The extrapolations of cross sections for fusion reactions involving ${}^{12}\mathrm{C}$ and ${}^{16}\mathrm{O}$ nuclei down to energies relevant for explosive stellar burning have been reexamined. Based on a systematic study of fusion in heavier systems, it is expected that a suppression of the fusion process will also be present in these light heavy-ion systems at extreme sub-barrier energies due to the saturation properties of nuclear matter. Previous phenomenological extrapolations of the $S$ factor for light heavy-ion fusion based on optical model calculations may therefore have overestimated the corresponding reaction rates. A new “recipe” is proposed to extrapolate $S$ factors for light heavy-ion reactions to low energies taking the hindrance behavior into account. It is based on a fit to the logarithmic derivative of the experimental cross section which is much less sensitive to overall normalization discrepancies between different data sets than other approaches. This method, therefore, represents a significant improvement over other extrapolations. The impact on the astrophysical reaction rates is discussed.

The stellar neutron capture cross sections of ${}^{174}\mathrm{Hf}$ and the radioactive isotope ${}^{182}\mathrm{Hf}$ ($t_{1/2}=8.9\times {10}^6$ yr) have been measured for the first time at $\mathit{kT}=25$ keV by means of the activation technique. These isotopes originate from different stellar scenarios, ${}^{174}\mathrm{Hf}$ from the $p$-process by a series of photodisintegration reactions of heavier seed nuclei, and ${}^{182}\mathrm{Hf}$ from the $s$-process in asymptotic giant branch stars as well as from the $r$-process in supernovae or neutron star mergers. Both activation measurements were carried out at the Karlsruhe Van de Graaff accelerator using the ${}^7\mathrm{Li}$($p,n$)${}^7\mathrm{Be}$ reaction for simulating a Maxwellian neutron spectrum corresponding to a thermal energy of $\mathit{kT}=25$ keV. The Maxwellian averaged cross sections (MACS) extrapolated to the common $s$-process temperatures at $\mathit{kT}=30$ keV yield $\langle \sigma \rangle {}_{30}=983\pm 46$ and $141\pm 8$ mb for ${}^{174}\mathrm{Hf}$ and ${}^{182}\mathrm{Hf}$, respectively.

The deuteron tensor polarization component $T_{20}(Q^2)$ is calculated by the relativistic Hamiltonian dynamics approach. It is shown that in the range of momentum transfers available with current experiments, relativistic effects, meson exchange currents, and the choice of nucleon electromagnetic form factors almost do not influence the value of $T_{20}(Q^2)$. However, this value depends strongly on the actual form of the deuteron wave function, that is, on the model of the $\mathit{NN}$ interaction in the deuteron. So the existing data for $T_{20}(Q^2)$ provide a crucial test for deuteron wave functions.

The Gammasphere spectrometer, in conjunction with the Microball charged-particle array, was used to investigate high-spin states in ${}^{112}\mathrm{Te}$ via ${}^{58}\mathrm{Ni}$(${}^{58}\mathrm{Ni}$, $4p\gamma$) reactions at 240 and 250 MeV. Several smooth terminating bands were established, and lifetime measurements were performed for the strongest one using the Doppler-shift attenuation method. Results obtained in the spin range $18\text{−}32\hslash$ yield a transition quadrupole moment of $4.0\pm 0.5\mathit{eb}$, which corresponds to a quadrupole deformation ${\varepsilon }_2=0.26\pm 0.03$; this value is significantly larger than the ground-state deformation of tellurium isotopes. It was also possible to extract a transition quadrupole moment for the yrast band in ${}^{114}\mathrm{Xe}$, produced via the $58$Ni ($58$Ni, $2p\gamma$) reaction. A value of $3.0\pm 0.5\mathit{eb}$ was found in the spin range $16\text{−}24\hslash$, which corresponds to a quadrupole deformation ${\varepsilon }_2=0.19\pm 0.03$. Cranked Nilsson-Strutinsky calculations are used to interpret the results.

Three possible scenarios of the statistical hadronization model are reexamined with the use of the $p_T$ spectra of the PHENIX and very low $p_T$ PHOBOS measurements at $\sqrt{s_{NN}}=200$ GeV. These scenarios are as follows: (a) full chemical nonequilibrium, (b) strangeness chemical nonequilibrium, and (c) chemical equilibrium. Fits to the spectra are done within the Cracow single-freeze-out model, which takes into account both the expansion and resonance decays. Predictions for spectra of $\varphi ,K(892){}^{*0}$, and ${\pi }^0$ are also given. Global variables such as the transverse energy at midrapidity, the charged particle multiplicity at midrapidity, and the total multiplicity of charged particles are evaluated and their predicted values agree qualitatively well with the experimental data. The thorough analysis within this model suggests that the chemical full nonequilibrium case is the least likely and both other cases are of similar likelihood. It is also shown that if the full chemical nonequilibrium freeze-out took place it could manifest itself in the enhancement of the ${\pi }^0$ production at very low transverse momenta.

It is shown that in an inhomogeneous neutron matter the pairing field bounds neutrons around the Fermi level leading to the formation of localized Andreev states. In the case of the inner crust of neutron stars the localization length is determined as a function of nuclear density.

Excited states in ${}^{46}\mathrm{Cr}$ were sought using the ${}^{12}\mathrm{C}$(${}^{36}\mathrm{Ar}$,$2n$) reaction. Gamma rays were detected with the Gammasphere array, and the $Z$ value of the reaction products was determined with an ionization chamber located at the focal plane of the Fragment Mass Analyzer. In addition to the ground-state band observed up to $I^{\pi }={10}^{+}$ (tentatively ${12}^{+}$), five states are proposed to belong to the $3^{-}$ band. The mirror energy differences with the analog states in ${}^{46}\mathrm{Ti}$ present a pronounced staggering effect between the odd and even spin members that is reproduced well by shell-model calculations incorporating the different Coulomb contributions, monopole, multipole, and single-particle effects together with an isospin-nonconserving interaction that accounts for the so-called $J=2$ anomaly. Dramatically different $E1$ decay patterns for members of the $3^{-}$ band between the ${}^{46}\mathrm{Cr}$ and ${}^{46}\mathrm{Ti}$ mirrors are also observed.

The structure of the neutron-deficient ${}^9\mathrm{C}$ isotope was studied via elastic scattering of radioactive ${}^8\mathrm{B}$ on protons. An excitation function for resonance elastic scattering was measured in the energy range from 0.5 to 3.2 MeV in the center-of-momentum system. A new excited state in ${}^9\mathrm{C}$ was observed at an excitation energy of 3.6 MeV. An $R$-matrix analysis indicates spin-parity $5/2^{-}$ for the new state. The results of this experiment are compared with continuum shell-model calculations.

We have measured the cross sections for the ${}^{197}\mathrm{Au}$($\alpha ,\gamma$)${}^{201}\mathrm{Tl}$ and ${}^{197}\mathrm{Au}$($\alpha ,2n$)${}^{199}\mathrm{Tl}$ reactions in the 17.9- to 23.9-MeV energy range, and ${}^{197}\mathrm{Au}$($\alpha ,n$)${}^{200}\mathrm{Tl}$ reaction in the 13.4- to 23.9-MeV energy range using an activation technique. Thick-target yields for the ${}^{64}\mathrm{Zn}$($\alpha ,\gamma$)${}^{68}\mathrm{Ge}$ (7- to 14-MeV) and ${}^{63}\mathrm{Cu}$($\alpha ,\gamma$)${}^{67}\mathrm{Ga}$ (7-MeV) reactions were measured. For all measurements, natural elements were bombarded with He${}^{+}$ beams from the 88 In. Cyclotron at the Lawrence Berkeley National Laboratory (LBNL). Irradiated samples were counted using a γ-spectrometry system at LBNL's Low Background Facility. Measured ${}^{197}\mathrm{Au}$($\alpha ,\gamma$)${}^{201}\mathrm{Tl}$ cross sections were compared with the NON-SMOKER theoretical values. The thick-target yields for the ${}^{64}\mathrm{Zn}$($\alpha ,\gamma$)${}^{68}\mathrm{Ge}$ and ${}^{63}\mathrm{Cu}$($\alpha ,\gamma$)${}^{67}\mathrm{Ga}$ reactions are also compared with the theoretical yield, calculated numerically using the energy dependent NON-SMOKER cross section data. In both cases, measured values are found to follow a trend of overlapping the predicted value near the alpha nucleus barrier height and fall below with a slowly widening difference between them in the sub-barrier energy points.

The nucleosynthesis of nature's rarest isotope ${}^{180}\mathrm{Ta}$ depends sensitively on the temperature of the astrophysical environment because of depopulation of the long-living isomeric state via intermediate states to the short-living ground state by thermal photons. Reaction rates for this transition have been measured in the laboratory. These ground state rates understimate the stellar rates dramatically because under stellar conditions intermediate states are mainly populated by excitations from thermally excited states in ${}^{180m}\mathrm{Ta}$. Full thermalization of ${}^{180}\mathrm{Ta}$ is already achieved for typical s-process temperatures around $\mathit{kT}=25$ keV. Consequently, for the survival of ${}^{180}\mathrm{Ta}$ in the s-process fast convective mixing is required which has to transport freshly synthesized ${}^{180}\mathrm{Ta}$ to cooler regions. In supernova explosions ${}^{180}\mathrm{Ta}$ is synthesized by photon- or neutrino-induced reactions at temperatures above $T_9=1$ in thermal equilibrium; independent of the production mechanism, freeze-out from thermal equilibrium occurs at $\mathit{kT}\approx 40$ keV, and only $35\pm 4$% of the synthesized ${}^{180}\mathrm{Ta}$ survive in the isomeric state.

The Hohenberg-Kohn theorem and Kohn-Sham procedure are extended to functionals of the localized intrinsic density of a self-bound system such as a nucleus. After defining the intrinsic-density functional, we modify the usual Kohn-Sham procedure slightly to evaluate the mean-field approximation to the functional, and carefully describe the construction of the leading corrections for a system of fermions in one dimension with a spin-degeneracy equal to the number of particles $N$. Despite the fact that the corrections are complicated and nonlocal, we are able to construct a local Skyrme-like intrinsic-density functional that, while different from the exact functional, shares with it a minimum value equal to the exact ground-state energy at the exact ground-state intrinsic density, to next-to-leading order in $1/N$. We briefly discuss implications for real Skyrme functionals.

Fission fragments of $1A\mathrm{GeV}$${}^{238}\mathrm{U}$ nuclei interacting with a deuterium target have been investigated with the Fragment Separator (FRS) at Gesellschaft für Schwerionenforschung (GSI) by measuring their isotopic production cross sections and velocities. Results, along with those obtained recently for spallation-evaporation fragments, provide a comprehensive analysis of the spallation nuclear productions in this reaction. Details about the experimental performance, data reduction and results are presented.

The pion double charge exchange amplitude is evaluated in a composite-meson model based on the four-quark interaction. The model assumes that the mesons are two-quark systems and can interact with each other only through quark loops. To evaluate the meson exchange current contribution, the form factors of the two-pion decay modes of the $\rho ,\sigma$, and $f_0$ mesons have been used in the calculations. The contribution of the four-quark box diagram has been taken into account as well as a contact diagram. The contributions of the $\rho ,\sigma$, and $f_0$ mesons increase the forward scattering cross section, which depends weakly on the energy.

A controlled and precise determination of the cross sections of the fusion reactions ${}^7\mathrm{Be}$$(p,\gamma )$${}^8\mathrm{B}$ and ${}^3\mathrm{He}$(${}^4\mathrm{He}$,$\gamma$)${}^7\mathrm{Be}$, which play an important role in determining the solar neutrino flux, necessitates the knowledge of a precise value of the electron-capture half-life of ${}^7\mathrm{Be}$. This half-life may depend on the material hosting the ${}^7\mathrm{Be}$ atoms via small modifications of the electron density around the ${}^7\mathrm{Be}$ nucleus. In this brief communication we report on the measurement of ${}^7\mathrm{Be}$ implanted in four materials: copper, aluminum, sapphire, and PVC. The four results are consistent with a null host dependence within two standard deviations and their weighted average of 53.236(39) d agrees very well with the adopted value in the literature, 53.22(6) d. The present results may exhibit a slight (0.22%) increase of the half-life at room temperature for metals compared to insulators that requires further studies.

We introduce a combined, fully three-dimensional macroscopic/microscopic transport approach employing relativistic 3D hydrodynamics for the early, dense, deconfined stage of the reaction and a microscopic nonequilibrium model for the later hadronic stage where the equilibrium assumptions are no longer valid. Within this approach, we study the dynamics of hot bulk QCD matter, which is being created in ultrarelativistic heavy-ion collisions at the BNL Relativistic Heavy-Ion Collider. Our work is an extension of the well-known hybrid macro+micro approach in 1+1 and 2+1 dimensions, which is capable of self-consistently calculating the freeze-out of the hadronic system while accounting for the collective flow on the hadronization hypersurface generated by the quark-gluon plasma expansion. In particular, we perform a detailed analysis of the reaction dynamics, hadronic freeze-out, and transverse flow.

We present a phenomenological model of the quark-hadron transition in neutrino-nucleon scattering. Using recently extracted weak nucleon transition form factors, we investigate the extent to which local and global quark-hadron duality is applicable in the neutrino $F_1,F_2$, and $F_3$ structure functions and contrast this with duality in electron scattering. Our findings suggest that duality works relatively well for neutrino-nucleon scattering for the $F_2$ and $F_3$ structure functions but not as well for $F_1$. We also calculate the quasielastic, resonance, and deep inelastic contributions to the Adler sum rule and find it to be satisfied to within 10% for $0.5\lesssim Q^2\lesssim 2{\mathrm{GeV}}^2$.

We examine how the properties of inhomogeneous nuclear matter at subnuclear densities depend on the density dependence of the symmetry energy. Using a macroscopic nuclear model we calculate the size and shape of nuclei in neutron star matter at zero temperature in a way dependent on the density dependence of the symmetry energy. We find that for smaller symmetry energy at subnuclear densities, corresponding to the larger density symmetry coefficient $L$, the charge number of nuclei is smaller and the critical density at which matter with nuclei or bubbles becomes uniform is lower. The decrease in the charge number is associated with the dependence of the surface tension on the nuclear density and the density of a sea of neutrons, whereas the decrease in the critical density can be generally understood in terms of proton clustering instability in uniform matter.

The low-spin structure of ${}^{93}\mathrm{Nb}$ has been studied using the ${}^{93}\mathrm{Nb}$$(\gamma ,{\gamma }^{\text{'}})$, ${}^{93}\mathrm{Nb}$$(n,n^{\text{'}}\gamma )$ and ${}^{94}\mathrm{Zr}$$(p,2n\gamma \gamma )$${}^{93}\mathrm{Nb}$ reactions. Lifetimes were determined from both ${}^{93}\mathrm{Nb}$$(\gamma ,{\gamma }^{\text{'}})$ and ${}^{93}\mathrm{Nb}$$(n,n^{\text{'}}\gamma )$ measurements. Branching ratios were measured, and multipolarities and spin assignments were determined from the ${}^{94}\mathrm{Zr}$$(p,2n\gamma \gamma )$${}^{93}\mathrm{Nb}$ angular correlation experiment. From $M1$ and $E2$ strengths, the $J^{\pi }=9/2^{+}$ and $7/2^{+}$ states at 1297.1 keV and 1483.6 keV, respectively, are proposed as members of the quintet of mixed-symmetry states associated with the $\pi 1g_{9/2}\otimes (2_{1,\mathrm{MS}}^{+}$,${}^{92}\mathrm{Zr}$) configuration. The large $B(M1)$ values determined in ${}^{93}\mathrm{Nb}$ cannot be explained within the weak coupling limit of the interacting boson fermion model.

We consider the pairing Hamiltonian and systematically construct its density functional in the strong-coupling limit and in the limit of large particle numbers. In the former limit, the functional is an expansion into central moments of occupation numbers. In the latter limit, the functional is known from BCS theory. Both functionals are nonlocal in structure, and the nonlocalities are in the form of simple products of local functionals. We also derive the relation between the occupation numbers and the Kohn-Sham density.