Analysis of the recently obtained experimental data for a lot of collective states of ${}^{160}\mathrm{Dy}$ is presented. Classification of the low-lying states with positive parity $0^{+},2^{+},4^{+},6^{+}$ is performed. The energies of rotational high-spin states of the ground, $S,\gamma$ and two negative-parity bands are described in the framework of the interacting vector boson model. The energies of the bands are reproduced with high accuracy using only one set of model parameters for all bands. A more detailed investigation of the results is performed by calculation and comparison with experiment of the high-order odd-even staggering effects between states from different pairs of bands.

The dynamical effects of the entrance channel on the formation of the evaporation residues are studied by analyzing the ${}^{40}\mathrm{Ar}+{}^{176}\mathrm{Hf}$, ${}^{86}\mathrm{Kr}+{}^{130,136}\mathrm{Xe}$, ${}^{124}\mathrm{Sn}+{}^{92}\mathrm{Zr}$, and ${}^{48}\mathrm{Ca}+{}^{174}\mathrm{Yb}$ reactions leading to the ${}^{216}\mathrm{Th}{}^{*}$ and ${}^{222}\mathrm{Th}{}^{*}$ compound nuclei. We find that the difference between the evaporation residue cross sections for the reactions leading to the same compound nucleus is caused by the different angular momentum distributions of the partial fusion cross sections ${\sigma }_{\mathrm{fus}}^{\ell }(E_{c.m.})$. The strong dependence of the fusion angular momentum distribution on the mass (charge) asymmetry and shell structure of reactants is demonstrated. The effect of the $A/Z$ ratio for the ${}^{86}\mathrm{Kr}+{}^{130,136}\mathrm{Xe}$ reactions is discussed. The dynamical conditions of capture affect the competition between complete fusion and quasifission and, consequently, the shape of the angular momentum distribution of the compound nucleus. By this way the peculiarities of the entrance channel also affect the fission-evaporation competition of the excited intermediate nuclei along the deexcitation cascade of the compound nucleus and, consequently, the evaporation residue formation.

Coulomb and mass difference corrections to low-energy pion-nucleon scattering are calculated and compared with previous work including potential models, dispersion relation methods, and chiral perturbation theory calculations. Particular attention is paid to their role in testing isospin breaking.

An improvement in the treatment of the isovector channel of relativistic mean field (RMF) models based on effective field theory (E-RMF) is suggested, by adding an isovector scalar (δ) meson and using a similar procedure to the one used by Horowitz and Piekarewicz to adjust the isovector-vector channel in order to achieve a softer density dependent symmetry energy of the nuclear matter at high density. Their effects on the equation of state (EOS) at high density and on the neutrino mean free path (NMFP) in neutron stars are discussed.

An ab initio calculation of the ${}^4\mathrm{He}(e,e^{\text{'}}p$)${}^3\mathrm{H}$ longitudinal response is presented. The full four-body final-state interaction is taken into account by using an integral transform approach with a Lorentzian kernel. The semirealistic nucleon-nucleon potential MTI-III, including the Coulomb force, is the only ingredient of the calculation. The reliability of the direct knock-out hypothesis is discussed in both parallel and nonparallel kinematics. In the former case, lower missing momenta and higher momentum transfers are found to minimize effects beyond the plane-wave impulse approximation. For nonparallel kinematics, the role of antisymmetrization and the final-state interaction become more and more important as the missing momentum increases, raising doubts about the possibility of extracting momentum distributions and spectroscopic factors. The comparison with experimental data is discussed for parallel kinematics, in which a Rosenbluth separation is possible.

The set of parameters for α-nucleus potential is derived by using the data for both the α-decay half-lives and the fusion cross sections around the barrier for reactions $\alpha +$${}^{40}\mathrm{Ca}$, $\alpha +$${}^{59}\mathrm{Co}$, and $\alpha +$${}^{208}\mathrm{Pb}$. The α-decay half-lives are obtained in the framework of a cluster model using the WKB approximation. The evaluated α-decay half-lives and the fusion cross sections agreed well with the data. Fusion reactions between α particles and heavy nuclei can be used for both the formation of very heavy nuclei and spectroscopic studies of the formed compound nuclei.

We have studied the properties of low-lying levels in ${}^7\mathrm{He}$ using the ${}^2\mathrm{H}$$($${}^6\mathrm{He}$$,p)$${}^7\mathrm{He}$ reaction at 11.5 MeV/u. This reaction probes the ${}^6\mathrm{He}{}_{g.s.}+n$ character of states in ${}^7\mathrm{He}$. The ground state was populated with a spectroscopic factor comparable to that obtained from ab initio calculations, supporting the tentative spin-parity assignment of ${3/2}^{-}$ in the literature. In addition to the ground state, a broad structure is observed between $E_X=2–3$ MeV, the excitation-energy range expected for the ${1/2}^{-}$ state in ${}^7\mathrm{He}$. No evidence was found for a lower-lying, first-excited state reported recently.

A microscopic model aimed at the description of charge-exchange nuclear excitations along isotopic chains which include open-shell systems is developed. It consists of the quasiparticle random phase approximation (QRPA) made on top of Hartree-Fock-Bardeen-Cooper-Schrieffer (HF-BCS). The calculations are performed by using the Skyrme interaction in the particle-hole channel and a zero-range, density-dependent pairing force in the particle-particle channel. At variance with the (many) versions of QRPA which are available in the literature, in our work special emphasis is put on the full self-consistency. Its importance, as well as the role played by the charge-breaking terms of the nuclear Hamiltonian, like the Coulomb interaction, the charge symmetry and charge independence breaking (CSB-CIB) forces and the electromagnetic spin-orbit, are elucidated by means of numerical calculations of the isobaric analog resonances (IAR). The theoretical energies of these states along the chain of the Sn isotopes agree well with the experimental data in the stable isotopes. Predictions for unstable systems are presented.

The structure of deformed single-particle wave functions in the vicinity of zero energy limit is studied using a schematic model with a quadrupole deformed finite square-well potential. For this purpose, we expand the single-particle wave functions in multipoles and seek for the bound state and the Gamow resonance solutions. We find that, for the $K^{\pi }=0^{+}$ states, where K is the $z$-component of the orbital angular momentum, the probability of each multipole components in the deformed wave function is connected between the negative energy and the positive energy regions asymptotically, although it has a discontinuity around the threshold. This implies that the $K^{\pi }=0^{+}$ resonant level exists physically unless the $l=0$ component is inherently large when extrapolated to the well bound region. The dependence of the multipole components on deformation is also discussed.

The angular-momentum dependence of parity splitting in ground-state alternating parity bands and especially the sign inversion of parity splitting are considered. It is shown that the complicated odd-even staggering structure of the alternating parity bands can be interpreted as the result of two simultaneously manifesting effects: (1) penetration of the barrier separating two minima with the opposite signs of the reflection asymmetric deformation and (2) alignment of the angular momentum of the intrinsic excitations.

In this paper we study energy centroids such as those with fixed spin and isospin and those with fixed irreducible representations for both bosons and fermions, in the presence of random two-body and/or three-body interactions. Our results show that regularities of energy centroids of fixed-spin states reported in earlier works are very robust in these more complicated cases. We suggest that these behaviors might be intrinsic features of quantum many-body systems interacting by random forces.

The $\gamma$ decay of the nuclei ${}^{124,125}\mathrm{Ba}$ has been investigated by means of the EUROBALL spectrometer, coupled to the DIAMANT array of charged-particle detectors, using the reaction ${}^{64}\mathrm{Ni}$ + ${}^{64}\mathrm{Ni}$ at $E_{\mathrm{beam}}=255$ and 261 MeV. In the nucleus ${}^{125}\mathrm{Ba}$ six new E1 transitions have been found to link opposite-parity bands currently interpreted as $\nu d_{5/2}$(+$g_{7/2}),\nu h_{11/2}$ structures. The previously unknown $J^{\pi }=3^{-}$ level in the nucleus ${}^{124}\mathrm{Ba}$ has also been identified; its excitation energy is accurately reproduced by a microscopic calculation including octupole correlations. Both issues are bolstered by sizable $B(E1)/B(E2)$ ratios.

A precise value for the magnetic moment of the ${}^{69}\mathrm{As}$ $5/2^{-}$ ground state has been obtained from nuclear magnetic resonance on oriented nuclei (NMR/ON) using the NICOLE ${}^3\mathrm{He}$-${}^4\mathrm{He}$ dilution refrigerator setup at ISOLDE/CERN. The NMR/ON signal was observed by monitoring the anisotropy of the ${}^{69}\mathrm{As}$ β particles. The center frequency $\nu [B_{\mathrm{ext}}=0.0994(10)T]=169.98(9)$ MHz corresponds to $\mu [$${}^{69}\mathrm{As}$$]=+1.6229(16){\mu }_N$. This result differs considerably from the $\pi f_{5/2}$ single-particle value obtained with g factors for a free proton but is in reasonable agreement with the value obtained with effective g factors and with values from a core polarization calculation and from calculations in the framework of the interacting boson-fermion model. Assuming a single exponential spin-lattice relaxation behavior a relaxation time $T_1^{\text{'}}=10(25)$ s was observed for ${}^{69}\mathrm{As}$$\underset{¯}{\mathrm{Fe}}$ at a temperature of about 20 mK in a magnetic field $B=0.1$ T.

Nucleon-nucleon (NN) cross sections are evaluated in neutron-rich matter using a scaling model according to density, momentum, and isospin dependent nucleon effective masses. It is found that the in-medium NN cross sections are not only reduced but also have a different isospin dependence compared with the free-space ones. Because of the neutron-proton effective mass splitting the difference between nn and pp scattering cross sections increases with the increasing isospin asymmetry of the medium. Within the transport model IBUU04, the in-medium NN cross sections are found to influence significantly the isospin transport in heavy-ion reactions. With the in-medium NN cross sections, a symmetry energy of $E_{\mathrm{sym}}(\rho )\approx 31.6(\rho /{\rho }_0){}^{0.69}$ was found most acceptable compared with both the MSU isospin diffusion data and the presently acceptable neutron-skin thickness in ${}^{208}\mathrm{Pb}$. The isospin dependent part $K_{\mathrm{asy}}({\rho }_0)$ of isobaric nuclear incompressibility was further narrowed down to $-500\pm 50$ MeV. The possibility of determining simultaneously the in-medium NN cross sections and the symmetry energy was also studied. The proton transverse flow, or even better the combined transverse flow of neutrons and protons, can be used as a probe of the in-medium NN cross sections without much hindrance from the uncertainties of the symmetry energy.

The nuclear system ${}^5\mathrm{H}$ was studied using the ${}^3\mathrm{H}$($t,p$)${}^5\mathrm{H}$ transfer reaction at a laboratory energy of 57.7 MeV and small center of mass angles. The energy and angular correlations among the ${}^5\mathrm{H}$ decay fragments were obtained by complete kinematical reconstruction. A broad structure in the ${}^5\mathrm{H}$ missing mass spectrum above 2.5 MeV with a typical width of several MeV was identified as a mixture of $3/2^{+}$ and $5/2^{+}$ states. Analysis of interference patterns observed in the measured angular correlations disclosed the $1/2^{+}$ ground state of ${}^5\mathrm{H}$ concealed in the smooth missing mass spectrum. The deduced values for the resonance energy and width are $E_{g.s.}\approx 1.8$ MeV and ${\Gamma }_{g.s.}\approx 1.3$ MeV. The estimated cross sections for population of the ground state and the doublet of excited states at ${\theta }_{c.m.}=5^{°}-{10}^{°}$ are $150\pm 50$ μb/sr and $4.6\pm 2$ mb/sr, respectively.

We investigate hard photon production in a chemically equilibrating quark-gluons plasma with finite baryon density at one-loop and two-loop based on Jüttner distribution of partons of the system. We find that the photon yield increases obviously with increasing the initial quark chemical potential, and the photon production is dominated by early times. In addition, obvious difference between the calculated production and the one in the thermodynamic equilibrium system shows that the study of photon production in the chemically equilibrating system is very significant.

We explore the suitability of a modern vector meson dominance (VMD) model as a method for chiral extrapolation of nucleon electromagnetic form factor simulations in lattice QCD. It is found that the VMD fits to experimental data can be readily generalized to describe the lattice simulations. However, the converse is not true. That is, the VMD form is unsuitable as a method of extrapolation of lattice simulations at large quark mass to the physical regime.

It is argued that in the antiproton-proton annihilation into two mesons, $\overline{p}p\to m_1{m}_2$, the origin of different restrictive angular momentum selection rules commonly obtained for planar annihilation diagrams $A2$ and for non-planar rearrangement diagrams $R2$ lies in the omission of momentum transfer between an annihilated antiquark-quark pair and a remaining quark or antiquark. If momentum transfer is included, there is no reason for dismissing one type of diagram in favor of another one. Some considerations in the large-$N_c$ limit of QCD equally shed light on the planar and non-planar contributions to the total $\overline{N}N\to m_1{m}_2$ annihilation amplitude.

Continuum effects for pairing correlations and low-frequency vibrational excitations in nuclei close to the neutron drip line are investigated by use of the coordinate space Hartree-Fock-Bogoliubov and quasiparticle random-phase approximation calculations. It is shown that quasiparticle states with small orbital angular momentum $\ell$ acquire significant changes of the spatial structure by the pairing correlations and the coupling to continuum states, and they cause the spatially extended distribution of the pairing density that enhances the pairing energy. By a similar mechanism, the spatially extended structure of the two-quasiparticle states among low-$\ell$ neutrons is realized, and it brings about the strong transition strength of the low-frequency vibrational excitations around the neutron drip line.

Correlations between the thickness of the neutron skin in finite nuclei and the nuclear matter symmetry energy are studied in the Skyrme Hartree-Fock model. From the most recent analysis of the isospin diffusion data in heavy-ion collisions based on an isospin- and momentum-dependent transport model with in-medium nucleon-nucleon cross sections, a value of $L=88\pm 25$ MeV for the slope of the nuclear symmetry energy at saturation density is extracted, and this imposes stringent constraints on both the parameters in the Skyrme effective interactions and the neutron skin thickness of heavy nuclei. Predicted thickness of the neutron skin is $0.22\pm 0.04$ fm for ${}^{208}\mathrm{Pb}$, $0.29\pm 0.04$ fm for ${}^{132}\mathrm{Sn}$, and $0.22\pm 0.04$ fm for ${}^{124}\mathrm{Sn}$.