A comprehensive analysis of multiparticle emissions following photon induced reactions at intermediate energies is provided. Photon induced reaction is described in the energy range of $~30\text{−}140$ MeV with an approach based on the quasideuteron nuclear photoabsorption model followed by the process of competition between light particle evaporation and fission for the excited nucleus. The evaporation-fission process of the compound nucleus is simulated in a Monte-Carlo framework. The study shows almost no fission events for the medium mass nuclei and reproduces the available experimental data of photonuclear reaction cross sections satisfactorily at energies $~30\text{−}140$ MeV.

A recently developed two-level mixing model of the decay out of superdeformed bands is applied to examine the loss of flux from the yrast superdeformed bands in ${}^{192}\mathrm{Pb}$, ${}^{194}\mathrm{Pb}$, and ${}^{196}\mathrm{Pb}$. Probability distributions for decay to states at normal deformations are calculated at each level. The sensitivity of the results to parameters describing the levels at normal deformation and their coupling to levels in the superdeformed well is explored. It is found that except for narrow ranges of the interaction strength coupling the states, the amount of intensity lost is primarily determined by the ratio of $\gamma$ decay widths in the normal and superdeformed wells. It is also found that while the model can accommodate the observed fractional intensity loss profiles for decay from bands at relatively high excitation, it cannot accommodate the similarly abrupt decay from bands at lower energies if standard estimates of the properties of the states in the first minimum are employed.

Full Faddeev-type calculations are performed for one-neutron knockout reaction of ${}^{14}\mathrm{Be}$ on proton target at 69 MeV/nucleon incident energy. Inclusive transverse momentum distributions for the outgoing $({}^{12}\mathrm{Be}+n)$ system and semi-inclusive cross sections are presented. A significant proton-core single scattering contribution emerges where the valence neutron has nonzero angular momentum relative to the core. This indicates that distorted-wave impulse approximation is inadequate and the complete multiple scattering series must be taken into account for the considered reaction. The magnitude of the semi-inclusive cross section at quasifree scattering conditions is a clear signature of the angular momentum of the valence nucleon.

We investigate the early onset of pionic color transparency (πCT) observed at Jefferson Laboratory (JLAB) in semi-exclusive pion electroproduction reaction $A(e,e^{\text{'}}{\pi }^{+})$ off nuclei. In the present description the primary ${\gamma }^{*}p\to {\pi }^{+}n$ interaction is described very well both for the longitudinal and the transverse polarizations. For the final state interactions a coupled-channel treatment of the interactions of transmitted hadrons allows to go beyond the Glauber approximation. We show that a proper distinction between the soft hadronic and hard partonic components of the electroproduction amplitude is essential for a quantitative description of the measured nuclear transparency. The data are well reproduced if one assumes that point-like configurations are produced in the regime of hard deep-inelastic scattering (DIS) off partons and dominate the transverse channel.

Total cross sections for the quasifree $\mathit{pn}\to \mathit{pn}\eta$ reaction in the range from the kinematical threshold up to 20 MeV excess energy have been determined. At threshold they exceed corresponding cross sections for the $\mathit{pp}\to \mathit{pp}\eta$ reaction by a factor of about 3 in contrast to the factor of 6 established for higher excess energies. To large extent, the observed decrease of the ratio $\sigma (\mathit{pn}\to \mathit{pn}\eta )/\sigma (\mathit{pp}\to \mathit{pp}\eta )$ toward threshold may be assigned to the different energy dependence of the proton-proton and proton-neutron final-state interactions. The experiment was conducted using a proton beam of the cooler synchrotron COSY and a cluster jet deuteron target. The proton-neutron reactions were tagged by the spectator proton whose momentum was measured for each event. Protons and neutron outgoing from the $\mathit{pn}\to \mathit{pn}\eta$ reaction have been registered by means of the COSY-11 facility, an apparatus dedicated for threshold meson production.

The scattering of 30 MeV ${}^3\mathrm{He}$ from a ${}^{185}\mathrm{Re}$ target has been investigated. The measured elastic scattering is in disagreement with calculations using common optical model parameter sets found in the literature. A new optical model parameter set has been determined that reproduces the data for both the elastic and the inelastic scattering channels.

A simple jet absorption model is used to study the influence of hadron pairs produced by quenched jets, on di-hadron angular correlations at intermediate transverse momentum $(p_T)$. We demonstrate that such pairs can dominate both the yield and the shape of angular correlations, and may account for the similar properties between the near-side “ridge” and the away-side “double-humped” structure seen in recent data. These hadron pairs also show azimuthal anisotropy which is sensitive to the emission angle of hadrons relative to that of the jet. Measurement of this anisotropy may provide a constraint for elucidating the production mechanism for near- and away-side hadron pairs at intermediate $p_T$.

We perform no-core full configuration calculations for a set of light nuclei including ${}^{16}\mathrm{O}$ with a realistic $\mathit{NN}$ interaction, JISP16. We obtain ground-state energies and their uncertainties through exponential extrapolations that we demonstrate are reliable in ${}^2\mathrm{H}$, ${}^3\mathrm{H}$, and ${}^4\mathrm{He}$ test cases where fully converged results are obtained directly. We find that ${}^6\mathrm{He}$, ${}^6\mathrm{Li}$, and ${}^8\mathrm{He}$ are underbound by about 600 keV, 560 keV, and $1.7$ MeV, respectively. ${}^{12}\mathrm{C}$ is overbound by about $1.7$ MeV and ${}^{16}\mathrm{O}$ is overbound by about 16 MeV. The first excited $0^{+}$ states in ${}^{12}\mathrm{C}$ and ${}^{16}\mathrm{O}$ are also evaluated but their uncertainties are significantly larger than the uncertainties for the ground states.

At the radioactive ion beam facility REX-ISOLDE, neutron-rich zinc isotopes were investigated using low-energy Coulomb excitation. These experiments have resulted in $B(E2,2_1^{+}\to 0_1^{+})$ values in ${}^{74-80}\mathrm{Zn}$, $B(E2,4_1^{+}\to 2_1^{+})$ values in ${}^{74,76}\mathrm{Zn}$ and the determination of the energy of the first excited $2_1^{+}$ states in ${}^{78,80}\mathrm{Zn}$. The zinc isotopes were produced by high-energy proton- $(A=74,76,80)$ and neutron- $(A=78)$ induced fission of ${}^{238}\mathrm{U}$, combined with selective laser ionization and mass separation. The isobaric beam was postaccelerated by the REX linear accelerator and Coulomb excitation was induced on a thin secondary target, which was surrounded by the MINIBALL germanium detector array. In this work, it is shown how the selective laser ionization can be used to deal with the considerable isobaric beam contamination and how a reliable normalization of the experiment can be achieved. The results for zinc isotopes and the $N=50$ isotones are compared to collective model predictions and state-of-the-art large-scale shell-model calculations, including a recent empirical residual interaction constructed to describe the present experimental data up to 2004 in this region of the nuclear chart.

The neutron-rich isotopes with $Z⩽20$, in particular those with neutron numbers around $N=28$, have been the focus of a lot experimental and theoretical scrutiny during the past few years. Shell-model calculations using the effective interaction SDPF-NR were able to predict or to explain most of the properties featured by these nuclei. Prominent among them is the disappearance of the $N=28$ shell closure for $Z⩽16$. We have incorporated into SDPF-NR some modifications, either on purely theoretical grounds or guided by new experimental information. The proposed interaction SDPF-U offers enhanced reliability with respect to the earlier version.

The projected configuration interaction method starts from a collection of mean-field wave functions and builds up correlated wave functions of good symmetry. It relies on the generator coordinator method techniques, but it improves the past approaches by a very efficient method of selecting the basis states. We use the same realistic Hamiltonians and model spaces as the configuration interaction (CI) method and compare the results with the full CI calculations in the $\mathit{sd}$ and $\mathit{pf}$ shell. Examples of ${}^{24}\mathrm{Mg}$, ${}^{28}\mathrm{Si}$, ${}^{48}\mathrm{Cr}$, ${}^{52}\mathrm{Fe}$, and ${}^{56}\mathrm{Ni}$ are discussed.

The ${\mathit{ppK}}^{-}$ system, as a prototype for possible quasibound $\overline{K}$ nuclei, is investigated using a variational approach. Several versions of energy-dependent effective $\overline{K}N$ interactions derived from chiral SU(3) dynamics are employed as input, together with a realistic $\mathit{NN}$ potential (Av18). Taking into account theoretical uncertainties in the extrapolations below the $\overline{K}N$ threshold, we find that the antikaonic dibaryon ${\mathit{ppK}}^{-}$ is not deeply bound. With the driving $s$-wave $\overline{K}N$ interaction the resulting total binding energy is $B({\mathit{ppK}}^{-})=20\pm 3$ MeV and the mesonic decay width involving $\overline{K}N\to \pi Y$ is expected to be in the range 40–70 MeV. Properties of this quasibound ${\mathit{ppK}}^{-}$ system (such as density distributions of nucleons and antikaon) are discussed. The $\Lambda (1405)$, as an $I=0$ quasibound state of $\overline{K}$ and a nucleon, appears to survive in the ${\mathit{ppK}}^{-}$ cluster. Estimates are given for the influence of $p$-wave $\overline{K}N$ interactions and for the width from two-nucleon absorption $(\overline{K}\mathit{NN}\to \mathit{YN})$ processes. With inclusion of these effects and dispersive corrections from absorption, the ${\mathit{ppK}}^{-}$ binding energy is expected to be in the range 20–40 MeV, whereas the total decay width can reach 100 MeV but with large theoretical uncertainties.

A phenomenological study of quark-hadron duality in electron and neutrino scattering on nuclei is performed. We compute the structure functions $F_2$ and ${\mathit{xF}}_3$ in the resonance region within a framework that includes the Dortmund-group model for the production of the first four lowest-lying baryonic resonances and a relativistic mean-field model for nuclei. We consider four-momentum transfers between 0.2 and 2.5 ${\mathrm{GeV}}^2$. The results indicate that nuclear effects play a different role in the resonance and deep inelastic scattering (DIS) region. We find, that local duality does not work well. In the studied range of four-momentum transfers, the computed nuclear structure functions slide along the DIS curve; the integrated strength in the resonance region, however, is considerably lower than the DIS one.

Nuclei in dense matter are influenced by the medium. In the cluster mean-field approximation, an effective Schrödinger equation for the $A$-particle cluster is obtained accounting for the effects of the correlated medium such as self-energy, Pauli blocking, and Bose enhancement. Similar to the single-baryon states (free neutrons and protons), the light elements ($2⩽A⩽4$, internal quantum state ν) are treated as quasiparticles with energies $E_{A,\nu }(\mathbf{P};T,n_n,n_p)$. These energies depend on the center-of-mass momentum $\mathbf{P}$, as well as temperature $T$ and the total densities $n_n$, $n_p$ of neutrons and protons, respectively. No $\beta$ equilibrium is considered so that $n_n$, $n_p$ (or the corresponding chemical potentials ${\mu }_n$, ${\mu }_p$) are fixed independently. For the single-nucleon quasiparticle energy shift, different approximate expressions such as Skyrme or relativistic mean-field approaches are well known. Treating the $A$-particle problem in appropriate approximations, results for the cluster quasiparticle shifts are given. Properties of dense nuclear matter at moderate temperatures in the subsaturation density region considered here are influenced by the composition. This in turn is determined by the cluster quasiparticle energies, in particular the formation of clusters at low densities when the temperature decreases and their dissolution due to Pauli blocking as the density increases. Our finite-temperature Green function approach covers different limiting cases: the low-density region where the model of nuclear statistical equilibrium and virial expansions can be applied and the saturation-density region where a mean-field approach is possible.

Pion-nucleus bremsstrahlung offers a possibility of measuring the structure functions of pion-Compton scattering from a study of the small-momentum-transfer region where the bremsstrahlung reaction is dominated by the single-photon-exchange mechanism. The corresponding cross-section distribution is characterized by a sharp peak at small momentum transfers. But there is also a hadronic contribution that is smooth and constitutes an undesired background. In this article the modification of the single-photon-exchange amplitude by multiple Coulomb scattering is investigated as well as the Coulomb-nuclear interference term.

The relevance of equilibrium in a multifragmentation reaction of very central ${}^{40}\mathrm{Ca}$ $+$ ${}^{40}\mathrm{Ca}$ collisions at 35 MeV/nucleon is investigated by using simulations of antisymmetrized molecular dynamics (AMD). Two types of ensembles are compared. One is the reaction ensemble of the states at each reaction time $t$ in collision events simulated by AMD, and the other is the equilibrium ensemble prepared by solving the AMD equation of motion for a many-nucleon system confined in a container for a long time. The comparison of the ensembles is performed for the fragment charge distribution and the excitation energies. Our calculations show that there exists an equilibrium ensemble that well reproduces the reaction ensemble at each reaction time $t$ for the investigated period $80⩽t⩽300\hspace{0.5em}\mathrm{fm}/c$. However, there are some other observables that show discrepancies between the reaction and equilibrium ensembles. These may be interpreted as dynamical effects in the reaction. The usual static equilibrium at each instant is not realized since any equilibrium ensemble with the same volume as that of the reaction system cannot reproduce the fragment observables.

This paper reports on the most comprehensive data set obtained on differential and fully integrated cross sections for the process $ep\to e^{\text{'}}p{\pi }^{+}{\pi }^{-}$. The data were collected with the CLAS detector at Jefferson Laboratory. Measurements were carried out in the as yet unexplored kinematic region of photon virtuality $0.2<Q^2<0.6$ ${\mathrm{GeV}}^2$ and invariant mass of the final hadron system $W$ from 1.3 to 1.57 GeV. For the first time, nine independent one-fold differential cross sections were determined in each bin of $W$ and $Q^2$ covered by the measurements. A phenomenological analysis of the data allowed us to establish the most significant mechanisms contributing to the reaction. The nonresonant mechanisms account for a major part of cross sections. However, we find sensitivity to $s$-channel excitations of low-mass nucleon resonances, especially to the $N(1440)P_{11}$ and $N(1520)D_{13}$ states in kinematic dependencies of the one-fold differential cross sections.

We calculate the spin-dependent Fermi liquid parameters (FLPs), single-particle energies, and energy densities of various spin states of polarized quark matter. The expressions for the incompressibility $K$ and sound velocity $c_1$ in terms of the spin-dependent FLPs and polarization parameter ξ are derived. Estimated values of $K$ and $c_1$ reveal that the equation of state of the polarized matter is stiffer than the unpolarized one. Finally, we investigate the possibility of the spin polarization (ferromagnetism) phase transition.

We show the functional dependence of eigenvalues in terms of sorted diagonal elements of a Hamiltonian matrix in the nuclear shell model (NSM), a matrix with uniform distribution and that with normal distribution. For a realistic two-body interaction, its relation is approximately expressed by a linear function, especially for the most elements in the intermediate region. We also derive their functional dependences for the uniform distribution and the normal distribution analytically. As a special case, the functional relation for the normal distribution turns out to be approximated by a hyperbolic-tangent function.

We investigate the phase transition in odd nuclei within the Interacting Boson Fermion Model in correspondence with the transition from spherical to stable axially deformed shape. The odd particle is assumed to be moving in the single-particle orbitals with angular momenta $j=1/2,3/2,5/2$ with a boson-fermion Hamiltonian that leads to the occurrence of the ${\mathrm{SU}}^{\mathit{BF}}(3)$ boson-fermion symmetry when the boson part approaches the SU(3) condition. Both energy spectra and electromagnetic transitions show characteristic patterns similar to those displayed by the even nuclei at the corresponding critical point. The role of the additional particle in characterizing the properties of the critical points in finite quantal systems is investigated by resorting to the formalism based on the intrinsic frame.