We show that the charge radii of reflection-asymmetric nuclei calculated in the frame of the finite-range droplet model are in better agreement with measured charge radii when reflection asymmetry is taken into account. However discrepancies between experimental and calculated changes in mean square charge radii still remain for some isotopic chains. These discrepancies cannot be removed by empirically including dynamic contributions to the quadrupole deformation.

We have developed an efficient isospin projection method in the shell model Monte Carlo approach for isospin-conserving Hamiltonians. For isoscalar observables this method has the advantage of being exact sample by sample. It allows us to take into account the proper isospin dependence of the nuclear interaction, thus avoiding a sign problem that such an interaction introduces in unprojected calculations. We apply the method to calculate the isospin dependence of level densities in the complete $\mathit{pf}+g_{9/2}$ shell. We find that isospin-dependent corrections to the total level density are particularly important for $N~Z$ nuclei.

We present spectral calculations of nuclear matter properties including three-body forces. Within the in-medium $T$-matrix approach, implemented with the CD-Bonn and Nijmegen potentials plus the three-nucleon Urbana interaction, we compute the energy per particle in symmetric and neutron matter. The three-body forces are included via an effective density dependent two-body force in the in-medium $T$-matrix equations. After fine tuning the parameters of the three-body force to reproduce the phenomenological saturation point in symmetric nuclear matter, we calculate the incompressibility and the energy per particle in neutron matter. We find a soft equation of state in symmetric nuclear matter but a relatively large value of the symmetry energy. We study the the influence of the three-body forces on the single-particle properties. For symmetric matter the spectral function is broadened at all momenta and all densities, while an opposite effect is found for the case of neutrons only. Noticeable modification of the spectral functions are realized only for densities above the saturation density. The modifications of the self-energy and the effective mass are not very large and appear to be strongly suppressed above the Fermi momentum.

Nuclear level densities for ${}^{56,57}\mathrm{Fe}$ have been extracted from the primary $\gamma$-ray spectra using (${}^3\mathrm{He},\hspace{0.5em}{}^3{\mathrm{He}}^{\text{'}}\gamma$) and (${}^3\mathrm{He},\hspace{0.5em}\alpha \gamma$) reactions. Nuclear thermodynamic properties for ${}^{56}\mathrm{Fe}$ and ${}^{57}\mathrm{Fe}$ are investigated using the experimental level densities. These properties include entropy, Helmholtz free energy, caloric curves, chemical potential, and heat capacity. In particular, the breaking of Cooper pairs and single-quasiparticle entropy are discussed and shown to be important concepts for describing nuclear level density. Microscopic model calculations are performed for level densities of ${}^{56,57}\mathrm{Fe}$. The experimental and calculated level densities are compared. The average number of broken Cooper pairs and the parity distribution are extracted as a function of excitation energy for ${}^{56,57}\mathrm{Fe}$ from the model calculations.

Using a three-body model, we study the dependence of spectroscopic factors for the overlap integrals $\langle \mathrm{core}+N|\mathrm{core}+N+N\rangle$ on the binding energy of the core $+\hspace{0.5em}N$ subsystem, considering as prototypes ${}^6\mathrm{He}$, ${}^6\mathrm{Be}$, ${}^9\mathrm{Li}$, ${}^9\mathrm{C}$, ${}^{18}\mathrm{O}$, and ${}^{18}\mathrm{Ne}$. We show that at small $N$-core binding energies these spectroscopic factors can be strongly influenced by the geometrical mismatch between the two-body $N$-core wave function that stretches into the classically forbidden region and the spatially confined three-body function. This mismatch comes from the strong two-body correlations between the nucleons outside the core and due to the core recoil effects. The mismatch leads to symmetry breaking in mirror spectroscopic factors that in some cases can be large enough to be observed in nucleon removal reactions. It is also responsible for deviations of the ratios of mirror asymptotic normalization coefficients (ANCs) from the simple model-independent analytical estimates. We discuss the influence of such mirror symmetry breaking on the prediction of direct stellar ($p,\gamma$) reactions from the measured mirror neutron ANCs.

We have studied the effects of momentum-dependent interactions on the single-particle properties of hot asymmetric nuclear matter. In particular, the single-particle potential of protons and neutrons as well as the symmetry potential have been studied within a self-consistent model using a momentum-dependent effective interaction. In addition, the isospin splitting of the effective mass has been derived from the above model. In each case temperature effects have been included and analyzed. The role of the specific parametrization of the effective interaction used in the present work has been investigated. It has been concluded that the behavior of the symmetry potential depends strongly on the parametrization of the interaction part of the energy density and the momentum dependence of the regulator function. The effects of the parametrization have been found to be less pronounced on the isospin mass splitting.

Capture-fission cross sections were measured for the collision of the massive nucleus ${}^{132}\mathrm{Sn}$ with ${}^{96}\mathrm{Zr}$ at center-of-mass energies ranging from 192.8 to 249.6 MeV in an attempt to study fusion enhancement and hindrance in this reaction involving very neutron-rich nuclei. Coincident fission fragments were detected using silicon detectors. Using angle and energy conditions, deep inelastic scattering events were separated from fission events. Coupled-channels calculations can describe the data if the surface diffuseness parameter, $a$, is allowed to be 1.10 fm instead of the customary 0.6 fm. The measured capture-fission cross sections agree moderately well with model calculations using the dinuclear system model. If we use this model to predict fusion barrier heights for these reactions, we find the predicted fusion hindrance, as represented by the extra push energy, is greater for the more neutron-rich system, lessening the advantage of the lower interaction barriers with neutron-rich projectiles.

α-particle evaporation spectra and $\gamma$-ray multiplicities were measured for various target-projectile systems corresponding to residual nuclei in the range of $Z_R=48\text{−}55$ and with excitation energy in the range of 30–40 MeV. The high-energy part of the evaporation spectra were analyzed using the statistical model code PACE2 to derive values of the inverse level-density parameter $(K)$. The $K$ values were found to be in the range of 9.0–10.5 for all systems. Angular momentum dependence of the inverse level-density parameter was investigated using the $\gamma$-ray multiplicity data. It is seen that there are strong variations in $K$ as a function of angular momentum for many systems. Present results provide important input information for a systematic understanding of the statistical properties of nuclei at moderate excitation energies and angular momenta.

On the basis of the statistical theory of a neutron-induced light nucleus reaction, a new kerma coefficient calculation formula, expressed as $k_{\Phi }=N\sum _{\mathit{ijk}}{\overline{E}}_{\mathit{ijk}}(E_n){\sigma }_{\mathit{ijk}}(E_n)$, is developed in this paper. In an analysis of the $n+{}^{12}\mathrm{C}$ and $n+{}^{16}\mathrm{O}$ reactions below 30 MeV, the average energies ${\overline{E}}_{\mathit{ijk}}$ of emitted particles of all kinds in the laboratory frame are derived in detail for different channels, allowing an exact energy balance. The optical model parameters of neutron and charged particles, which had reproduced very well the outgoing neutron double-differential cross sections in our early works, are used to obtain the cross sections ${\sigma }_{\mathit{ijk}}$. The calculated partial, elastic recoil, and total kerma coefficients for carbon and oxygen are consistent with existing experimental kerma coefficient data. The elastic cross sections and the first Legendre coefficients of elastic angular distribution derived from EBDF/B-VIIb3 are used in this paper to improve significantly the elastic recoil and total kerma coefficients.

We present a quantum-mechanical description of quark-hadron fragmentation in a nuclear environment. It employs the path-integral formulation of quantum mechanics, which takes care of all phases and interferences and contains all relevant time scales, such as production, coherence, and formation. The cross section includes the probability of prehadron (colorless dipole) production both inside and outside the medium. Moreover, it also includes inside-outside production, which is a typical quantum-mechanical interference effect (like twin-slit electron propagation). We observe a substantial suppression caused by the medium, even if the prehadron is produced outside the medium and no energy loss is involved. This important source of suppression is missed in the usual energy-loss scenario interpreting the effect of jet quenching observed in heavy ion collisions. This may be one reason for the too large gluon density reported by such analyses.

We perform the calculation of the nucleon dipole magnetic moment in full detail using the Gordon decomposition of the free quark current. This calculation has become necessary because of frequent misuse of the Gordon decomposition by some authors in computing the nucleon dipole magnetic moment.

The ${}^{197}\mathrm{Au}(\gamma ,n)$ reaction is used as an activation standard for photodisintegration studies on astrophysically relevant nuclei. At the bremsstrahlung facility of the superconducting electron accelerator ELBE (Electron Linear accelerator of high Brilliance and low Emittance) of Forschungszentrum Dresden-Rossendorf, photoactivation measurements on ${}^{197}\mathrm{Au}$ have been performed with bremsstrahlung endpoint energies from 8.0 to 15.5 MeV. The measured activation yield is compared with previous experiments as well as with calculations using Hauser-Feshbach statistical models. It is shown that the experimental data are best described by a two-Lorentzian parametrization with taking the axial deformation of ${}^{197}\mathrm{Au}$ into account. The experimental ${}^{197}\mathrm{Au}(\gamma ,n)$ reaction yield measured at ELBE via the photoactivation method is found to be consistent with previous experimental data using photon scattering or neutron detection methods.

Data from three experiments using the heavy-ion fusion evaporation-reaction ${}^{36}\mathrm{Ar}+{}^{28}\mathrm{Si}$ have been combined to study high-spin states in the residual nucleus ${}^{60}\mathrm{Ni}$, which is populated via the evaporation of four protons from the compound nucleus ${}^{64}\mathrm{Ge}$. The GAMMASPHERE array was used for all the experiments in conjunction with a $4\pi$ charged-particle detector arrays (MICROBALL, LUWUSIA) and neutron detectors (NEUTRON SHELL) to allow for the detection of $\gamma$ rays in coincidence with the evaporated particles. An extended ${}^{60}\mathrm{Ni}$ level scheme is presented, comprising more than $270\gamma$-ray transitions and 110 excited states. Their spins and parities have been assigned via directional correlations of $\gamma$ rays emitted from oriented states. Spherical shell-model calculations in the $\mathit{fp}$-shell characterize some of the low-spin states, while the experimental results of the rotational bands are analyzed with configuration-dependent cranked Nilsson-Strutinsky calculations.

Neutron-deficient astatine and francium nuclei were produced in the reaction ${}^{30}\mathrm{Si}+{}^{181}\mathrm{Ta}\to {}^{211}{\mathrm{Fr}}^{*}$ at 152 MeV. The evaporation residues from this very fissile system were selected with the HERCULES-II detector system and residue-gated $\gamma$ rays were measured with Gammasphere. Excited states were observed for the first time in ${}^{205,207}\mathrm{Fr}$, as well as sequences of low-energy transitions between high-spin states in ${}^{204}\mathrm{At}$ and ${}^{206}\mathrm{Fr}$. These latter structures have properties similar to those associated with magnetic rotation (shears bands) in lead nuclei. Comparisons with established shears bands are presented and prospects for the magnetic-rotation phenomenon near the predicted $N=120$ “magic” number are explored.

The lowest six excited $2^{+}$ levels of the even-even ${}^{122-130}\mathrm{Te}$ nuclei have been investigated using γ-ray spectroscopy following inelastic neutron scattering. These levels have been identified and their decay properties have been characterized from γ-ray excitation functions and γ-ray angular distributions; additionally, lifetimes of these levels have been deduced using the Doppler-shift attenuation method. Electromagnetic transition rates and $E2/M1$ multipole mixing ratios from the $2_x^{+}[x=2\text{−}6]\to 2_1^{+}$ transitions have been examined to identify the lowest mixed-symmetry states in these nuclei. In each nucleus, the mixed-symmetry strength appears to be fragmented between more than one level. The summed $M1$ strength from the $2_x^{+}$ [$x=2\text{−}6$] states to the $2_1^{+}$ level agrees rather well with neutron-proton interacting boson model predictions in the U(5) or O(6) limits for these Te nuclei.

We investigate the $\alpha$-decay half-lives of ground and isomeric states of exotic nuclei around the shell closures $Z=82$ and $N=82$ by the density-dependent cluster model (DDCM). Our calculations concentrate on four kinds of favored $\alpha$ transitions: (1) ground state to ground state, (2) ground state to isomeric state, (3) isomeric state to ground state, and (4) isomeric state to isomeric state. The calculated $\alpha$-decay half-lives of both ground and isomeric states are found to be in good agreement with the experimental data. Useful predictions on the partial half-lives of several $\alpha$ emitters are made for future experiments.

Quantitative evidence of the spherical-to-deformed shape phase transition near $N=90$ is given using the model-independent quadrupole shape invariant $q_2$, which provides a measure of the $\beta$ deformation of a given nucleus. This shape invariant is obtained using experimental $B(E2)$ values for the ground state band and first excited $0^{+}$ band of Gd isotopes around $N=90$, and is compared to calculations within the interacting boson model. Near the shape phase transition, the ground and excited $0^{+}$ band deformations are observed to cross.

Detailed structure calculations in ${}_{{\Xi }^{-}}^{12}\mathrm{Be}$, ${}_{{\Xi }^{-}}^5\mathrm{H}$, ${}_{{\Xi }^{-}}^9\mathrm{Li}$, ${}_{{\Xi }^{-}}^7\mathrm{H}$, and ${}_{{\Xi }^{-}}^{10}\mathrm{Li}$ are performed within the framework of the microscopic two-, three-, and four-body cluster models using the Gaussian expansion method. We adopted effective $\Xi N$ interactions derived from the Nijmegen interaction models, which give rise to substantially attractive Ξ-nucleus potentials in accordance with the experimental indications. ${}_{{\Xi }^{-}}^7\mathrm{H}$ and ${}_{{\Xi }^{-}}^{10}\mathrm{Li}$ are predicted to have bound states. we propose to observe the bound states in future $(K^{-},K^{+})$ experiments using ${}^7\mathrm{Li}$ and ${}^{10}\mathrm{B}$ targets in addition to the standard ${}^{12}\mathrm{C}$ target. The experimental confirmation of these states will provide information on the spin- and isospin-averaged $\Xi N$ interaction.

The influence of the electron cloud on the $\alpha$ decay constant is estimated by using relativistic electron binding energies to be a few per mil with an uncertainty of about one per mil. A few nuclides are suggested for measuring this influence in a storage ring.

Within the dinuclear system model, the effects of the relative orientations of interacting deformed nuclei on the interaction potential energy surfaces, the evaporation residue cross sections of some cold fusion reactions leading to superheavy elements are investigated. The competition between fusion and quasifission is studied to show the effect of the orientation. It turns out that the belly-belly orientation is in favor of the production of superheavy nuclei, because in the case a barrier has suppressed the quasifission and thus helped fusion.