrme and with 8 density-dependent interactions used in the relativistic mean field method. We have show…
Phenomenological approach to inhomogeneous nuclear matter is useful to describe fundamental properties of atomic nuclei and neutron star crusts in terms of the equation of state of uniform nuclear matter. We review a series of researches that we have developed by following this approach. We start with more than 200 equations of state that are consistent with empirical masses and charge radii of stable nuclei and then apply them to describe matter radii and masses of unstable nuclei, proton elastic scattering and total reaction cross sections off unstable nuclei, and nuclei in neutron star crus…
The complex nature of the nuclear forces generates a broad range and diversity of observational phenomena. Heavy nuclei, though orders of magnitude less massive than neutron stars, are governed by the same underlying physics, which is enshrined in the nuclear equation of state. Heavy nuclei are expected to develop a neutron-rich skin where many neutrons collect near the surface. Such a skin thickness is strongly sensitive to the poorly-known density dependence of the symmetry energy near saturation density. An accurate and model-independent determination of the neutron-skin thickness of heavy …
We investigate outer crust compositions for a wide range of magnetic field strengths, up to $B\simeq 4\times10^{18}$ G, employing the latest experimental nuclear masses supplemented with various mass models. The essential effects of the magnetic field are twoholds: 1) Enhancement of electron fraction, which is connected to that of protons via the charge neutrality condition, due to the Landau-Rabi quantization of electron motion perpendicular to the field, namely, neutron-richness is suppressed for a given pressure. As a result, 2) nuclei can exist at higher pressures without dripping out neut…
We study the Borromean nuclei formed by a core nucleus and two neutrons in a nonrelativistic effective field theory formalism considering both neutron-neutron and neutron-core interactions. We provide formulae of the charge and matter radii, and successfully reproduce the universal relation proposed by Hongo and Son based on the approximation of an infinite neutron-neutron scattering length and neglecting the neutron-core scattering. Once the realistic finite neutron-neutron and neutron-core scattering lengths are used, the charge and matter radii are influenced by the neutron-core channel in …
The $β$-decay half-lives of neutron-rich nuclei with $20 \leqslant Z \leqslant 50$ are systematically investigated using the newly developed fully self-consistent proton-neutron quasiparticle random phase approximation (QRPA), based on the spherical relativistic Hartree-Fock-Bogoliubov (RHFB) framework. Available data are reproduced by including an isospin-dependent proton-neutron pairing interaction in the isoscalar channel of the RHFB+QRPA model. With the calculated $β$-decay half-lives of neutron-rich nuclei a remarkable speeding up of $r$-matter flow is predicted. This leads to enhanced $r…
The nuclear fission of very neuron-rich nuclei related to the r-process is essential for the termination of nucleosynthesis flows on the nuclear chart and the final abundances. Nevertheless, most of the available fission data for the r-process calculations are based on theory predictions, including phenomenological treatments. In this study, we calculated a series of nuclear fission distribution for neutron-rich nuclei away from the beta-stability line. As most of these nuclei are experimentally unknown, we are based on theoretical calculations based on the dynamical fission model with the Lan…
We investigate deep inelastic scattering from He-3 and H-3 within a conventional convolution treatment of binding and Fermi motion effects. Using realistic Faddeev wave functions together with a nucleon spectral function, we demonstrate that the free neutron structure function can be extracted in deep-inelastic scattering from A=3 mirror nuclei, with nuclear effects canceling to within 2% for x < 0.85.
