A systematic study of isotope temperatures has been presented for heavy-ion collisions at 600 MeV/nucleon via the isospin-dependent quantum molecular dynamics model in the company of the statistical decay model (GEMINI). We find that the isospin dependence of the isotope temperatures in multifragmentation is weak; however, this effect is still visible over a wide isotopic range. The isotope temperatures for the neutron-rich projectiles are larger than those for the neutron-poor projectiles. We also find that the isotope temperatures calculated by the model decrease with increasing nuclear mass.

The attenuation of $\omega$ mesons in cold nuclear matter has been investigated via the time-dependent multiple-scattering Monte Carlo multicollisional (MCMC) intranuclear cascade model. The inelastic $\omega$ width deduced from CBELSA/TAPS Collaboration data of meson transparency in complex nuclei (${\Gamma }^{*}\simeq 30$ MeV/c${}^2$) is approximately 5 times lower than the value obtained with recent theoretical models and consistent with an in-medium total $\omega N$ cross section within 25–30 mb for an average meson momentum of 1.1 GeV/c . The momentum-dependent transparency ratios suggest an elastic/total cross-section ratio around 40$\%$. For the case of CLAS Collaboration data a much higher width is deduced $({\Gamma }^{*}\gtrsim 120$ MeV/c${}^2),$ with the MCMC model providing a consistent interpretation of the data, assuming a much higher meson absorption (${\sigma }_{\omega N}^{*}\gtrsim 100$ mb) for $p_{\omega }\sim 1.7$ GeV/c.

We investigate the linear-chain structures in highly excited states of ${}^{14}$C using a generalized molecular-orbital model, by which we incorporate an asymmetric configuration of three $\alpha$ clusters in the linear-chain states. By applying this model to the ${}^{14}$C system, we study the ${}^{10}\text{Be}+\alpha$ correlation in the linear-chain state of ${}^{14}$C. To clarify the origin of the ${}^{10}\text{Be}+\alpha$ correlation in the ${}^{14}$C linear-chain state, we analyze linear $3\alpha$ and $3\alpha +n$ systems in a similar way. We find that a linear $3\alpha$ system prefers the asymmetric $2\alpha +\alpha$ configuration, whose origin is the many-body correlation incorporated by the parity projection. This configuration causes an asymmetric mean field for two valence neutrons, which induces the concentration of valence neutron wave functions around the correlating 2$\alpha$. A linear-chain structure of ${}^{16}$C is also discussed.

A theoretical method for estimates of a width of “true” four-nucleon decays is developed. Several candidate isotopes to possess this property are considered. Our lifetime estimates compare one-neutron, true two-neutron, and true four-neutron emissions at similar conditions. Prospects of experimental search for two-neutron, four-proton, and four-neutron radioactivity are discussed.

The single-neutron properties of the $N=83$ nucleus ${}^{137}$Xe have been studied using the ${}^{136}$Xe($d$,$p$) reaction in inverse kinematics at a beam energy of 10 MeV/u. The helical-orbit spectrometer, HELIOS, at Argonne National Laboratory was used to analyze the outgoing protons, achieving an excitation-energy resolution of ∼100 keV. Extraction of absolute cross sections, angular distributions, and spectroscopic factors has led to a more complete understanding of the single-neutron strength in ${}^{137}$Xe. In particular, the centroids of the $\nu h_{9/2}$ and $\nu i_{13/2}$ strengths appear to evolve through the $N=83$ isotones in a manner consistent with the action of the tensor force.

The low-lying electric dipole ($E1$) strength in the semimagic nucleus ${}^{136}$Xe has been measured, which finalizes the systematic survey to investigate the so-called pygmy dipole resonance (PDR) in all stable even $N=82$ isotones with the method of nuclear resonance fluorescence using real photons in the entrance channel. In all cases, a fragmented resonance-like structure of $E1$ strength is observed in the energy region 5–8 MeV. An analysis of the fragmentation of the strength reveals that the degree of fragmentation decreases toward the proton-deficient isotones, while the total integrated strength increases, indicating a dependence of the total strength on the neutron-to-proton ratio. The experimental results are compared to microscopic calculations within the quasiparticle phonon model. The calculation includes complex configurations of up to three phonons and is able to reproduce also the fragmentation of the $E1$ strength, which allows us to draw conclusions on the damping of the PDR. Calculations and experimental data are in good agreement on the degree of fragmentation and also on the integrated strength if the sensitivity limit of the experiments is taken into account.

An analysis of results of the ${}^{30}$Mg($t$,$p$) ${}^{32}$Mg reaction demonstrates that the ground state is the normal state and the excited 0${}^{+}$ state is the intruder, contrary to popular belief. Additional experiments are suggested.

We study the evolution of the $(e,e^{\prime }p)$ cross section on nuclei with increasing asymmetry between the number of neutrons and protons. The calculations are done within the framework of the distorted-wave impulse approximation, by adopting nonrelativistic and relativistic models. We compare the results obtained with three different approaches based on the mean-field description for the proton bound-state wave function. In the nonrelativistic model phenomenological Woods-Saxon and Hartree-Fock wave functions are used; in the relativistic model the wave functions are solutions of Dirac-Hartree equations. The models are first tested against experimental data on ${}^{16}$O, ${}^{40}$Ca, and ${}^{48}$Ca nuclei, and then they are applied to calculate $(e,e^{\prime }p)$ cross sections for a set of spherical calcium and oxygen isotopes. From the comparison of the results obtained for the various isotopes we can infer information about the dependence of the various ingredients of the models on the neutron to proton asymmetry.

The ${}^{14}\mathrm{C}(n,\gamma ){}^{15}\mathrm{C}$ reaction plays an important role in inhomogeneous big bang models. In Timofeyuk et al. [Phys. Rev. Lett. 96, 162501 (2006)] it was shown that the ${}^{14}\mathrm{C}(n,\gamma ){}^{15}\mathrm{C}$ radiative capture at astrophysically relevant energies is a peripheral reaction, i.e., the overall normalization of its cross section is determined by the asymptotic normalization coefficient (ANC) for ${}^{15}\mathrm{C}\to {}^{14}\mathrm{C}+n$. Here we present new measurements of the ${}^{14}\mathrm{C}(d,p){}^{15}\mathrm{C}$ differential cross sections at deuteron incident energy of $17.06$ MeV and the analysis to determine the ANCs for neutron removal from the ground and first excited states of ${}^{15}\mathrm{C}$. The results are compared with previous estimations.

In this paper we study the effect of well-known higher-order corrections to the allowed $\beta$-decay spectrum on the determination of antineutrino spectra resulting from the decays of fission fragments. In particular, we try to estimate the associated theory errors and find that induced currents like weak magnetism may ultimately limit our ability to improve the current accuracy and under certain circumstance could even greatly increase the theoretical errors. We also perform a critical evaluation of the errors associated with our method to extract the antineutrino spectrum using synthetic $\beta$ spectra. It turns out that a fit using only virtual $\beta$ branches with a judicious choice of the effective nuclear charge provides results with a minimal bias. We apply this method to actual data for ${}^{235}$U, ${}^{239}$Pu, and ${}^{241}$Pu and confirm, within errors, recent results, which indicate a net $3\%$ upward shift in energy-averaged antineutrino fluxes. However, we also find significant shape differences which can, in principle, be tested by high-statistics antineutrino data samples.

We study three-hadron azimuthal angular correlations in high-energy proton-proton and central nucleus-nucleus collisions at the BNL Relativistic Heavy Ion Collider (RHIC) and the CERN Large Hadron Collider at midrapidity. We use the leading-order parton matrix elements for $2\to 3$ processes and include the effect of parton energy loss in the quark-gluon plasma using the modified fragmentation function approach. For the case when the produced hadrons have either the same or not too different momenta, we observe two away-side peaks at $2\pi /3$ and $4\pi /3$. We consider the dependence of the angular correlations on energy loss parameters that have been used in studies of single inclusive hadron production at RHIC. Our results on the angular dependence of the cross section agree well with preliminary data by the PHENIX Collaboration. We comment on the possible contribution of $2\to 3$ processes to dihadron angular correlations and how a comparison of the two processes may help characterize the plasma further.

Using updated gluon distributions from global fits to data, we investigate the sensitivity of direct photoproduction of heavy quarks and exclusive production of vector mesons to varying strength of gluon modifications. Implications of using these processes for constraining nuclear gluon distributions are discussed.

The so-called number of hadron-nucleus collisions $n_{\mathrm{coll}}\left(b\right)$ at impact parameter $b$ and its integral value $N_{\mathrm{coll}}$, which are used to normalize the measured fractional cross section of a hard process, are calculated within the Glauber-Gribov theory, including the effects of nucleon short-range correlations. The Gribov inelastic shadowing corrections are summed to all orders by employing the dipole representation. Numerical calculations are performed at the energies of the BNL Relativistic Heavy Ion Collider (RHIC) and CERN Large Hadron Collider (LHC). We found that whereas the Gribov corrections generally increase the value of $N_{\mathrm{coll}}$, the inclusion of nucleon correlations, acting in the opposite directions, decreases it by a comparable amount. The interplay of the two effects varies with the value of the impact parameter.

The low-lying one-quasiparticle states are studied in the isotonic chains with $N=147$, 149, 151, 153, and 155 within the microscopic-macroscopic and self-consistent approaches. The energies of one-quasiparticle states change rather smoothly in the isotonic chains if there is no cross of the proton subshell. The $\alpha$-decay schemes of several nuclei are suggested. The isomeric states in the odd isotopes of Fm and No are discussed.

We propose a phenomenological QCD sum rule with an explicit diquark field to investigate the essential ingredients inside the hadrons. By introducing the mass $m_{\phi }$ and the condensate $\langle {\phi }^2\rangle$ for the diquark field as parameters in the model, we find that the sum rule works well for $\Lambda$, ${\Lambda }_c$, and ${\Lambda }_b$. This implies that these $\Lambda$ baryons can be represented by a diquark and a quark configuration. We also find that there is a duality relation among the parameters ($m_{\phi },\langle {\phi }^2\rangle$) for which the sum rule is equally good. In the limit when $\langle {\phi }^2\rangle =0$, we find $m_{\phi }=400$ MeV, which can be thought of as the constituent diquark mass.

We measured the ${}^{12}\mathrm{C}{(p,p^{\prime })}^{12}{\mathrm{C}}^{*}$ reaction at 25 MeV at the three laboratory angles of 20°, 35°, and 45°. The measured spectra support recent evidence for a new broad $2_2^{+}$ state at 9.6 MeV in ${}^{12}\mathrm{C}$, but do not support the claim for such a broad state at 11.1 MeV.

We report precision ${}^1$H$(e,e^{\prime }{\pi }^{+})n$ measurements in the $\Delta \left(1232\right)$ resonance at $Q^2=0.127$(GeV/$c$)${}^2$ obtained at the MIT-Bates out-of-plane scattering facility. These are the lowest, but nonzero, $Q^2$ measurements in the ${\pi }^{+}$ channel. The data offer tests of the theoretical calculations, particularly of the background amplitude contributions. The chiral effective field theory and Sato-Lee model calculations are not in agreement with this experiment.

A set of relativistic mean-field models is constructed, which includes the Hartree and Hartree-Fock (HF) approximations accounting for the exchange of isoscalar and isovector mesons as well as the pion. Density-dependent coupling functions are determined to reproduce the components of the nucleon self-energy at the Fermi surface, obtained within the Dirac-Brueckner-HF (DBHF) approach by using a realistic nucleon-nucleon interaction. It is investigated to which extent the various mean-field models can reproduce the DBHF results for the momentum dependence of the self-energies and the total energy of infinite matter. Also, the mean-field models are used to evaluate the bulk properties of spherical closed-shell nuclei. We find that the HF model, which allows for the exchange of $\sigma ,\omega ,\rho$, and $\delta$ mesons and pions, yields the best reproduction of the DBHF results in infinite matter and also provides a good description of the properties of finite nuclei without any adjustment of parameters.

The phase structure of symmetric nuclear matter in the extended Nambu-Jona-Lasinio (ENJL) model is studied by means of the effective potential in the one-loop approximation. It is found that chiral symmetry gets restored at high nuclear density and a typical first-order phase transition of the liquid-gas transition occurs at zero temperature, $T=0$, which weakens as $T$ grows and eventually ends up with a second-order critical point at $T=20$ MeV. This phase transition scenario is confirmed by investigating the evolution of the effective potential versus the effective nucleon mass and the equation of state.