Excited states in ${}^{107}\mathrm{Mo}$, populated in spontaneous fission of ${}^{248}\mathrm{Cm}$, were studied by use of the eurogam2 multidetector array. Spins and parities of the ground state and the 66.0-, 152.1-, and 458.5-keV excited levels, reported previously, were changed based on conversion-coefficient and angular-correlation measurements. Octupole deformation reported previously in ${}^{107}\mathrm{Mo}$ is dismissed, and we explain the near-yrast structure of ${}^{107}\mathrm{Mo}$ in terms of rotational bands built on the ${5/2}^{+}$[413], ${3/2}^{+}$[411], and ${7/2}^{-}$[523] orbitals.

We study the generalized parton distributions, including the helicity-fiip ones, using the Nambu–Jona-Lasinio (NJL) model based on a relativistic Faddeev approach with “static approximation.” Sum rules relating the generalized parton distributions to nucleon electromagnetic form factors are satisfied. Moreover, quark-antiquark contributions in the region $-\xi <x<\xi$ are nonvanishing. Our results are qualitatively similar to those calculated with Radyushkin's double distribution ansatz using forward parton distribution functions calculated in the NJL model as inputs.

We investigate $K^{+}$-nucleus elastic scattering at intermediate energies within a microscopic optical model approach using the current $K^{+}$-nucleon (KN) phase shifts from the Center for Nuclear Studies of the George Washington University as primary input. The KN phase shifts are used to generate Gel'fand-Levitan-Marchenko real and local inversion potentials. These potentials are supplemented with a short-range, complex separable term in such a way that the corresponding unitary and nonunitary $\mathit{KN\; S}$ matrices are exactly reproduced. These KN potentials allow us to calculate all needed on- and off-shell contributions of the t matrix, the driving effective interaction in the full-folding $K^{+}$-nucleus optical model potentials reported here. Elastic scattering of positive kaons from ${}^6\mathrm{Li}$, ${}^{12}\mathrm{C}$, ${}^{28}\mathrm{Si}$, and ${}^{40}\mathrm{Ca}$ are studied at beam momenta in the range 400–1000 MeV/c, leading to a fair description of most differential and total cross section data. To complete the analysis of the full-folding model, three kinds of simpler $t\rho$ calculations are considered and the results are discussed.

A dynamical model [T. Sato and T.-S. H. Lee, Phys. Rev. C 54, 2660 (1996); 63, 055201 (2001); T. Sato, D. Uno, and T.-S. H. Lee, ibid. 67, 065201 (2003)] of electroweak pion production reactions in the Δ(1232) region has been extended to include the neutral current contributions for examining the local quark-hadron duality in neutrino-induced reactions and for investigating how the axial $N\text{−}\Delta$ form factor can be determined by the parity violating asymmetry of $N(\overrightarrow{e},e^{\text{'}})$ reactions. We first show that the recent data of $(e,e^{\text{'}})$ structure functions $F_1$ and $F_2$, which exhibit the quark-hadron duality, are in good agreement with our predictions. For possible future experimental tests, we then predict that the structure functions $F_1,F_2$, and $F_3$ for $(\nu ,e)$ and $(\nu ,{\nu }^{\text{'}})$ processes also show the similar quark-hadron duality. The spin-dependent structure functions $g_1$ and $g_2$ of $(e,e^{\text{'}})$ have also been calculated from our model. It is found that the local quark-hadron duality is not seen in the calculated $g_1$ and $g_2$, while our results for $g_1$ and some polarization observables associated with the exclusive $p(\overrightarrow{e},e^{\text{'}}\pi )$ and $\overrightarrow{p}(\overrightarrow{e},e^{\text{'}}\pi )$ reactions are in reasonably good agreement with the recent data. In the study of parity violating asymmetry A of $N(\overrightarrow{e},e^{\text{'}})$ reactions, the relative importance between the nonresonant mechanisms and the Δ excitation is investigated by taking into account the unitarity condition. Predictions are made for using the data of A to test the axial $N\text{−}\Delta$ form factors determined previously in the studies of $N({\nu }_{\mu },{\mu }^{-}\pi )$ reactions. The predicted asymmetry A are also compared with the parton model predictions for future experimental investigations of quark-hadron duality.

We analyze the long-wavelength response of a normal Fermi liquid using Landau theory. We consider contributions from intermediate states containing one additional quasiparticle-quasihole pair as well as those from states containing two or more additional quasiparticle-quasihole pairs. For the response of an operator corresponding to a conserved quantity, we show that the behavior of matrix elements to states with more than one additional quasiparticle-quasihole pair at low excitation energies $\omega$ varies as $1/\omega$. It is shown how rates of processes involving transitions to two quasiparticle-quasihole states may be calculated in terms of the collision integral in the Landau transport equation for quasiparticles.

In this paper we analyze the nuclear fusion rates among equal nuclei for all five different nuclear burning regimes in dense matter (two thermonuclear regimes, two pycnonuclear ones, and the intermediate regime). The rate is determined by Coulomb barrier penetration in dense environments and by the astrophysical S factor at low energies. We evaluate previous studies of the Coulomb barrier problem and propose a simple phenomenological formula for the reaction rate that covers all cases. The parameters of this formula can be varied to take into account current theoretical uncertainties in the reaction rate. The results are illustrated for the example of the ${}^{12}\mathrm{C}$+${}^{12}\mathrm{C}$ fusion reaction. This reaction is important for the understanding of nuclear burning in evolved stars, in exploding white dwarfs producing type Ia supernovas, and in accreting neutron stars. The S factor at stellar energies depends on a reliable fit and extrapolation of the experimental data. We calculate the energy dependence of the S factor by using a recently developed parameter-free model for the nuclear interaction, taking into account the effects of the Pauli nonlocality. For illustration, we analyze the efficiency of carbon burning in a wide range of densities and temperatures of stellar matter with the emphasis on carbon ignition at densities $\rho \gtrsim {10}^9$ g cm${}^{-3}$.

We show that, the new experimental information reported by Saha et al. [Phys. Rev. C 70, 034313 (2004)] strongly supports the idea that the dipole band in ${}^{124}\mathrm{Xe}$ is a magnetic rotational band of intermediate nature, i.e., comparable amounts of angular momentum are generated by the shears mechanism and by the collective rotation.

The chiral SU(3) quark model is extended to include the coupling between the quark and vector chiral fields. The one-gluon exchange (OGE) that dominantly governs the short-range quark–quark interaction in the original chiral SU(3) quark model is now nearly replaced by the vector-meson exchange. By use of this model, the isospin $I=0$ and $I=1$ kaon-nucleon $S,P,D,F$ wave phase shifts are dynamically studied by solving the resonating group method (RGM) equation. Similar to those given by the original chiral SU(3) quark model, the calculated results for many partial waves are consistent with the experiment, while there is no improvement in this new approach for the $P_{13}$ and $D_{15}$ channels, of which the theoretical phase shifts are too repulsive and too attractive, respectively, when the laboratory momentum of the kaon meson is greater than 300 MeV.

A QCD-motivated dynamical-quasiparticle model with parameters adjusted to reproduce the lattice-QCD equation of state is extrapolated from the region of high temperatures and moderate baryonic densities to the domain of high baryonic densities and zero temperature. The resulting equation of state matched with realistic hadronic equations of state predicts a phase transition into the quark phase at higher densities than those reachable in neutron star interiors. This excludes the possibility of the existence of hybrid (hadron-quark) stars. Pure quark stars are possible and have low masses, small radii, and very high central densities. Similar results are obtained for a simple bag model with massive quarks, fitted to reproduce the same lattice results. Self-bound quark matter is also excluded within these models. Uncertainties in the present extrapolation are discussed. Comparison with standard bag models is made.

The inclusive energy distributions of fragments with Z $\ge$ 3 emitted from the bombardment of ${}^{12}\mathrm{C}$ by ${}^{20}\mathrm{Ne}$ beams with incident energies between 145 and 200 MeV have been measured in the angular range ${\theta }_{\mathrm{lab}}~{10}^{°}\text{−}{50}^{°}$. Damped fragment yields in all cases have been found to be characteristic of emission from fully energy equilibrated composites; for B and C fragments, average Q values, $\langle Q\rangle$, were independent of the center-of-mass emission angle (${\theta }_{\mathrm{c.m}.}$), and the angular distributions followed a $~1/\sin {\theta }_{\mathrm{c.m}.}$-like variation, signifying long lifetimes of the emitting dinuclear systems. Estimates of total yields of these fragments have been found to be much larger than those predicted by the standard statistical model. This may be indicative of the survival of an orbiting-like process in the ${}^{12}\mathrm{C}+{}^{20}\mathrm{Ne}$ system at these energies.

Bulk and single-particle properties of hot hyperonic matter are studied within the Brueckner-Hartree-Fock approximation extended to finite temperature. The bare interaction in the nucleon sector is the Argonne V18 potential supplemented with an effective three-body force to reproduce the saturating properties of nuclear matter. The modern Nijmegen NSC97e potential is employed for the hyperon-nucleon and hyperon-hyperon interactions. The effect of temperature on the in-medium effective interaction is found to be, in general, very small and the single-particle potentials differ by at most 25% for temperatures in the range from 0 to 60 MeV. The bulk properties of infinite matter of baryons, either nuclear isospin symmetric or a β-stable composition that includes a nonzero fraction of hyperons, are obtained. It is found that the presence of hyperons can modify the thermodynamical properties of the system in a non-negligible way.

Previous studies of the extent of isospin mixing in preequilibrium reactions in the continuum have concentrated on reactions with nucleons in both the entrance and exit channels and with incident energies of 30 MeV or less. Using an expanded database for light-particle reactions that includes complex particle channels and higher incident energies, a new investigation of preequilibrium and, at the lower incident energies, equilibrium mechanisms has been carried out. Although many of the measured inclusive energy spectra are insensitive to whether isospin is assumed to be mixed or conserved during the reaction, other spectra reveal evidence that isospin is conserved during the preequilibrium phase of a reaction when the excitation energy in the intermediate nucleus is less than four times the symmetry energy. When isospin is conserved during energy equilibration, good agreement with experiment is typically obtained when the corresponding amount of isospin conservation at equilibrium is taken to be around 40%, though this number is model dependent.

The low-energy fusion cross sections of charged-particle nuclear reactions (and the respective reaction rates) in stellar plasmas are enhanced because of plasma screening effects. We study the impact of those effects on predictive stellar evolution simulations for detached double-lined eclipsing binaries. We follow the evolution of binary systems (pre-main-sequence or main-sequence stars) with precisely determined radii and masses from 1.1 to 23 $M_{\odot }$ (from their birth until their present state). The results indicate that all the discrepancies between the screened and unscreened models (in terms of luminosity, stellar radius, and effective temperature) are within the observational uncertainties. Moreover, no nucleosynthetic or compositional variation was found to be due to screening corrections. Therefore all thermonuclear screening effects on the charged-particle nuclear reactions that occur in the binary stars considered in this work (from their birth until their present state) can be totally disregarded. In other words, all relevant charged-particle nuclear reactions can be safely assumed to take place in a vacuum, thus simplifying and accelerating the simulation processes.

The nuclear structure of the $\Delta I=1$ doublet bands in doubly-odd nuclei ${}^{130}\mathrm{Cs}$, ${}^{132}\mathrm{Cs}$, ${}^{132}\mathrm{La}$, and ${}^{134}\mathrm{La}$ is studied in terms of a pair-truncated shell model, in which the collective nucleon pairs with angular momenta of zero and two are its basic ingredients. The effective interactions consist of single-particle energies and monopole and quadrupole pairing plus quadrupole-quadrupole interactions, whose strengths are determined so as to describe the level schemes of even-even nuclei in the mass $A~130$ region. The calculation reproduces well the energy levels of the doublet bands and the electromagnetic transitions, especially the staggering of the ratios $B(M1;I\to I-1)/B(E2;I\to I-2)$ for the yrast states. Through the analysis of the wave functions, the doublet bands turn out to be made of different angular momentum configurations of an unpaired neutron and an unpaired proton, weakly coupled with the quadrupole collective excitations of the even-even part of the nucleus.

The proximity potential is obtained in the form of the generalized “pocket formula” for a collision between any two symmetric or asymmetric mass, deformed and noncoplanar (including also the case of coplanar) nuclei, having the fixed orientations ${\theta }_1$ and ${\theta }_2$ and any azimuthal angle $\varphi (=0^{°}-{90}^{°}$). The method is applied first to some illustrative axially symmetric noncoplanar nuclei with the known “gentle”- and “hugging”-fusion configurations (${\theta }_1={\theta }_2={90}^{°},\varphi ={90}^{°}$). The very general case of noncoplanar nuclei having any orientation and azimuthal angles is also discussed. Application of the method to a specific reaction that has been used in experiments for synthesizing a superheavy nucleus is also made.

Statistical mechanics (SM) of Yang-Mills classical mechanics is studied by using a toy model that resembles chaotic quartic oscillators. This nonlinear system attains the thermodynamic equilibrium not by collisions, which is generally assumed in SM, but by chaotic dynamics. This is a new mechanism of thermalization that may be relevent to the quark-gluon plasma (QGP) formation in relativistic heavy-ion collisions because the interactions governing QGP involve quantum chromodynamics (QCD), which is a Yang-Mills theory [SU(3)]. The thermalization time is estimated from the Lyapunov exponent. The Lyapunov exponent is evaluated using the recently developed monodromy matrix method. We also discuss the physical meaning of thermalization and SM in this system of few degrees in terms of chromo-electric and chromomagnetic fields. One of the consequence of thermalization, such as equipartition of energy and dynamical temperature, is also numerically verified.

We explore the centrality dependence of the properties of the dense hadronic matter created in $\sqrt{s_{\mathit{NN}}}=200$ GeV Au-Au collisions at the Relativistic Heavy Ion Collider. Using the statistical hadronization model, we fit particle yields known for 11 centrality bins. We present the resulting model parameters, rapidity yields of physical quantities, and the physical properties of bulk matter at hadronization as function of centrality. We discuss the production of strangeness and entropy.

The photon-proton scattering reactions $\gamma p\to {\pi }^{o}p,\gamma p\to \gamma p$, and $\gamma p\to \gamma {\pi }^{o}p$ are investigated in the framework of the three-dimensional time-ordered approach using different models of the on-shell Δ propagators. These Δ propagators are taken from the unitary separable models of the $\pi N$ elastic-scattering amplitude and from the relativistic Breit-Wigner shape representation of the nonunitary $\pi N$ amplitude in the tree approach. The numerical calculations are performed with the complete set of the one-particle ($\pi \text{−},\omega \text{−},\text{and}\rho$-meson, nucleon, and Δ) exchange diagrams. It is found that the numerical calculations of the above reactions in the Δ-resonance region are very sensitive to the model of the Δ propagator. This sensitivity is explained by the difference between the input $\pi N$ elastic-scattering observables used for the construction of the Δ propagator. It is shown, that after additional approximation our calculations reproduce the tree-level model calculations with the Breit-Wigner shape Δ propagator. This model is in good agreement with the $\gamma p\to {{\pi }^o}^{\text{'}}{p}^{\text{'}}$ reaction and with the preliminary data for the $\gamma p\to {\gamma }^{\text{'}}{{\pi }^o}^{\text{'}}{p}^{\text{'}}$ reaction. Conversely, it is demonstrated, that the relativistic Breit-Wigner shape Δ propagators, obtained from the nonunitary $\pi N$ amplitudes in the tree approximation, is inconsistent to apply for reproduction of the $\gamma p$ scattering observables because they do not describe the $\pi N$ scattering data in the Δ resonance region. It is emphasized, that to extract the magnitude of the ${\Delta }^{+}$ magnetic moment from the cross sections of the $\gamma p\to {\gamma }^{\text{'}}{\pi }^{\text{'}}{N}^{\text{'}}$ reaction it is necessary to fix the form of the Δ propagator based on the unified description of the two body $\pi p\to \pi N,\gamma p\to \pi N$ basic channels together with the essential $\gamma p\to \pi \pi N$ and $\gamma p\to \gamma p$ reactions.

The analyzing power $A_y(\theta )$ for neutron elastic scattering from ${}^{12}\mathrm{C}$ has been measured for 33 neutron energies between $E_n=2.2$ and 8.5 MeV in the angular range from 25${}^{°}$ to 145${}^{°}$ in the laboratory system. The primary motivation for these measurements is the need for an accurate knowledge of $A_y(\theta )$ for ${}^{12}\mathrm{C}$$(n,n)$${}^{12}\mathrm{C}$ elastic scattering to enable corrections to high-precision neutron-proton and neutron-deuteron $A_y(\theta )$ data in the neutron-energy range below $E_n=30$ MeV. In their own right, ${}^{12}\mathrm{C}$$(n,n)$${}^{12}\mathrm{C}$ $A_y(\theta )$ data are of crucial importance for improving both the parametrization of $n\text{−}$${}^{12}\mathrm{C}$ scattering and our knowledge of the level scheme of ${}^{13}\mathrm{C}$. The present $A_y(\theta )$ data are compared with published data and previous phase-shift-analysis results.