The role of the symmetry energy and the neutron-matter stiffness on the tidal deformability of a cold nonaccreted neutron star is studied using a set of unified equations of state. Based on the nuclear energy-density functional theory, these equations of state provide a thermodynamically consistent treatment of all regions of the star and were calculated using functionals that were precision fitted to experimental and theoretical nuclear data. Predictions are compared to constraints inferred from the recent detection of the gravitational-wave signal GW170817 from a binary neutron-star merger and from observations of the electromagnetic counterparts.

Recently, Allmond and Wood [J. M. Allmond and J. L. Wood, Phys. Lett. B 767, 226 (2017)] were able to extract the three moments of inertia ${\mathfrak{I}}_k$ of a dozen of superfluid triaxial nuclei from experimental data. The observed dependence of the ${\mathfrak{I}}_k$ on the deformation parameters is rather smooth. Here we show that these moments of inertia can be surprisingly well explained by a semiclassical cranked Hartree-Fock-Bogoliubov (HFB) calculation in which the velocity field is a simple superposition of rigid and irrotational flows.

The macroscopic-microscopic finite-range droplet model is combined with a particle-rotor coupling model in order to systematically describe low-energy spectra of odd-odd nuclei. The odd proton and neutron are allowed to interact through effective nuclear forces representing the residual neutron-proton interaction. In particular, ground-state spins and parities are calculated and compared to data, where all 268 axially symmetric nuclei which have reliable spin and parity assignments in the Nubase 2016 database are considered. Using a residual neutron-proton interaction composed of both central and tensor terms the agreement with experimental ground-state spins and parities reaches 41% for spherical nuclei and 31% for deformed nuclei. The model is applied to study possible $\alpha$-decay chains in superdeformed odd-odd nuclei, and $Q_{\alpha }$ values are calculated considering favored decay-paths as compared to ground-state paths.

The National Ignition Facility (NIF) provides the opportunity to study nuclear reactions under controlled conditions at high temperatures and pressures at a level never before achieved. However, the timescale of the deuterium-tritium (DT) implosion is only a few nanoseconds, making data collection and diagnostics very challenging. One method that has been proposed for obtaining additional information about the conditions of the implosion is to activate a dopant material using the $\alpha$ particles produced from the DT fuel as a diagnostic. The yield of the activated material can give a measure of the mixing that occurs in the capsule. One of the reactions that has been proposed is ${}^{10}\mathrm{B}(\alpha ,n){}^{13}\mathrm{N}$ as it produces a radioactive reactant product with a convenient half-life of $\approx 10\min$. Although this reaction has several advantages for the application at hand, it has not seen much study in the present literature, resulting in large uncertainties in the cross section. Furthermore, for the current application, the cross section must be well characterized. With this motivation, the ${}^{10}\mathrm{B}(\alpha ,n){}^{13}\mathrm{N}$ cross section has been remeasured for $2.2<E_{\alpha }<4.9\mathrm{MeV}$ with the angle-integrated ground-state cross section reported for the first time. The present results, combined with previous measurements, allow for a determination of the cross section to a significantly higher degree of accuracy and precision than obtained previously and are shown to be consistent with thick-target measurements. Preliminary calculations are performed to test the feasibility of this reaction as a diagnostic for a NIF implosion.

A microscopic analysis of the optical potentials (OPs) and cross sections of quasielastic scattering of ${}^{12,14}\mathrm{Be}$ on ${}^{12}\mathrm{C}$ at 56 MeV/nucleon and on protons at an energy near 700 MeV is carried out. For lower energy scattering the real part of the OP is calculated by using the double-folding procedure accounting for the antisymmetrization effects, while the imaginary part is obtained on the basis of the high-energy approximation (HEA). The HEA is also applied to the calculations of both real and imaginary OPs when solving the relativistic equation for the high-energy proton-nucleus elastic scattering. The neutron and proton density distributions computed in different microscopic models for ${}^{12}\mathrm{Be}$ and ${}^{14}\mathrm{Be}$ are used. In the present hybrid model of the optical potential the only free parameters are the depths of the real and imaginary parts of the OP obtained by fitting the experimental data. The role of the inelastic scattering channel to the first excited $2^{+}$ and $3^{-}$ states in ${}^{12}\mathrm{C}$ when calculating the quasielastic cross sections, as well as the modified density of the ${}^{12}\mathrm{C}$ target accounting for the surface effects, are studied. In addition, the cluster model, in which ${}^{14}\mathrm{Be}$ consists of a $2n$ halo and the ${}^{12}\mathrm{Be}$ core, is applied to calculate the cross sections of diffraction breakup and stripping reactions in ${}^{14}\mathrm{Be}+{}^{12}\mathrm{C}$ scattering and longitudinal momentum distributions of ${}^{12}\mathrm{Be}$ fragments at an energy of 56 MeV/nucleon. A good agreement of the theoretical results with the available experimental data of both quasielstic scattering and breakup processes is obtained.

The elastic scattering of the radioactive proton-rich carbon isotope ${}^{10}\mathrm{C}$ has been investigated. A full differential angular distribution for the elastic scattering of ${}^{10}\mathrm{C}$ on a ${}^{58}\mathrm{Ni}$ target has been measured at $E_{\mathrm{Lab}}=35.3$ MeV, which is just above the Coulomb barrier for this system ($V_B=27$ MeV). The obtained angular distribution was analyzed in terms of coupled-channels, coupled-reaction-channels, and continuum-discretized coupled-channels calculations. In the coupled-channels calculation, several inelastic transitions of the target and the first ($2^{+}$) excited state of the ${}^{10}\mathrm{C}$ projectile were considered. The coupling to the first ($2^{+}$) excited state of ${}^{10}\mathrm{C}$ was shown to be very important to describe the rising of the cross section at backward angles. We also performed an analysis with the continuum-discretized coupled channels, considering the ${}^9\mathrm{B}+p$ and ${}^6\mathrm{Be}+\alpha$ channels, which indicated a strong cluster configuration for the ${}^{10}\mathrm{C}$ projectile.

We consider causal higher order theories of relativistic viscous hydrodynamics in the limit of one-dimensional boost-invariant expansion and study the associated dynamical attractor. We obtain evolution equations for the inverse Reynolds number as a function of Knudsen number. The solutions of these equations exhibit attractor behavior which we analyze in terms of Lyapunov exponents using several different techniques. We compare the attractors of the second-order Müller-Israel-Stewart (MIS), transient Denicol-Niemi-Molnar-Rischke (DNMR), and third-order theories with the exact solution of the Boltzmann equation in the relaxation-time approximation. It is shown that for Bjorken flow the third-order theory provides a better approximation to the exact kinetic theory attractor than both MIS and DNMR theories. For three different choices of the time dependence of the shear relaxation rate we find analytical solutions for the energy density and shear stress and use these to study the attractors analytically. By studying these analytical solutions at both small and large Knudsen numbers we characterize and uniquely determine the attractors and Lyapunov exponents. While for small Knudsen numbers the approach to the attractor is exponential, strong power-law decay of deviations from the attractor and rapid loss of initial state memory are found even for large Knudsen numbers. Implications for the applicability of hydrodynamics in far-off-equilibrium situations are discussed.

The rotation-induced inhomogeneous problem is nontrivial and inevitable. In this paper a generic framework is developed to investigate the inhomogeneous condensate in a system of fermions under the presence of rotation. It is a self-consistent method based on a set of relativistic Bogoliubov-de Gennes equations solved with typical iteration algorithm. Taking the chiral condensate as an example we study rotational effects numerically and discover two inhomogeneous effects: the local rotational suppression effect and centrifugal effect. They may have significant impact on the phase structure of various kinds of matter. Several systems in different physics branches are discussed in the paper.

The first CLAS12 experiments will provide high-precision data on inclusive electron scattering observables at a photon virtuality $Q^2$ ranging from 0.05 to $12{\mathrm{GeV}}^2$ and center-of-mass energies $W$ up to 4 GeV. In view of this endeavor, we present the modeling of the resonant contributions to the inclusive electron scattering observables. As input, we use the existing CLAS electrocoupling results obtained from exclusive meson electroproduction data off protons, and evaluate for the first time the resonant contributions based on the experimental results on the nucleon resonance electroexcitation. The uncertainties are given by the data and duly propagated through a Monte Carlo approach. In this way, we obtain estimates for the resonant contributions, important for insight into the nucleon parton distributions in the resonance region and for the studies of quark-hadron duality.

We present a study of the $\tau$ polarization in charged-current quasielastic (anti)neutrino-nucleus scattering. The spectral function formalism is used to compute the differential cross section and the polarization components for several kinematical setups, relevant for neutrino-oscillation experiments. The effects of the nuclear corrections in these observables are investigated by comparing the results obtained using two different realistic spectral functions, with those deduced from the relativistic global Fermi gas model, where only statistical correlations are accounted for. We show that the spectral functions, although they play an important role when predicting the differential cross sections, produce much less visible effects on the polarization components of the outgoing $\tau$.

Nuclear clustering plays an important role, especially in the dynamics of light nuclei. The importance of the emergence of the nuclear clustering was discussed in the recent measurement of the photoabsorption cross sections as it offered the possibility of the coexistence of various excitation modes which are closely related to the nuclear clustering. To understand the excitation mechanism, we study the electric-dipole ($E1$) responses of ${}^6\mathrm{Li}$ with a fully microscopic six-body calculation. The ground-state wave function is accurately described with a superposition of correlated Gaussian (CG) functions with the aid of the stochastic variational method. The final-state wave functions are also expressed by a number of the CG functions including important configurations to describe the six-body continuum states excited by the $E1$ field. We found that the out-of-phase transitions occur due to the oscillations of the valence nucleons against the ${}^4\mathrm{He}$ cluster at the low energies around 10 MeV indicating “soft” giant-dipole-resonance (GDR)-type excitations, which are very unique in the ${}^6\mathrm{Li}$ system but could be found in other nuclear systems. At the high energies beyond $\sim 30$ MeV typical GDR-type transitions occur. The ${}^3\mathrm{He}-{}^3\mathrm{H}$ clustering plays an important role to the GDR phenomena in the intermediate-energy regions around 20 MeV.

A set of differential cross section of the three-body ${}^2\mathrm{H}(d,dp)n$ breakup reaction at 160-MeV deuteron beam energy is presented for 147 configurations covering a wide kinematical region around quasifree scattering. The experiment was performed at KVI in Groningen, the Netherlands, using the BINA detector. The cross-section data have been normalized to the ${}^2\mathrm{H}(d,d){}^2\mathrm{H}$ elastic-scattering cross section. The data are compared to the results of recent single-scattering approximation (SSA) calculations for three-cluster breakup in deuteron-deuteron collisions. This comparison shows that SSA provides the correct order of magnitude of the cross sections. The studied energy is probably too low to meet the SSA assumptions which prevents better accuracy of the description.

A new method is proposed for extrapolation of elastic-scattering data to the negative-energy region for a short-range interaction. The method is based on the analytic approximation of the modulus-squared of the partial-wave scattering amplitude and can serve as an alternative to the traditional one based on continuation of the effective-range function. The new method has been applied to determine the asymptotic normalization coefficients for the ${}^{17}\mathrm{O}$ and ${}^{13}\mathrm{C}$ nuclei in the $n+{}^{16}\mathrm{O}$ and $n+{}^{12}\mathrm{C}$ channels, respectively. The asymptotic normalization coefficients obtained by the new method are compared with the ones obtained in the effective-range function approach.

I have used a simple model to estimate the relative populations expected for the ground state (g.s.) and three excited states of ${}^{11}\mathrm{O}$ in 2n removal from ${}^{13}\mathrm{O}$. Results are ratios exc./g.s. of at most a few percent for each excited state, compared to ratios near unity suggested in a recent experiment involving ${}^{11}\mathrm{O}$.

The quark-meson-coupling (QMC) model self-consistently relates the dynamics of the internal quark structure of a hadron to the relativistic mean fields arising in nuclear matter. It offers a natural explanation to some open questions in nuclear theory, including the origin of many-body nuclear forces and their saturation, the spin-orbit interaction, and properties of hadronic matter at a wide range of densities. The QMC energy density functionals QMC-I and $\mathrm{QMC}\pi$-I have been successfully applied to calculate ground state observables of finite nuclei in the Hartree-Fock $+$ BCS approximation, as well as to predict properties of dense nuclear matter and cold nonrotating neutron stars. Here we report the latest development of the model, $\mathrm{QMC}\pi$-II, which includes higher order terms in density in the expansion of the relativistic energy-density functional, as well as the self-interaction of the $\sigma$ meson. A derivative-free optimization algorithm has been employed to determine a new set of the model parameters and their statistics, including errors and correlations. $\mathrm{QMC}\pi$-II predictions for a wide range of properties of even-even nuclei across the nuclear chart, with fewer adjustable parameters, are comparable with other models. The nuclear incompressibility is significantly reduced in this version, leading to a description of giant monopole resonances which is consistent with experimental data.

Fission fragment mass distributions have been measured for relatively neutron-deficient compound nuclei, ${}^{188}\mathrm{Pt}$ and ${}^{190}\mathrm{Pt}$, formed in the fusion reactions, ${}^{28}\mathrm{Si}+{}^{160}\mathrm{Gd}$ and ${}^{12}\mathrm{C}+{}^{178}\mathrm{Hf}$, respectively. The data were obtained for a similar initial excitation energy range of 49–68 MeV for both the systems. The fragment mass distributions for both the Pt isotopes were found to be single peaked and no appreciable change in the mass symmetry was observed throughout the measured excitation energy range, for both the reactions. However, relatively broader mass distributions observed in the fission of ${}^{188}\mathrm{Pt}$ in the studied energy domain indicates the presence of fission events originating from a nonequilibrated source as well. This signifies that the mass equilibrium has not been fully achieved in the ${}^{28}\mathrm{Si}+{}^{160}\mathrm{Gd}$ system as compared to the ${}^{12}\mathrm{C}+{}^{178}\mathrm{Hf}$ system, indicating the presence of quasifission events in the former reaction.

We use the available experimental Gamow-Teller ${\beta }^{-}$ and ${\beta }^{+}$/EC (electron-capture) decay rates between $0^{+}$ and $1^{+}$ ground states in neighboring even-even and odd-odd nuclei, combined with $2\nu \beta \beta$ half-lives, to analyze the influence of the nuclear environment on the weak axial-vector strength $g_{\mathrm{A}}$. For this purpose, the proton-neutron deformed quasiparticle random-phase approximation (pn-dQRPA), with schematic dipole residual interaction is employed. The Hamiltonian contains particle-hole (ph) and particle-particle (pp) channels with mass-dependent strengths. In deriving the equations of motion we use a self-consistent procedure in terms of a single-particle basis with projected angular momentum provided by the diagonalization of a spherical mean field plus the quadrupole-quadrupole interaction. Our analysis evidenced a quenched average effective value $\langle g_{\mathrm{A}}\rangle \approx 0.7$ with a root-mean-square deviation of $\sigma \approx 0.3$ for transitions from even-even emitters and $\sigma \approx 0.6$ for transitions from odd-odd emitters.

Numerous scientific fields including astrophysics, nuclear power, and nuclear forensics require a knowledge of basic nuclear properties for large numbers of short-lived, radioactive isotopes far removed from stable nuclei. Neutron-capture cross sections are one such piece of nuclear data where direct measurements are not possible and theoretical predictions can vary by orders of magnitude. A recently developed indirect technique for inferring neutron capture rates, the $\beta$-Oslo method, has been introduced but not compared against a known, directly measured neutron capture cross section. To provide this benchmark, two indirect methods based on $\beta$ decay and charged-particle reactions were used to extract the nuclear level density and $\gamma$-ray strength function of ${}^{51}\mathrm{Ti}$. The nuclear level density and $\gamma$-ray strength function from the two data sets were found to be equivalent and were used to extract the neutron capture cross section of ${}^{50}\mathrm{Ti}$ which agrees with previous direct measurements at high neutron energies. The results demonstrate the validity of the $\beta$-Oslo method for extracting neutron capture cross sections of short-lived nuclei and provide a sufficiently small uncertainty to be used in various applications.

We extend our Monte Carlo algorithm for generating global configurations in nuclei to include different spatial distributions of protons and neutrons in heavy nuclei, taking into account the difference of spatial correlations between two protons, two neutrons, and proton-neutron pairs. We generate configurations for ${}^{48}\mathrm{Ca}$ and ${}^{208}\mathrm{Pb}$ neutron-rich nuclei, which can be used in general-purpose high-energy $A(e,e^{\prime }p)$, $p\text{−}A$, and $A\text{−}A$ event generators. As an application of lead configurations, we developed an algorithm for proton-heavy nucleus collisions at the CERN Large Hadron Collider for final states with a hard interaction in the channels where cross sections for $p\text{−}p$ and $p\text{−}n$ scattering differ. Soft interactions are taken into account in the color fluctuation extension of the Glauber algorithm, taking into account the inherently different transverse geometry of soft and hard $p\text{−}N$ collisions. We use the new event generator to test an interesting observation of Paukkunen [Phys. Lett. B 745, 73 (2015)] that the ratio of ${\mathrm{W}}^{\pm }$ production rates in $p$-Pb collisions should significantly deviate from the inclusive value for peripheral collisions due to the presence of a neutron skin. We qualitatively confirm expectation of Paukkunen, although, for a realistic centrality trigger, we find the effect to be a factor of 2 smaller than the original estimate.

We compute the correction to the energy loss of a hard parton due to short separation distances between the creation of the particle and the in-medium scattering center that stimulates bremsstrahlung radiation to first order in opacity. In deriving the result we make full use of the large-formation-time assumption, which results in a significant reduction of the number of diagrams contributing to the small-separation-distance correction. An asymptotic analysis of our small-separation-distance correction term finds that the correction dominates at large $\sim 100$ GeV parent parton energies, scales like $L$ with the size of the system for small $L$ but like $L^0$ at larger $L$, and breaks color triviality. An extensive numerical investigation of the correction term confirms the aforementioned analytic findings, reveals that the correction term does not go to zero for large $L$, finds that the correction is sensitive to the mass of the parent parton, and shows a crucial dependence of the energy loss on a proper treatment of the physics of separation distances on the order of the Debye screening length. However, on examination, we have found the large-formation-time approximation to be invalid for much of the phase space of the emitted radiation, implying a need to investigate the sensitivity of jet quenching results from relaxing this approximation. Our result constitutes an important step toward understanding partonic energy loss in small colliding systems.