The neutron capture cross section of ${}^{204}\mathrm{Pb}$ has been measured at the CERN n_TOF installation with high resolution in the energy range from 1 eV to 440 keV. An R-matrix analysis of the resolved resonance region, between 1 eV and 100 keV, was carried out using the SAMMY code. In the interval between 100 keV and 440 keV we report the average capture cross section. The background in the entire neutron energy range was reliably determined from the measurement of a ${}^{208}\mathrm{Pb}$ sample. Other systematic effects in this measurement were investigated and precisely corrected by means of detailed Monte Carlo simulations. We obtain a Maxwellian average capture cross section for ${}^{204}\mathrm{Pb}$ at $\mathit{kT}=30$ keV of 79(3) mb, in agreement with previous experiments. However our cross section at $\mathit{kT}=5$ keV is about 35% larger than the values reported so far. The implications of the new cross section for the $s$-process abundance contributions in the Pb/Bi region are discussed.

Measurements of η meson production in proton-deuteron collisions have been performed using the COSY-11 facility at COSY (Jülich). Results on total and differential cross sections for the $\mathit{pd}\to$${}^3\mathrm{He}$$\eta$ reaction are presented at five excess energies between $Q=5.0$ and $Q=40.6$ MeV. The angular distributions show a transition from an almost isotropic emission close to threshold to a highly anisotropic distribution at higher excess energies. The total cross sections reveal a strong $\eta \text{−}$${}^3\mathrm{He}$ final state interaction, corresponding to a scattering length of $|\Re (a)|=(4.2\pm 0.5)$ fm and $\Im (a)=(0.4\pm 1.9)$ fm.

We examine to what extent correlated realistic nucleon-nucleon interactions, derived within the unitary correlation operator method (UCOM), can describe nuclear collective motion in the framework of first-order random-phase approximation (RPA). To this end we employ the correlated Argonne V18 interaction in calculations within the so-called “Extended” RPA (ERPA) and investigate the response of closed-shell nuclei. The ERPA is a renormalized RPA version which considers explicitly the depletion of the Fermi sea due to long-range correlations and thus allows us to examine how these affect the excitation spectra. It is found that the effect on the properties of giant resonances is rather small. Compared to the standard RPA, where excitations are built on top of the uncorrelated Hartree-Fock (HF) ground state, their centroid energies decrease by up to 1 MeV, approximately, in the isovector channel. The isoscalar response is less affected in general. Thus, the disagreement between our previous UCOM-based RPA calculations and the experimental data are to be attributed to other effects, namely to residual three-body terms in the Hamiltonian and to higher-order configurations. Single-particle energies and occupation probabilities obtained within the ERPA are compared with corresponding HF and perturbation-theory results and are discussed as well. The ERPA formalism is presented in detail.

Decay by proton emission from high-lying states in ${}^{91}\mathrm{Nb}$, populated in the ${}^{90}\mathrm{Zr}$$(\alpha ,t)$ reaction at $E_{\alpha }=180$ MeV, has been investigated. Decay to the ground state and semidirect decay to the low-lying ($2^{+},5^{-}$, and $3^{-}$) phonon states in ${}^{90}\mathrm{Zr}$ were observed. It was found that these phonon states play an important role in the damping process of the single-particle states. An optical-model coupled-channel approach was used successfully to describe the direct and semidirect parts of the decay.

The effect of fluctuations of strong color electric fields (SCF) on the baryon production in $d+\mathrm{Au}$ and Au+Au collisions at $200A$ GeV is studied in the framework of the HIJING/B$\overline{B}$ v2.0 model. It is shown that the dynamics of the production process deviates considerably from calculations based on Schwinger-like estimates for homogeneous and constant color fields. An increase of the string tension from ${\kappa }_0=1$ GeV/fm, to in medium mean values of 1.5 to 2.0 GeV/fm and 2.0 to 3.0 GeV/fm for $d+\mathrm{Au}$ and Au+Au, respectively, results in a consistent description of the observed nuclear modification factors $R_{d\mathrm{Au}}$ and $R_{\mathrm{AuAu}}$ [that relates ($d$)Au+Au and $p+p$ collisions], and point to the relevance of fluctuations of transient color fields. The differences between nuclear modification factors $R_{\mathrm{AuAu}}$ and $R_{\mathrm{CP}}$ (that relates central and peripheral collisions) are also discussed. The measurement of multistrange (anti)hyperons $(\Xi ,\Omega )$ yields would provide a crucial test of the importance of SCF fluctuations at RHIC energies.

Within the dynamical model of Refs. [Phys. Rev. C 54, 2660 (1996); 63, 055201 (2001)], we perform an analysis of recent data of pion electroproduction reactions at energies near the $\Delta (1232)$ resonance. We discuss possible interpretations of the extracted bare and dressed $\gamma N\to \Delta$ form factors in terms of relativistic constituent quark models and lattice quantum chromodynamics calculations. Possible future developments are discussed.

A comprehensive analysis of electrodisintegration yields of protons on ${}^{90}\mathrm{Zr}$ is proposed taking into account the giant dipole resonance, isovector giant quadrupole resonance (IVGQR), and quasideuteron contributions to the total photoabsorption cross section from 10 to 140 MeV. The calculation applies the MCMC intranuclear cascade to address the direct and pre-equilibrium emissions and another Monte Carlo-based algorithm to describe the evaporation step. The final results of the total photoabsorption cross section for ${}^{90}\mathrm{Zr}$ and relevant decay channels are obtained by fitting the $(e,p)$ measurements from the National Bureau of Standards and show that multiple proton emissions dominate the photonuclear reactions at higher energies. These results provide a consistent explanation for the exotic and steady increase of the $(e,p)$ yield and also a strong evidence of a IVGQR with a strength parameter compatible with the $E2$ energy-weighted sum rule. The inclusive photoneutron cross sections for ${}^{90}\mathrm{Zr}$ and ${}^{\mathrm{nat}}$Zr, derived from these results and normalized with the $(e,p)$ data, are in agreement within 10% with both Livermore and Saclay data up to 140 MeV.

Two-kaon production in proton-deuteron collisions has been studied at three energies close to threshold using a calibrated magnetic spectrograph to measure the final ${}^3\mathrm{He}$ and a vertex detector to measure the $K^{+}{K}^{-}$ pair. Differential and total cross sections are presented for the production of ϕ-mesons, decaying through $\varphi \to K^{+}{K}^{-}$, as well as for prompt $K^{+}{K}^{-}$ production. The prompt production seems to follow phase space in both its differential distributions and in its energy dependence. The amplitude for the $\mathit{pd}\to {}^3\mathrm{He}\varphi$ reaction varies little for excess energies below 22 MeV and the value is consistent with that obtained from a threshold measurement. The angular distribution of the $K^{+}{K}^{-}$ decay pair shows that near threshold the ϕ-mesons are dominantly produced with polarization $m=0$ along the initial proton direction. No conclusive evidence for $f_0(980)$ production is found in the data.

The asymmetry dependence of the caloric curve, for mononuclear configurations, is studied as a function of neutron-to-proton asymmetry with a model that allows for independent variation of the neutron and proton surface diffusenesses. The evolution of the effective mass with density and excitation is included in a schematic fashion and the entropies are extracted in a local density approximation. The plateau in the caloric curve displays only a slight sensitivity to the asymmetry.

Elastic scattering of the weakly bound ${}^6\mathrm{Li}$ on ${}^{27}\mathrm{Al}$ was measured at near-barrier energies. The data analysis was performed using a Woods-Saxon shape optical potential and also using the double-folding São Paulo potential. The results show the presence of the breakup threshold anomaly (BTA), an anomalous behavior when compared with the scattering of tightly bound nuclei. This behavior is attributed to a repulsive polarization potential produced by the coupling to the continuum breakup states.

Benchmark calculations are performed aiming to test the use of two different pseudostate bases on the multiple scattering expansion of the total transition amplitude scattering framework. Calculated differential cross sections for $p\text{−}$${}^6\mathrm{He}$ inelastic scattering at 717 MeV/nucleon show a good agreement between the observables calculated in the two bases. This result gives extra confidence on the pseudostate representation of continuum states to describe inelastic/breakup scattering.

The Doppler Shift Attenuation Method was used to measure lifetimes for levels in ${}^{38}\mathrm{K}$ at excitation energies of 1698, 2404, 2830, 2996, and 3671 keV, populated using the ${}^{40}\mathrm{Ca}$(d, α)${}^{38}\mathrm{K}$ reaction at a beam energy of 4.5 MeV. Values of 109(29), 95(22), 457(63), 130(40), and 160(50) fs, respectively, were measured and are compared with previous values obtained using different stopping powers. The matrix element for the transition between the $J^{\pi }=2_{T=1}^{+}$ and $0_{T=1}^{+}$ states in this $T_z=0$ nucleus is compared with the analogous transition in the other nuclei in the $T=1$ triplet, ${}^{38}\mathrm{Ca}$ ($T_z=-1$) and ${}^{38}\mathrm{Ar}$ ($T_z=+1$), and with the results of shell-model calculations.

The sizes, temperatures, and free neutron-to-proton ratios of the initial interaction zones produced in the collisions of 40 MeV/nucleon ${}^{40}\mathrm{Ar}$+${}^{112}\mathrm{Sn}$ and 55 MeV/nucleon ${}^{27}\mathrm{Al}$+${}^{124}\mathrm{Sn}$ are derived using total detected neutron plus charged particle multiplicity as a measure of the impact parameter range and number of participant nucleons. The size of the initial interaction zone, determined from a coalescence model analysis, increases significantly with decreasing impact parameter. The temperatures and free neutron-to-proton ratios in the interaction zones are relatively similar for different impact parameter ranges and evolve in a similar fashion.

The breaking of chiral symmetry of light quarks at zero temperature in the presence of strong quantizing magnetic field is studied using a Nambu-Jona-Lasinio (NJL) model with a Thomas-Fermi-type semiclassical formalism. It is found that the dynamically generated light quark mass can never become zero if the Landau levels are populated and increases with the increase of magnetic field strength.

Neutron rich Zr nuclei with number of neutrons between $N=50$ and 82 are investigated in the relativistic mean field approach in coordinate space. The resonant levels in the positive energy continuum have been explicitly included in the calculation. Odd nuclei have been treated in the blocking approximation. Our calculation indicates that the dripline for odd mass isotopes is far away from that for the even mass ones. Pairing interaction plays a significant role in stabilizing the even isotopes, thus extending the dripline for them.

The β-decay of ${}^{32}\mathrm{Na}$ has been studied using $\beta \text{−}\gamma$ coincidences. New transitions and levels are tentatively placed in the level scheme of ${}^{32}\mathrm{Mg}$ from an analysis of $\gamma \text{−}\gamma$ and $\beta \text{−}\gamma \text{−}\gamma$ coincidences. The observation of the indirect feeding of the 2321 keV state in ${}^{32}\mathrm{Mg}$ removes some restrictions previously placed on the spin assignment for this state. No evidence of a state at 2117 keV in ${}^{32}\mathrm{Mg}$ is found. Previously unobserved weak transitions up to 5.4 MeV were recorded but could not be placed in the decay scheme of ${}^{32}\mathrm{Na}$.

The β-delayed α-spectrum of ${}^{18}\mathrm{N}$ has been measured at the TISOL facility at TRIUMF resolving the structure of a broad α-particle distribution at α-energies of 1.5–5.5 MeV into several states that show a distinct interference pattern. $R$-matrix fits assuming a solely $J^{\pi }=1^{-}$ partial wave confirm this finding. The extrapolated low energy part of this structure constitutes the natural parity background in a possible experiment to observe the parity forbidden α-decay of the $E_x=6.880$ MeV, $J^{\pi }=0^{-}$ state in ${}^{18}\mathrm{O}$ that is estimated from the fit to be $2\times {10}^{-8}$ of the intensity of the $E_{\alpha }=1081$ keV peak. In addition, the tails of the broad $1^{-}$ states observed likely contribute to the astrophysical ${}^{14}\mathrm{C}$ ($\alpha ,\gamma$)${}^{18}\mathrm{O}$ reaction rate though the experimental information available is too incomplete to allow precise predictions. The β-delayed α-spectrum of ${}^{18}\mathrm{N}$ also excludes complex β-feeding amplitudes at a significant level. The states seen in the β-delayed α-decay produce a pattern of approximately equally spaced $1^{-}$ states in ${}^{18}\mathrm{O}$ consistent with $J^{\pi }=1^{-}$ states seen at the same and higher excitation energies of ${}^{18}\mathrm{O}$.

The self-consistent mean-field quantum mechanical solution of a vortex and a nucleus immersed in a sea of free neutrons, a scenario representative of the inner crust of neutron stars, is presented for the first time. Because of quantal size effects the phase space for vortices inside the nucleus is essentially zero, so that the vortex core opens up and surrounds the nucleus. As a consequence, pinned configurations (in which a vortex becomes anchored to the nucleus) are favored at low and high densities in the inner crust. This result is qualitatively different from that obtained in all previous models, which predict pinning at intermediate densities.

In very well-defined parts of the phase space, $KN$ and $\Lambda N$ rescattering depend on on-shell elementary matrix elements and on the low momentum components of the deuteron wave function. This provides us with the unique opportunity to study details in the scattering amplitudes that may have escaped the analysis of reactions induced on a nucleon target by kaon and hyperon beams at low energies. When folded with a typical experimental mass resolution, a narrow state with a width of 1 MeV would contribute by no more than 10% to the $\mathit{KN}$ mass spectrum. On the contrary, a cusp would be easily detected near the Σ production threshold in the $\Lambda N$ mass spectrum.

The tensor electric polarizability of the deuteron gives important information about spin-dependent nuclear forces. If a resonant horizontal electric field acts on a deuteron beam circulating into a storage ring, the tensor electric polarizability stimulates the buildup of the vertical polarization of the deuteron (the Baryshevsky effect). General formulas describing this effect have been derived. Calculated formulas agree with the earlier obtained results. The problem of the influence of tensor electric polarizability on spin dynamics in such a deuteron electric-dipole-moment experiment in storage rings has been investigated. Doubling the resonant frequency used in this experiment dramatically amplifies the Baryshevsky effect and provides the opportunity to make high-precision measurements of the deuteron's tensor electric polarizability.