We include a generalized infinite class of quark-gluon vertex dressing diagrams in a study of how dynamics beyond the ladder-rainbow truncation influences the Bethe-Salpeter description of light-quark pseudoscalar and vector mesons. The diagrammatic specification of the vertex is mapped into a corresponding specification of the Bethe-Salpeter kernel, which preserves chiral symmetry. This study adopts the algebraic format afforded by the simple interaction kernel used in previous work on this topic. The new feature of the present work is that in every diagram summed for the vertex and the corresponding Bethe-Salpeter kernel, each quark-gluon vertex is required to be the self-consistent vertex solution. We also adopt from previous work the effective accounting for the role of the explicitly non-Abelian three-gluon coupling in a global manner through one parameter determined from recent lattice-QCD data for the vertex. Within the current model, the more consistent dressed vertex limits the ladder-rainbow truncation error for vector mesons to be never more than 10% as the current quark mass is varied from the $u/d$ region to the $b$ region.

The Gamow peak represents one of the most important concepts in the study of thermonuclear reactions in stars. It is widely used in order to determine, at a given plasma temperature, the effective stellar energy region in which most charged-particle induced nuclear reactions occur. It is of importance in the design of nuclear astrophysics measurements, including those involving radioactive ion beams, and for the determination of stellar reaction rates. We demonstrate that the Gamow peak concept breaks down under certain conditions if a nuclear reaction proceeds through narrow resonances at elevated temperatures. It is shown that an effective stellar energy window does indeed exist in which most thermonuclear reactions take place at a given temperature, but that this energy window can differ significantly from the commonly used Gamow peak. We expect that these findings are especially important for thermonuclear reactions in the advanced burning stages of massive stars and in explosive stellar environments.

The superscaling observed in inclusive electron scattering is described within the dilute Fermi gas model with interaction between the particles. The comparison with the relativistic Fermi gas (RFG) model without interaction shows an improvement in the explanation of the scaling function $f({\psi }^{\prime })$ in the region ${\psi }^{\prime }<-1$, where the RFG result is $f({\psi }^{\prime })=0$. It is found that the behavior of $f({\psi }^{\prime })$ for ${\psi }^{\prime }<-1$ depends on the particular form of the general power-law asymptotics of the momentum distribution $n(k)\sim 1/k^{4+m}$ at large $k$. The best agreement with the empirical scaling function is found for $m\simeq 4.5$ in agreement with the asymptotics of $n(k)$ in the coherent density fluctuation model where $m=4$. Thus, superscaling gives information about the asymptotics of $n(k)$ and the $\mathit{NN}$ forces.

The atomic electric dipole moment (EDM) is evaluated by considering the relativistic effects as well as nuclear finite size effects in Xe and Hg atomic systems. Due to Schiff's theorem, the first order perturbation energy of EDM is canceled out by the second order perturbation energy for the point nucleus. The nuclear finite size effects arising from the intermediate atomic excitations may be finite for deformed nucleus but it is extremely small. The finite size contribution of the intermediate nuclear excitations in the second order perturbation energy is completely canceled by the third order perturbation energy. As the results, the finite contribution to the atomic EDM comes from the first order perturbation energy of relativistic effects, and it amounts to around 0.3 and 0.4 percents of the neutron EDM $d_n$ for Xe and Hg, respectively, though the calculations are carried out with a simplified single-particle nuclear model. From this relation in Hg atomic system, we can extract the neutron EDM which is found to be just comparable with the direct neutron EDM measurement.

The ${}^{17}\mathrm{O}$($p,\alpha$)${}^{14}\mathrm{N}$ and ${}^{17}\mathrm{O}$($p,\gamma$)${}^{18}\mathrm{F}$ reactions are of major importance to hydrogen-burning nucleosynthesis in a number of different stellar sites. In particular, ${}^{17}\mathrm{O}$ and ${}^{18}\mathrm{F}$ nucleosynthesis in classical novae is strongly dependent on the thermonuclear rates of these two reactions. The previously estimated rate for ${}^{17}\mathrm{O}$($p,\alpha$)${}^{14}\mathrm{N}$ carries very large uncertainties in the temperature range of classical novae ($T=0.01$–0.4 GK), whereas a recent measurement has reduced the uncertainty of the ${}^{17}\mathrm{O}$($p,\gamma$)${}^{18}\mathrm{F}$ rate. We report on the observation of a previously undiscovered resonance at $E_{c.m.}=183.3$ keV in the ${}^{17}\mathrm{O}$($p,\alpha$)${}^{14}\mathrm{N}$ reaction, with a measured resonance strength $\omega {\gamma }_{p\alpha }=(1.6\pm 0.2)\times {10}^{-3}$ eV. We studied in the same experiment the ${}^{17}\mathrm{O}$($p,\gamma$)${}^{18}\mathrm{F}$ reaction by an activation method, and the resonance strength was found to amount to $\omega {\gamma }_{p\gamma }=(2.2\pm 0.4)\times {10}^{-6}$ eV. The excitation energy of the corresponding level in ${}^{18}\mathrm{F}$ was determined to be $5789.8\pm 0.3$ keV in a Doppler shift attenuation method measurement, which yielded a value of $\tau <2.6$ fs for the level lifetime. The ${}^{17}\mathrm{O}$($p,\alpha$)${}^{14}\mathrm{N}$ and ${}^{17}\mathrm{O}$($p,\gamma$)${}^{18}\mathrm{F}$ reaction rates were calculated using the measured resonance properties and reconsidering some previous analyses of the contributions of other levels or processes. The ${}^{17}\mathrm{O}$($p,\alpha$)${}^{14}\mathrm{N}$ rate is now well established below $T=1.5$ GK, with uncertainties reduced by orders of magnitude in the temperature range $T=0.1$–0.4 GK. The uncertainty in the ${}^{17}\mathrm{O}$($p,\gamma$)${}^{18}\mathrm{F}$ rate is somewhat larger because of remaining obscurities in the knowledge of the direct capture process. These new resonance properties have important consequences for ${}^{17}\mathrm{O}$ nucleosynthesis and γ-ray emission of classical novae.

The ${}^{36}\mathrm{Cl}$($n,p$)${}^{36}\mathrm{S}$ and ${}^{36}\mathrm{Cl}$($n,\alpha$)${}^{33}\mathrm{P}$ reaction cross sections have been studied with resonance neutrons at the linear accelerator GELINA of the IRMM in Geel (Belgium) and have been determined up to approximately 250 keV using the time-of-flight technique. In this energy region, 17 resonances were observed, whereas eight were identified before. For some resonances the resonance strength, the spin, and the total width could be determined. From the obtained cross section data, the MACS has been calculated by numerical integration. These updated MACS values were used in stellar models to trace the origin of the rare isotope ${}^{36}\mathrm{S}$.

We analyze the equation of state in terms of quasiparticles with continuously distributed mass. We seek for a description of the entire pressure-temperature curve at vanishing chemical potential in terms of a temperature independent mass distribution. We point out properties indicating a mass gap in this distribution, conjectured to be related to confinement.

We study the long range part of the Λ-hyperon optical potential in nuclei using quantum many body techniques and flavor-SU(3) chiral Lagrangians as starting point. More precisely, we study the contributions to the Λ-hyperon optical potential due to the long-range two-pion exchange, with Σ and ${\Sigma }^{*}$ baryons in the internal baryonic lines and considering $\mathit{Nh}$ and $\Delta h$ excitations. We also consider the contribution to the spin-orbit potentials that comes out from these terms. Our results support a natural explanation of the smallness of the Λ-nuclear spin-orbit interaction and show the importance of the ${\Sigma }^{*}$ and Δ degrees of freedom for the hyperon-nucleus interactions.

The nucleus ${}^{126}\mathrm{Cs}$ was investigated by means of in-beam γ-ray spectroscopy techniques using the Nordball detector system at the Niels Bohr Institute. Excited states of ${}^{126}\mathrm{Cs}$ were populated via the ${}^{116}\mathrm{Cd}$(${}^{14}\mathrm{N}$, $4n$)${}^{126}\mathrm{Cs}$ reaction at a beam energy of 65 MeV. The ${}^{126}\mathrm{Cs}$ level scheme was considerably extended, especially at negative parity and about 40 new levels and 70 new transitions were added into the level scheme. The previously reported negative-parity rotational bands, built on $\pi g_{7/2}\otimes \nu h_{11/2},\pi d_{5/2}\otimes \nu h_{11/2},\pi h_{11/2}\otimes \nu g_{7/2}$, and $\pi h_{11/2}\otimes \nu d_{5/2}$ configurations, have been extended and evolve into bands involving rotationally aligned $(\pi h_{11/2}){}^2$ and $(\nu h_{11/2}){}^2$ quasiparticles. Two new rotational bands have been tentatively assigned the $\pi h_{11/2}\otimes \nu s_{1/2}$ and $\pi g_{9/2}\otimes \nu h_{11/2}$ configurations, respectively.

We demonstrate based on a microscopic α-cluster model that α-condensed states appear not only in light nuclei such as ${}^{12}\mathrm{C}$ and ${}^{16}\mathrm{O}$ but also in heavier nuclei with a core at excitation energies corresponding to multi-α-threshold energies. To extend the study of normal α-condensed state to the cases of heavier nuclei with an inner strongly bound core (${}^{16}\mathrm{O}$) and also to non-4$N$-nuclei (e.g., 2α+dineutron), we introduce a Monte Carlo technique for the description of the Schuck wave function, which are called “virtual Schuck” wave function.

We study contributions of poles and continua of the single-particle states to the wave function obtained by the cluster-orbital shell model (COSM). The COSM wave function is described in terms of a linear combination of nonorthogonal Gaussian basis sets. We study oxygen and helium isotopes as examples of normal and weakly bound nuclei. In the investigation of the contribution of the single-particle states, we expand the COSM wave function by using an extended completeness relation, which is constructed by the solution of the single-particle Hamiltonian. We use the complex scaling method to obtain the bound, resonant, and continuum states of the Hamiltonian and construct the extended completeness relation. The results are compared with those obtained by the Gamow shell model calculation.

High-spin states in ${}^{35}\mathrm{Ar}$ and ${}^{35}\mathrm{Cl}$ have been populated in the ${}^{24}\mathrm{Mg}$(${}^{16}\mathrm{O}$, $\alpha n$) and ${}^{24}\mathrm{Mg}$(${}^{16}\mathrm{O}$, $\alpha p$) reactions, respectively, at a beam energy of 70 MeV. The comparison between the level schemes of these mirror nuclei shows a striking asymmetry in the population yield of high-spin analog states of positive parity, which indicates different intensities of $E1$ transitions connecting positive- and negative-parity structures in both nuclei. Large energy differences are observed between analog states of negative parity with configurations of dominant pure single-particle character. This results from the comparison with large-scale shell-model calculations in the $s_{1/2}{d}_{3/2}{f}_{7/2}{p}_{3/2}$ valence space. It is shown that important contributions to the energy differences arise from the multipole Coulomb and the relativistic electromagnetic spin-orbit interactions.

Extensive studies of the low-spin excited states in ${}_{42}^{96}{\mathrm{Mo}}_{54}$ with the ($n,n^{\prime }\gamma$) reaction have clarified the level scheme below 3.7 MeV excitation energy and determined detailed information about ${}^{96}\mathrm{Mo}$, including lifetimes from the Doppler-shift attenuation method, branching ratios, and multipole mixing ratios. Also, $B(E2)$ and $B(M1)$ values were determined for many transitions, multiphonon states were identified, and several low-spin states were characterized in terms of collective, mixed-symmetry states.

Near-barrier fusion of neutron-rich nuclei was studied within the semiempirical channel coupling model for intermediate neutron rearrangement and within the time-dependent three-body Schrödinger equation. The possibility of neutron transfer with positive $Q$ values considerably increases the barrier penetrability. A huge enhancement of deep sub-barrier fusion probability was found for light neutron-rich weakly bound nuclei (such as ${}^6\mathrm{He}$). This may be quite important for astrophysical primordial and supernova nucleosynthesis.

High-spin states in ${}^{187}\mathrm{Pt}$ have been studied experimentally using the ${}^{173}\mathrm{Yb}$(${}^{18}\mathrm{O}$, $4n$) reaction at beam energies of 78 and 85 MeV. The previously known bands based on the $\nu i_{13/2},\nu 7/2^{-}[503]$, and $\nu i_{13/2}^2\nu j$ configurations have been extended to high-spin states, and new rotational bands associated with the $\nu 3/2^{-}[512]$ and $\nu 1/2^{-}[521]$ Nilsson orbits have been identified. The total Routhian surface calculations indicate that the transitional nucleus ${}^{187}\mathrm{Pt}$ is very soft with respect to $\beta$ and $\gamma$ deformations. The band properties, such as level spacings, band crossing frequencies, alignment gains, and signature splittings, have been compared with the systematics observed in neighboring nuclei and have been interpreted within the framework of the cranked shell model. The rotational bands show different band crossing frequencies, which can be explained by the alignment either of $i_{13/2}$ neutrons or of $h_{9/2}$ protons. Importantly, evidence is presented for a $\pi h_{9/2}$ alignment at very low frequency in the $\nu 7/2^{-}[503]$ band. The proton nature of the band crossing is strongly suggested by comparing the measured $B(M1;I\to I-1)/B(E2;I\to I-2)$ ratios with the theoretical values from the semiclassical Dönau and Frauendof approach.

The relation between energy and density (known as the nuclear equation of state) plays a major role in a variety of nuclear and astrophysical systems. Spin and isospin asymmetries can have a dramatic impact on the equation of state and possibly alter its stability conditions. An example is the possible manifestation of ferromagnetic instabilities, which would indicate the existence, at a certain density, of a spin-polarized state with lower energy than the unpolarized one. This issue is being discussed extensively in the literature and the conclusions are presently very model dependent. We will report and discuss our recent progress in the study of spin-polarized neutron matter. The approach we take is microscopic and relativistic. The calculated neutron matter properties are derived from realistic nucleon-nucleon interactions. This makes it possible to understand the properties of the equation of state in terms of specific features of the nuclear force model.

Elastic and inelastic scattering of unpolarized and polarized protons by ${}^{40}\mathrm{Ar}$ nuclei for incident energies between 20 and 50 MeV has been studied by reanalyzing experimental scattering spectra for the $2^{+}$(1.46 MeV) and $3^{-}$(3.68 MeV) levels in the angular range $30°–160°$ for incident protons of energies of 25.1, 32.5, and 40.7 MeV. An isospin dependent soft-rotator coupled-channels optical model with the potential containing a dispersive term with a nonlocal contribution is used to analyze the data.

Data for Drell-Yan (DY) processes on nuclei are currently available from fixed target experiments up to the highest energy of $\sqrt{s}=40$ GeV. The bulk of the data cover the range of short coherence length, where the amplitudes of the DY reaction on different nucleons do not interfere. In this regime, DY processes provide direct information about broadening of the transverse momentum of the projectile parton experiencing initial-state multiple interactions. We revise a previous analysis of data from the E772 experiment and perform a new analysis of broadening including data from the E866 experiment at Fermilab. We conclude that the observed broadening is about twice as large as the one found previously. This helps to settle controversies that arose from a comparison of the original determination of broadening with data from other experiments and reactions.

The nuclear resonance parameters and the capture cross section of the neutron magic isotope ${}^{139}\mathrm{La}$ have been measured relative to ${}^{197}\mathrm{Au}$ in the energy range of 0.6 eV to 9 keV at the neutron time-of-flight (n_TOF) facility at CERN. We describe the experimental apparatus and the data analysis procedures, which concerned mainly the efficiency correction by means of the pulse height weighting function technique and the determination of different background components. We extracted the resonance parameters and the main nuclear quantities such as the resonance integral $\mathrm{RI}=10.8\pm 1.0b$, the average γ widths for $s$ and $p$ waves $\langle {\Gamma }_{\gamma }\rangle {}_{l=0}=50.7\pm 5.4$ meV and $\langle {\Gamma }_{\gamma }\rangle {}_{l=1}=33.6\pm 6.9$ meV, the nuclear level densities $\langle D\rangle {}_{l=0}=252\pm 22$ eV and $\langle D\rangle {}_{l=1}<250$ eV, and the neutron strength functions $S_0=(0.82\pm 0.05)\times {10}^{-4}$ and $S_1=(0.55\pm 0.04)\times {10}^{-4}$. These results represent a significant improvement over previous data. The deduced Maxwellian-averaged capture cross sections are important for the interpretation of the most recent spectroscopic observations in low-metallicity stars.

We investigate the phase transition to a deconfined phase and the consequences in the formation of neutron stars. We use the recently proposed effective-field-theory-motivated relativistic mean-field theory for the hadrons and the MIT bag model and color-flavor locked (CFL) phase for the quark matter to get the appropriate equation of state. The properties of the stars are then calculated. The differences between unpaired and CFL quark matter are discussed.