We present the first implementation in the $(\beta ,\gamma )$ plane of the generator coordinate method with full triaxial angular momentum and particle number projected wave functions using the Gogny force. Technical details about the performance of the method and the convergence of the results in both the symmetry restoration and the configuration mixing parts are discussed in detail. We apply the method to the study of ${}^{24}\mathrm{Mg}$; the calculated energies of excited states as well as the transition probabilities are compared to the available experimental data, showing a good overall agreement. In addition, we present the RVAMPIR approach, which provides a good description of the ground and $\gamma$ bands in the absence of strong mixing.

Heavy quark production has been very well studied over the last years both theoretically and experimentally. Theory has been used to study heavy quark production in $ep$ collisions at HERA, in $\mathit{pp}$ collisions at Tevatron and RHIC, in $\mathit{pA}$ and $\mathit{dA}$ collisions at RHIC, and in $\mathit{AA}$ collisions at CERN-SPS and RHIC. However, to the best of our knowledge, heavy quark production in $\mathit{eA}$ has received almost no attention. With the possible construction of a high energy electron-ion collider, updated estimates of heavy quark production are needed. We address the subject from the perspective of saturation physics and compute the heavy quark production cross section with the dipole model. We isolate shadowing and nonlinear effects, showing their impact on the charm structure function and on the transverse momentum spectrum.

An interesting process of violent reseparation of a heavy nuclear system into three or four fragments of comparable size was recently observed in ${}^{197}\mathrm{Au}+{}^{197}\mathrm{Au}$ collisions at 15 MeV/nucleon. Combined analysis of the binary deep inelastic events and the ternary and quaternary breakup events demonstrates that the newly observed ternary and quaternary reactions belong to the same wide class of deep inelastic collisions as the conventional (binary) damped reactions. It is shown that the ternary and quaternary breakup reactions occur at extremely inelastic collisions corresponding to small impact parameters, while more peripheral collisions lead to well-known binary deep inelastic reactions.

The reaction dynamics of axisymmetric deformed ${}^{24}\mathrm{Mg}+{}^{24}\mathrm{Mg}$ collisions has been investigated systematically by an isospin-dependent quantum molecular dynamics model. It is found that different deformations and orientations result in apparently different properties of reaction dynamics. We reveal that some observables such as nuclear stopping power ($R$), multiplicity of fragments, and elliptic flow are very sensitive to the initial deformations and orientations. There exists an eccentricity scaling of elliptic flow in central body-body collisions with different deformations. In addition, the tip-tip and body-body configurations turn out to be two extreme cases in central reaction dynamical process.

Pure hadronic compact stars that are above a limiting value $(\approx 1.6M_{\odot })$ of their gravitational masses, to which predictions of most of other equations of state are restricted, can be reached from the equation of state (EOS) obtained using the density-dependent M3Y (DDM3Y) effective interaction. This effective interaction is found to be quite successful in providing a unified description of elastic and inelastic scattering, various radioactivities, and nuclear matter properties. We present a systematic study of the properties of pure hadronic compact stars. The $\beta$-equilibrated neutron star matter using this EOS with a thin crust is able to describe highly massive compact stars, such as PSR B1516$+$02B with a mass $M=1.{94}_{-0.19}^{+0.17}{M}_{\odot }$ and PSR J0751$+$1807 with a mass $M=2.1\pm 0.2M_{\odot }$ to a 1$\sigma$ confidence level.

The nuclear pairing condensate is expected to change character from spin singlet to spin triplet when the nucleus is very large and the neutron and proton numbers $Z,N$ are equal. We investigate the transition between these two phases within the framework of the Hartree-Fock-Bogoliubov equations, using a zero-range interaction to generate the pairing. We confirm that an extremely large nucleus would indeed favor triplet pairing condensates, with the Hamiltonian parameters taken from known systematics. The favored phase is found to depend on the specific orbitals at the Fermi energy. The smallest nuclei with a well-developed spin-triplet condensate are in the mass region $A~130–140$.

The empirical relativistic density-dependent, point-coupling energy density functional, adjusted exclusively to experimental binding energies of a large set of deformed nuclei with $A\approx 150–180$ and $A\approx 230–250$, is tested with spectroscopic data for ${}^{166}\mathrm{Er}$ and ${}^{240}\mathrm{Pu}$. Starting from constrained self-consistent triaxial relativistic Hartree-Bogoliubov calculations of binding energy maps as functions of the quadrupole deformation in the $\beta –\gamma$ plane, excitation spectra and $E2$ transition probabilities are calculated as solutions of the corresponding microscopic collective Hamiltonian in five dimensions for quadrupole vibrational and rotational degrees of freedom and compared with available data on low-energy collective states.

Kaonic hydrogen is studied with various realistic potentials in an accurate numerical approach based on Sturmian functions. It is found that the mass difference between the $K^{-}p$ and ${\mathrm{K̄}}^{0}n$ channels has a considerable effect on theoretical results of the energy shift and decay width of kaonic hydrogen. On average, the theoretical result in the isospin symmetry limit is smaller by a factor of about 20% than the full result where the mass difference between the $K^{-}p$ and ${\mathrm{K̄}}^{0}n$ channels is properly treated. The theoretical results based on realistic local potentials, which reproduce well scattering data, are inconsistent with the recent measurement of the energy shift and decay width of the $1s$ kaonic hydrogen state by the DEAR Collaboration.

We present a new theoretical approach to evaluate $\alpha$-decay properties of deformed nuclei, namely the multichannel cluster model (MCCM). The deformed $\alpha$-nucleus potential is taken into full account, and the coupled-channel Schrödinger equation with outgoing wave boundary conditions is employed for quasibound states. Systematic calculations are carried out for well-deformed even-even nuclei with $Z⩾98$ and isospin dependence of nuclear potentials is included in the calculations. Fine structure observed in $\alpha$ decay is well described by the four-channel microscopic calculation, which is performed for the first time in $\alpha$-decay studies. The good agreement between experiment and theory is achieved for both total $\alpha$-decay half-lives and branching ratios to the ground-state rotational band of daughter nuclei. Predictions on the branching ratios to high-spin daughter states are presented for superheavy nuclei, which may be important to interpret future observations.

An abrupt change in $\alpha$-decay systematics around the $N=126$ neutron shell closure is discussed. It is explained as a sudden hindrance of the clustering of the nucleons that eventually form the $\alpha$ particle. This is because the clustering induced by the pairing mode acting upon the four nucleons is inhibited if the configuration space does not allow a proper manifestation of the pairing collectivity.

We present a complete systematically theoretical study of multifragmentation for asymmetric colliding nuclei for heavy-ion reactions in the energy range between 50 MeV/nucleon and 600 MeV/nucleon by using soft and hard equations of state. This study is performed within an isospin-dependent quantum-molecular dynamics model. To see the effect of mass asymmetry, simulations are carried out in the absence of Coulomb interactions. Coulomb interactions enhance the production of fragments by about 20$\%$. We envision an interesting outcome for large asymmetric colliding nuclei. Although nearly symmetric nuclei depict a well-known trend for rising and falling with a peak around $E=100\hspace{0.5em}\mathrm{MeV}/\mathrm{nucleon}$, this trend, however, is completely missing for large asymmetric nuclei. Therefore, experiments are needed to verify this prediction.

Measurements of fusion for ${}^{9,10,11}\mathrm{Be}$ allow testing of the relative importance to fusion and breakup of the $\alpha$-cluster structure found in all these Be isotopes, compared with the neutron-halo structure only present for ${}^{11}\mathrm{Be}$. However, disagreements exist among different published experimental data sets for the reactions of ${}^{9,10,11}\mathrm{Be}$ with ${}^{209}\mathrm{Bi}$. Accurate measurements of above-barrier cross sections for the products of complete fusion (fission and evaporation residues) in the reaction of ${}^9\mathrm{Be}$ with ${}^{209}\mathrm{Bi}$ and ${}^{208}\mathrm{Pb}$ provide the basis for a reanalysis of above-barrier fusion for ${}^{10,11}\mathrm{Be}$$+$${}^{209}\mathrm{Bi}$. This includes procedures making full use of the higher precision stable beam data and resolves many of the disagreements. The improved self-consistency of the analysis allows investigation of the experimental average fusion barriers. Although showing some scatter, these suggest a higher barrier for the neutron halo nucleus ${}^{11}\mathrm{Be}$. Comparison of published cross sections for fusion associated with capture of all the charge of the projectile suggest that all these Be isotopes show significant suppression of complete fusion, a surprising result given that the $\alpha$-breakup threshold energies are $1.57$ MeV for ${}^9\mathrm{Be}$ but over 7 MeV for ${}^{10,11}\mathrm{Be}$. Further experimental studies to investigate in more detail the division between complete and incomplete fusion for reactions of ${}^{10,11}\mathrm{Be}$ are needed.

Pion production in nuclear collisions at the Super Proton Synchrotron (SPS) is investigated with the aim to search, in a restricted domain of the phase diagram, for power laws in the behavior of correlations that are compatible with critical QCD. We analyzed interactions of nuclei of different sizes ($\mathrm{p}+\mathrm{p}$, $\mathrm{C}+\mathrm{C}$, $\mathrm{Si}+\mathrm{Si}$, $\mathrm{Pb}+\mathrm{Pb}$) at $158A$ GeV adopting, as appropriate observables, scaled factorial moments in a search for intermittent fluctuations in transverse dimensions. The analysis is performed for ${\pi }^{+}{\pi }^{-}$ pairs with an invariant mass very close to the two-pion threshold. In this sector one may capture critical fluctuations of the sigma component in a hadronic medium, even if the $\sigma$ meson has no well-defined vacuum state. It turns out that for the $\mathrm{Pb}+\mathrm{Pb}$ system the proposed analysis technique cannot be applied without entering the invariant mass region with strong Coulomb correlations. As a result the treatment becomes inconclusive in this case. Our results for the other systems indicate the presence of power-law fluctuations in the freeze-out state of $\mathrm{Si}+\mathrm{Si}$ approaching in size the prediction of critical QCD.

Within the picture of jet quenching induced by multiple parton scattering and gluon bremsstrahlung, medium modification of parton fragmentation functions and therefore the suppression of large transverse-momentum hadron spectra are controlled by both the value and the space-time profile of the jet transport parameter along the jet propagation path. Experimental data on single-hadron suppression in high-energy heavy-ion collisions at the Relativistic Heavy Ion Collider energy are analyzed within the higher-twist (HT) approach to the medium-modified fragmentation functions and the next-to-leading order perturbative QCD parton model. Assuming that the jet transport parameter $\mathrm{q̂}$ is proportional to the particle number density in both quark gluon plasma (QGP) and hadronic phase, experimental data on jet quenching in deeply inelastic scattering off nuclear targets can provide guidance on ${\mathrm{q̂}}_h$ in the hot hadronic matter. One can then study the dependence of the extracted initial value of jet-quenching parameter ${\mathrm{q̂}}_0$ at initial time ${\tau }_0$ on the bulk medium evolution. Effects of transverse expansion, radial flow, phase transition, and nonequilibrium evolution are examined. The extracted values are found to vary from ${\mathrm{q̂}}_0{\tau }_0=0.54$ GeV${}^2$ in the ($1+3$)d ideal hydrodynamic model to 0.96 GeV${}^2$ in a cascade model, with the main differences coming from the initial nonequilibrium evolution and the later hadronic evolution. The overall contribution to jet quenching from the hadronic phase, about $22\%–44$$\%$, is found to be significant. Therefore, a realistic description of the early nonequilibrium parton evolution and later hadronic interaction will be critical for accurate extraction of the jet transport parameter in the strongly interacting QGP phase in high-energy heavy-ion collisions.

We develop a chiral SU($3$) symmetric relativistic mean field model with a logarithmic potential of scalar condensates. Experimental and empirical data of symmetric nuclear matter saturation properties, bulk properties of normal nuclei, and separation energies of single- and double-$\Lambda$ hypernuclei are well explained. The nuclear matter equation of state (EOS) is found to be softened by $\sigma \zeta$ mixing which comes from determinant interaction. The neutron star matter EOS is further softened by $\Lambda$ hyperons.

We show that two $P_{11}$ nucleon resonance poles near the $\pi \Delta$ threshold, obtained in several analyses, are stable against large variations of parameters within a dynamical coupled-channels analysis based on meson-exchange mechanisms. By also performing an analysis based on a model with a bare nucleon state, we find that this two-pole structure is insensitive to the analytic structure of the amplitude in the region below the $\pi N$ threshold. Our results are $M_{\mathrm{pole}}=({1363}_{-6}^{+9}-i{79}_{-5}^{+3})$ and $({1373}_{-10}^{+12}-i{114}_{-9}^{+14})$ MeV. We also demonstrate that the number of poles in the 1.5-GeV $⩽W⩽$ 2-GeV region could be more than one, depending on how the structure of the single-energy solution of SAID is fitted. For three-pole solutions, our best estimated result of a pole near $N(1710)$ listed by Particle Data Group is $({1829}_{-65}^{+131}-i{192}_{-110}^{+88})$ MeV, which is close to the results of several previous analyses. Our results indicate the need for more accurate $\pi N$ reaction data in the $W>$ 1.6-GeV region for high-precision resonance extractions.

Excited states of ${}_{56}^{135}{\mathrm{Ba}}_{79}$ at high spins are studied using the reaction ${}^{130}\mathrm{Te}$(${}^9\mathrm{Be}$,$4n$)${}_{56}^{135}{\mathrm{Ba}}_{79}$ at $42.5$-MeV beam energy. The earlier known level scheme is extended up to $6.4$-MeV excitation energy and ($37/2$)$\hslash$ spin with the addition of several transitions. We have performed polarization asymmetry measurements for some of the strong transitions by using a Clover detector to assign the parity. A comparison of experimental data with the results of tilted axis cranking calculations based on various configurations indicates the coexistence of multiple minima in the triaxial deformation ($\gamma$), whereas axial symmetric deformation (${\epsilon }_2$) remains constant around $0.09$.

A simple formula is derived that describes how the Coulomb interaction affects the proton radius in nuclei. It determines the difference between neutron and proton radii in nuclei with $N\approx Z$. It also estimates the difference between the radii of the $Z$ core neutrons and protons in nuclei with a large neutron excess. The results obtained from the derived formula are compared with radii calculated in a Skyrme Hartree-Fock calculation.

A new measurement of subthreshold $K^{*}(892){}^0$ and $K^0$ production is presented. The experimental data complete the measurement of strange particles produced in $\mathrm{Al}+\mathrm{Al}$ collisions at 1.9$A$ GeV measured with the FOPI detector at SIS at GSI (Darmstadt). The $K^{*}(892){}^0/K^0$ yield ratio is found to be $0.0315\pm 0.006(\mathrm{stat}.)\pm 0.012(\mathrm{syst}.)$ and is in good agreement with the transport model prediction. These measurements provide information on the in-medium cross section of $K^{+}$-${\pi }^{-}$ fusion, which is the dominant process in subthreshold $K^{*}(892){}^0$ production.