The ${}^{64}\mathrm{Ni}$($d$,${}^2\mathrm{He}$)${}^{64}\mathrm{Co}$ reaction was studied at the AGOR cyclotron of KVI, Groningen, with the Big-Bite Spectrometer and the EuroSuperNova detector using a 171-MeV deuteron beam. An energy resolution of about 110 keV was achieved. In addition to the $J{}^{\pi }$ = $1^{+}$ ground state, several other $1^{+}$ states could be identified in ${}^{64}\mathrm{Co}$ and the strengths of the corresponding Gamow-Teller transitions were determined. The obtained strength distribution was compared with theoretical predictions and former $(n,p)$ experimental results and displayed a good agreement. Due to the good energy resolution, detailed spectroscopic information was obtained, which supplements the data base needed for network calculations for supernova scenarios.

We have studied charged nuclear fragments produced by 200- to 400-MeV/nucleon carbon ions, interacting with water and polycarbonate, using a newly developed emulsion detector. Total and partial charge-changing cross sections for the production of B, Be, and Li fragments were measured and compared with both previously published measurements and model predictions. This study is of importance for validating and improving carbon-ion therapy treatment planning systems and for estimating the radiological risks for personnel on space missions, because carbon is a significant component of galactic cosmic rays.

Indirect methods play an important role in the determination of nuclear reaction cross sections that are hard to measure directly. In this paper we investigate the feasibility of using the so-called surrogate method to extract neutron capture cross sections for low-energy compound-nuclear reactions in spherical and near-spherical nuclei. We present the surrogate method and develop a statistical nuclear reaction simulation to explore different approaches to utilizing surrogate reaction data. We assess the success of each approach by comparing the extracted cross sections with a predetermined benchmark. In particular, we employ regional systematics of nuclear properties in the $34⩽Z⩽46$ region to calculate $(n,\gamma )$ cross sections for a series of Zr isotopes and to simulate a surrogate experiment and the extraction of the desired cross section. We identify one particular approach that may provide very useful estimates of the cross section, and we discuss some of the limitations of the method. General recommendations for future (surrogate) experiments are also given.

We aim to carry out the detailed study of system-size effects and momentum correlations by simulating the reactions of ${}^{12}\mathrm{C}$+${}^{12}\mathrm{C}$, ${}^{20}\mathrm{Ne}$+${}^{20}\mathrm{Ne}$, ${}^{40}\mathrm{Ca}$+${}^{40}\mathrm{Ca}$, ${}^{58}\mathrm{Ni}$+${}^{58}\mathrm{Ni}$,${}^{93}\mathrm{Nb}$+${}^{93}\mathrm{Nb}$, ${}^{129}\mathrm{Xe}$+${}^{118}\mathrm{Sn}$, ${}^{139}\mathrm{La}$+${}^{139}\mathrm{La}$, and ${}^{197}\mathrm{Au}$+${}^{197}\mathrm{Au}$ at an incident energy of 400 MeV/nucleon and over entire colliding geometry from a central to an extreme peripheral one. A mass-independent role of the momentum correlations is reported for the entire periodic table. When averaged over all fragments, the effect of momentum correlations for central collisions is about 39%. All mass yields can be parametrized by a power law with $2⩽\tau ⩽3$ which is in agreement with other theoretical and experimental studies.

We study the cluster-shell competition in carbon isotopes. Two parameters are introduced for the ${}^{12}\mathrm{C}$ core to characterize the transition from a cluster state to a shell-model state as a measure of the cluster-shell competition: one expresses the relative distance between α clusters and the other does the dissolution of one of the α clusters. We show the energy curves as functions of these parameters. The calculation is performed by combining the simplified modeling of cluster-shell competition for the ${}^{12}\mathrm{C}$ core and AMD triple-S. As the neutron number increases, the $\alpha \text{−}\alpha$ distance becomes smaller; on the contrary, the dissolution of α clusters is enhanced. The origins of the anomalously small $B(E2)$ value of ${}^{16}\mathrm{C}$ are discussed from cluster-shell competition point of view, and the appearance of pure cluster state around the 10 MeV region is suggested.

Lifetimes of levels below 4 MeV in ${}^{112}\mathrm{Cd}$ have been measured using the Doppler shift attenuation technique following inelastic scattering of monoenergetic neutrons. Reduced transition rates are determined using the results of previous studies and the current lifetimes. The electromagnetic properties of ${}^{112}\mathrm{Cd}$ are outlined, and together with results from previous nucleon-transfer studies and inelastic scattering, the levels in ${}^{112}\mathrm{Cd}$ are interpreted in terms of single-particle configurations and collective excitations, assuming a vibrational model with intruder states. The collective states and their γ-ray decays are compared with IBM-2 model calculations that allow for the mixing between the normal phonon states and intruder configurations. Levels below 1.5 MeV are reproduced reasonably well, whereas at higher excitation energy the calculations fail to reproduce the data in detail.

Lifetimes of low-lying states in ${}^{102,104}\mathrm{Cd}$ were determined by using the recoil distance Doppler-shift technique with a plunger device and a Ge array consisting of five HP Ge detectors and one Euroball cluster detector. The experiments were carried out at the Cologne FN Tandem facility using the ${}^{92}\mathrm{Mo}$(${}^{12}\mathrm{C}$,$2n$)${}^{102}\mathrm{Cd}$ reaction at 41 MeV and the ${}^{94}\mathrm{Mo}$(${}^{12}\mathrm{C}$,$2n$)${}^{104}\mathrm{Cd}$ reaction at 42 MeV. The differential decay curve method in coincidence mode was employed to derive the lifetime of the first $2^{+}$ state in both nuclei and the lifetime of the $4^{+}$ state in ${}^{104}\mathrm{Cd}$. The corresponding reduced $E2$ transition probabilities have been studied within the framework of the nuclear shell model.

The influence on fusion of coupling to the breakup process is investigated for reactions where at least one of the colliding nuclei has a sufficiently low binding energy for breakup to become an important process. Elastic scattering, excitation functions for sub- and near-barrier fusion cross sections, and breakup yields are analyzed for ${}^{6,7}\mathrm{Li}+{}^{59}\mathrm{Co}$. Continuum-discretized coupled-channels (CDCC) calculations describe well the data at and above the barrier. Elastic scattering with ${}^6\mathrm{Li}$ (as compared to ${}^7\mathrm{Li}$) indicates the significant role of breakup for weakly bound projectiles. A study of ${}^{4,6}\mathrm{He}$ induced fusion reactions with a three-body CDCC method for the ${}^6\mathrm{He}$ halo nucleus is presented. The relative importance of breakup and bound-state structure effects on total fusion is discussed.

We investigate the $\mathit{pp}\to \mathit{pp}\eta$ and $\mathit{pn}\to \mathit{pn}\eta$ reactions within an effective Lagrangian model for laboratory kinetic energies ranging from very close to the η-meson production threshold to about 10 GeV. Production amplitudes include contributions from the mechanisms of excitation, propagation, and decay of $N^{*}(1535),N^{*}(1650)$, and $N^{*}(1710)$ baryonic resonances. The initial interaction between two incoming nucleons is modeled by the exchange of $\pi ,\rho ,\omega ,$ and σ mesons where the vertex parameters are taken to be the same as those used in the previous applications of this model. Parameters of the resonance vertices also are taken from our earlier studies wherever applicable. Calculations are done for total as well as differential η-production cross sections. To describe the data for energies closer to the production threshold, final state interactions among the outgoing particles are included by means of a generalized Watson-Migdal method. Terms corresponding to the excitation of $N^{*}$(1535) resonance and the pion exchange process dominate the cross sections. With a single set of vertex parameters, our model describes well the available data on total cross sections for beam energies ranging from close to threshold to up to 10 GeV.

In the present work, we investigate the main differences in the lead neutron skin thickness, binding energy, surface energy, and density profiles obtained with two different density dependent hadron models. Our results are calculated within the Thomas-Fermi approximation with two different numerical prescriptions and compared with results obtained with a common parametrization of the nonlinear Walecka model. The neutron skin thickness is a reflex of the equation of state properties. Hence, a direct correlation is found between the neutron skin thickness and the slope of the symmetry energy. We show that within the present approximations, the asymmetry parameter for low momentum transfer polarized electron scattering is not sensitive to the model differences.

Since the seminal work of Negele and Vautherin, the Wigner-Seitz approximation has been widely applied to study the inner crust of neutron stars formed of nuclear clusters immersed in a neutron sea. In this article, the validity of this approximation is discussed in the framework of the band theory of solids. For a typical cell of ${}^{200}\mathrm{Zr}$, present in the external layers of the inner crust, it is shown that the ground state properties of the neutron gas are rather well reproduced by the Wigner-Seitz approximation, while its dynamical properties depend on the energy scale of the process of interest or on the temperature. It is concluded that the Wigner-Seitz approximation is well suited for describing the inner crust of young neutron stars and the collapsing core of massive stars during supernovae explosions. However, the band theory is required for low temperature transport properties as, for instance, the effective neutron mass giving rise to entrainment effects.

New experimental total β-decay energies of ${}^{135,136}\mathrm{Te}$ and of the two isomers of ${}^{136}\mathrm{I}$ have been obtained, giving much improved accuracy for the nuclear masses of these nuclides. The neutron separation energies at $N=83$ were deduced and are compared to recent theoretical and systematic predictions. The new results resolve the problem with the excitation energy of the isomeric state of ${}^{136}\mathrm{I}$. Theoretical calculations of the isomer splitting of ${}^{136}\mathrm{I}$ are in good agreement with the new data.

The systematic dependence of fusion barrier energies on neutron excess can be determined over a broader range using radioactive nuclei. It is shown that precise measurements with a wide range of stable isotopes are necessary for optimum interpretation of radioactive beam measurements. New precision cross-section data for fusion of ${}^{32,34,36}\mathrm{S}$ projectiles with Pb isotopes are presented, aiding in a revised interpretation of recent ${}^{38}\mathrm{S}$ fusion data, which now appears more likely to follow the same trend as the stable isotopes than to show the unexpected behavior previously inferred.

The ${}^{12}\mathrm{C}$(${}^{12}\mathrm{C}$,${}^{14}\mathrm{O}$) two-proton pick-up reaction has been measured at 211.4 MeV incident energy to study the structure of states of ${}^{10}\mathrm{Be}$ up to excitation energies of 12 MeV. The measured partial angular distributions show pronounced oscillatory shapes, which were described by coupled-reaction-channels calculations. Spin-parity assignments could be derived from these characteristic shapes and two definite assignments have been made. The state at 11.8 MeV has been identified as the 4${}^{+}$ member of the ground-state band, and the state at 10.55 MeV is assigned $J^{\pi }=3^{-}$. At 5.96 MeV only the $1_1^{-}$ member of the known $2_2^{+}/1_1^{-}$ doublet is populated. The angular distribution of the peak at 9.50 MeV, which consists of several unresolved states, has been unfolded using contributions from known states at 9.56 MeV, $2^{+}$, and 9.27 MeV, $4^{-}$. The inclusion of a state at 9.4 MeV reported by Daito et al. from the ${}^{10}\mathrm{B}$($t,{}^3\mathrm{He}$)${}^{10}\mathrm{Be}$ reaction and tentatively assigned ($3^{+}$) improved the fit considerably. A K$=2$ band is formed with the $2_2^{+}$ state as the band head and the ($3^{+}$) state as the second member. The structures of the $K^{\pi }=0^{+}{}_1,2{}^{+}{}_2$, and $1_1^{-}$ bands are discussed.

The recombination model is applied to the production of $K,\varphi ,\Lambda$ , and Ω at all $p_T$ in central Au+Au collisions. The thermal-shower component of the recombination is found to be important for $K$ and Λ, but only in a minor way for ϕ and Ω in the intermediate to high $p_T$ region. The normalization and inverse slope of the thermal partons in the strange sector are determined by fitting the low-$p_T$ data. At higher $p_T$ the data of $K,\Lambda ,\varphi$, and Ω in the log scale are all well reproduced in our study that extends the thermal contribution and includes the shower contribution. The calculated result on the $\Lambda /K$ ratio rises to a maximum of around 2 at $p_T\approx 4$ GeV/$c$, arching over the data in linear scale. The production of ϕ and Ω are shown to arise mainly from the recombination of thermal partons, thus exhibiting exponential $p_T$ dependences in agreement with the data. Their ratio, $R_{\Omega /\varphi }$, rises linearly to $p_T\approx 4$ GeV/$c$ and develops a maximum at $p_T\approx 5.5$ GeV/$c$. It is argued that the $p_T$ spectra of ϕ and Ω reveal directly the partonic nature of the thermal source that characterizes quark-gluon plasma. Comments are made on the Ω puzzle due to the simultaneous observation of both the exponential behavior of the Ω spectrum in $p_T$ and the existence of low-$p_T$ particles associated with Ω as trigger.

We extend the virial equation of state to include ${}^3\mathrm{H}$ and ${}^3\mathrm{He}$ nuclei, and predict significant mass-three fractions near the neutrinosphere in supernovae. While alpha particles are often more abundant, we demonstrate that energy transfer cross sections for muon and tau neutrinos at low densities are dominated by breakup of the loosely-bound ${}^3\mathrm{H}$ and ${}^3\mathrm{He}$ nuclei. The virial coefficients involving $A=3$ nuclei are calculated directly from the corresponding nucleon-${}^3\mathrm{H}$ and nucleon-${}^3\mathrm{He}$ scattering phase shifts. For the neutral-current inelastic cross sections and the energy transfer cross sections, we perform ab initio calculations based on microscopic two- and three-nucleon interactions and meson-exchange currents.

We use the modified quark-meson coupling (MQMC) model to study the composition profile of neutron star matter and compare the results with those calculated by quantum hadrodynamics (QHD). Both MQMC and QHD model parameters are adjusted to produce exactly the same saturation properties so that we can investigate the model dependences of the matter composition at high densities. We consider the possibility of deep kaon optical potential and find that the composition of matter is very sensitive to the interaction strength of kaons with matter. The onset densities of the kaon condensation are studied in detail by varying the kaon optical potentials. We find that the MQMC model produces the kaon condensation at lower densities than QHD. The presence of kaon condensation changes drastically the population of octet baryons and leptons. Once the kaon condensation takes place, the population of kaons builds up very quickly, and kaons become the dominant component of the matter. We find that the ω meson plays an important role in increasing the kaon population and suppressing the hyperon population.

Quark and gluon jets traversing through a quark-gluon plasma not only lose their energies but also can undergo flavor conversions. The conversion rates via the elastic $q(\overline{q})g\to \mathit{gq}(\overline{q})$ and the inelastic $q\overline{q}\leftrightarrow \mathit{gg}$ scatterings are evaluated in the lowest order in QCD. Including both jet energy loss and conversions in the expanding quark-gluon plasma produced in relativistic heavy ion collisions, we have found a net of quark jets to gluon jets. This reduces the difference between the nuclear modification factors for quark and gluon jets in central heavy ion collisions and thus enhances the $p/{\pi }^{+}$ and $\overline{p}/{\pi }^{-}$ ratios at high transverse momentum. However, a much larger net quark-to-gluon jet conversion rate than the one given by the lowest order QCD is needed to account for the observed similar ratios in central Au+Au and $p+p$ collisions at the same energy. Implications of our results are discussed.

An experimental study of the lower $\mathit{fp}$-shell nuclei ${}^{42,43}\mathrm{Sc}$ was performed via $\alpha \mathit{pn}$ and $\alpha p$ evaporation, respectively, from ${}^{20}\mathrm{Ne}$ + ${}^{28}\mathrm{Si}$ and ${}^{24}\mathrm{Mg}$ + ${}^{24}\mathrm{Mg}$ fusion-evaporation reactions. The experiments were conducted with the Gammasphere and Microball detector arrays. The level schemes of both nuclei have been extended considerably. Terminating states associated with the $f_{7/2}{}^n$ and $d_{3/2}{}^{-1}{f}_{7/2}{}^{n+1}$ configurations were identified in each nuclide and incorporated into detailed comparisons with neighboring nuclei and with shell model calculations. The energy differences between the terminating states provide a test of the $\mathit{sd}\text{−}\mathit{fp}$ cross-shell interactions in these calculations.