Excited states in ${}^{14}\mathrm{O}$ have been investigated both experimentally and theoretically. Experimentally, these states were produced via neutron-knockout reactions with a fast ${}^{15}\mathrm{O}$ beam and the invariant-mass technique was employed to isolate the $1p$ and $2p$ decay channels and determine their branching ratios. The spectrum of excited states was also calculated with the shell model embedded in the continuum that treats bound and scattering states in a unified model. By comparing energies, widths, and decay branching patterns, spin and parity assignments for all experimentally observed levels below 8 MeV are made. This includes the location of the second $2^{+}$ state that we find is in near degeneracy with the third $0^{+}$ state. An interesting case of sequential $2p$ decay through a pair of degenerate ${}^{13}\mathrm{N}$ excited states with opposite parities was found where the interference between the two sequential decay pathways produces an unusual relative-angle distribution between the emitted protons.

Electron capture ($\beta$-decay) rates of ${}^7\mathrm{Be}$ and ${}^7\mathrm{Be}_2$ encapsulated in ${\mathrm{C}}_{70}$ have been estimated by calculating the electron density $\rho \left(0\right)$ at the ${}^7\mathrm{Be}$ nucleus and comparing it with $\rho \left(0\right)$ and experimental $\beta$-decay rates of ${}^7\mathrm{Be}$ inside another fullerene—${\mathrm{C}}_{60}$. For that the endohedral fullerenes ${}^7\mathrm{Be}@{\mathrm{C}}_{70}$ and ${}^7\mathrm{Be}_2@{\mathrm{C}}_{70}$ have been examined by means of the ab initio approach using the Hartree-Fock method with the the second order Møller-Plesset perturbation theory accounting for the Van der Waals foces. Our calculations indicate that the ${}^7\mathrm{Be}_2@{\mathrm{C}}_{70}$ complex is stable with the binding energy of 1.3 eV and the ${}^7\mathrm{Be}$ dimer bond length 2.30 Å. It has been found that $\rho \left(0\right)$ is practically the same in ${}^7\mathrm{Be}@{\mathrm{C}}_{70}$ and ${}^7\mathrm{Be}_2@{\mathrm{C}}_{70}$, but larger than in an isolated ${}^7\mathrm{Be}$ atom. The increase of $\rho \left(0\right)$ however is smaller than in ${}^7\mathrm{Be}@{\mathrm{C}}_{60}$. We also discuss in detail the mechanism underlying the increase of $\rho \left(0\right)$ and consequently the decrease of the decay rate in ${}^7\mathrm{Be}@{\mathrm{C}}_{70}$ in comparison with the isolated ${}^7\mathrm{Be}$ atom.

Background: Proton-induced nucleon knockout $(p,pN)$ reactions have been successfully used to study the single-particle nature of stable nuclei in normal kinematics with the distorted-wave impulse approximation (DWIA) framework. Recently, these reactions have been applied to rare-isotope beams at intermediate energies in inverse kinematics to study the quenching of spectroscopic factors.

Purpose: Our goal is to investigate the effects of various corrections and uncertainties within the standard DWIA formalism on the $(p,pN)$ cross sections. The consistency of the extracted reduction factors between DWIA and other methods is also evaluated.

Method: We analyze the $(p,2p)$ and $(p,pn)$ reaction data measured at the ${\mathrm{R}}^3\mathrm{B}$-LAND setup at GSI for carbon, nitrogen, and oxygen isotopes in the incident energy range of 300–450 MeV/u. Cross sections and reduction factors are calculated by using the DWIA method. The transverse momentum distribution of the ${}^{12}\mathrm{C}(p,2p){}^{11}\mathrm{B}$ reaction is also investigated.

Results: We have found that including the nonlocality corrections and the Møller factor affects the cross sections considerably. The proton-neutron asymmetry dependence of reduction factors extracted by the DWIA calculation is very weak and consistent with those given by other reaction methods and ab initio structure calculations.

Conclusions: The results found in this work provide a detailed investigation of the DWIA method for $(p,pN)$ reactions at intermediate energies. They also suggest that some higher-order effects, which is essential for an accurate cross-section description at large recoil momentum, is missing in the current DWIA and other reaction models.

We propose a microscopic description for the polarization from the first principle through the spin-orbit coupling in particle collisions. It is based on scatterings of particles as wave packets, an effective method to deal with particle scatterings at specified impact parameters. The polarization is then the consequence of particle collisions in a nonequilibrium state of spins. The spin-vorticity coupling naturally emerges from the spin orbit one encoded in polarized scattering amplitudes of collisional integrals when one assumes local equilibrium in momentum but not in spin.

Two new bands built on the two-quasiparticle $\pi {\left(h_{11/2}\right)}^2$ configuration of the even-even nucleus ${}^{130}\mathrm{Ba}$ are investigated using constrained triaxial covariant density functional theory combined with quantum particle rotor model calculations. The energy difference between the two bands, as well as the available electromagnetic transition probabilities $B{\left(M1\right)}_{\mathrm{out}}/B{\left(E2\right)}_{\mathrm{in}}$ and $B{\left(E2\right)}_{\mathrm{out}}/B{\left(E2\right)}_{\mathrm{in}}$, are well reproduced. The analysis of the angular momentum geometry reveals that the higher band represents transverse wobbling motion of a two-quasiparticle configuration. This is the first example of two-quasiparticle wobbling bands in an even-even nucleus.

We present a lattice method for determining scattering phase shifts and mixing angles for the case of an arbitrary number of coupled channels. Previous nuclear lattice effective field theory simulations were restricted to mixing of up to two partial waves for scattering of two spin-$1/2$ particles, which is insufficient for analyzing nucleon-nucleus or nucleus-nucleus scattering processes. In the proposed method, the phase shifts and mixing angles are extracted from the radial wave functions obtained by projecting the three-dimensional lattice Hamiltonian onto the partial wave basis. We use a spherical wall potential as a boundary condition along with a channel-mixing auxiliary potential to construct the full-rank $S$ matrix. Our method can be applied to particles with any spin, but we focus here on scattering of two spin-1 bosons involving up to four coupled channels. For a considered test potential, the phase shifts and mixing angles extracted on the lattice are shown to agree with the ones calculated by solving the Schrödinger equation in the continuum.

We present new experimental angular distributions for the elastic scattering of ${}^6\mathrm{Li}+{}^{120}\mathrm{Sn}$ at three bombarding energies. We include these data in a wide systematic involving the elastic scattering of ${}^{4,6}\mathrm{He},{}^7\mathrm{Li}$, ${}^9\mathrm{Be},{}^{10}\mathrm{B}$, and ${}^{16,18}\mathrm{O}$ projectiles on the same target at energies around the respective Coulomb barriers. Considering this data set, we report on optical model analyses based on the double-folding São Paulo potential. Within this approach, we study the sensitivity of the data fit to different models for the nuclear matter densities and to variations in the optical potential strengths.

Thermodynamic properties of systems with repulsive interactions are considered in the grand-canonical ensemble. The analytic structure of the excluded-volume model in the complex plane of the system chemical potential (fugacity) is elaborated, based on the fact that the pressure function can be given in terms of the Lambert $W$ function. Even though the excluded-volume model has no phase transitions at real values of the chemical potential, it does exhibit a branch cut singularity in the complex plane, thus limiting the convergence range of the Taylor expansion in the chemical potential. Close similarities to analytic properties of the other models with repulsive interactions, such as a cluster expansion model, the mean-field model, and the ideal Fermi gas model, are pointed out. As an example, repulsive baryonic interactions in a hadron gas, with a focus on the fugacity/virial and Taylor expansion methods used in lattice QCD, are presented. The asymptotic behavior of the Fourier expansion coefficients in these various models suggests that the singular part of net baryonic density can to leading order be universally expressed in terms of polylogarithms.

The dependence of the nuclear temperature on the source neutron-proton ($N/Z$) asymmetry is experimentally investigated with the intermediate mass fragments (IMFs) generated from thirteen reaction systems with different $N/Z$ asymmetries, ${}^{64}\mathrm{Zn}$ on ${}^{112}\mathrm{Sn}$ and ${}^{70}\mathrm{Zn}, {}^{64}\mathrm{Ni}$ on ${}^{112,124}\mathrm{Sn}, {}^{58,64}\mathrm{Ni}, {}^{197}\mathrm{Au}, {}^{232}\mathrm{Th}$ at 40 MeV/nucleon. The apparent source temperatures for these systems are determined from the measured IMF yields from the intermediate velocity sources using eight carbon-related double isotope ratio thermometers. A rather weak $N/Z$ asymmetry dependence of the source temperature is qualitatively inferred from the extracted $N/Z$ asymmetry dependence of the apparent temperature and that of the relative temperature change by the sequential decay effects with the help of the theoretical simulations. The present result is compared with those from other available experiments.

We use experimentally measured identified particle spectra and Hanbury Brown-Twiss radii to determine the entropy per unit rapidity $dS/dy$ produced in $\sqrt{s}=7\mathrm{TeV} \mathit{pp}$ and $\sqrt{s_{\mathrm{NN}}}=2.76\mathrm{TeV}$ Pb-Pb collisions. We find that $dS/dy=11335\pm 1188$ in 0%–10% Pb-Pb, $dS/dy=135.7\pm 17.9$ in high-multiplicity $\mathit{pp}$, and $dS/dy=37.8\pm 3.7$ in minimum bias $\mathit{pp}$ collisions and compare the corresponding entropy per charged particle $(dS/dy)/(d{N}_{\mathrm{ch}}/dy)$ to predictions of statistical models. Finally, we use the quantum chromodynamics kinetic theory pre-equilibrium and viscous hydrodynamics to model entropy production in the collision and reconstruct the average temperature profile at ${\tau }_0\approx 1\mathrm{fm}/c$ for high-multiplicity $\mathit{pp}$ and Pb-Pb collisions.

The ${}^{12}\mathrm{C}(\alpha ,\gamma ){}^{16}\mathrm{O}$ reaction, an important component of stellar helium burning, has a key role in nuclear astrophysics. It has direct impact on the evolution and final state of massive stars and also influences the elemental abundances resulting from nucleosynthesis in such stars. Providing a reliable estimate for the energy dependence of this reaction at stellar helium burning temperatures has been a longstanding and important goal. In this work, we study the role of potential new measurements of the ${}^{16}\mathrm{O}(e,e^{\prime }\alpha ){}^{12}\mathrm{C}$ reaction in reducing the overall uncertainty. A multilevel $R$-matrix analysis is used to make extrapolations of the astrophysical $S$ factor for the ${}^{12}\mathrm{C}(\alpha ,\gamma ){}^{16}\mathrm{O}$ reaction to the stellar energy of 300 keV. The statistical precision of the $S$-factor extrapolation is determined by performing multiple fits to existing $E1$ and $E2$ ground state capture data, including the impact of possible future measurements of the ${}^{16}\mathrm{O}(e,e^{\prime }\alpha ){}^{12}\mathrm{C}$ reaction. In particular, we consider a proposed MIT experiment that would make use of a high-intensity low-energy electron beam that impinges on a windowless oxygen gas target as a means to determine the total $E1$ and $E2$ cross sections for this reaction.

The Gamow shell model is utilized to describe nuclear observables of the weakly bound and resonance isotonic states of ${}^{16}\mathrm{O}$ at the proton drip-line. It is hereby shown that the presence of continuum coupling leads to complex Coulomb contributions in the spectrum of these isotones. The necessity to include the effects of three-body forces, either by a direct calculation or by adding an $A$ dependence to the nucleon-nucleon interaction, already noticed in other theoretical models, is pointed out. It is also demonstrated that our approach is predictive for reaction observables.

Using the wounded nucleon, quark, and quark-diquark models, we extract the wounded source emission functions from the PHOBOS data for $d+\mathrm{Au}$ collisions at $\sqrt{s_{NN}}=200$ GeV. We apply these functions to compute charged particle multiplicity distributions as functions of pseudorapidity for $p+p, p+\mathrm{Al}, p+\mathrm{Au}, d+\mathrm{Au}, {}^3\mathrm{He}+\mathrm{Au}, \mathrm{Cu}+\mathrm{Cu}, \mathrm{Cu}+\mathrm{Au}, \mathrm{Au}+\mathrm{Au}$, and $\mathrm{U}+\mathrm{U}$ collisions at the same energy and compare them with experimental data from the PHOBOS and PHENIX Collaborations. In symmetric collisions of heavy nuclei, the obtained distributions differ among the tested models. On the other hand, in asymmetric collisions, all three models give essentially the same distributions. The wounded quark-diquark and quark models are in reasonable agreement with data for all the investigated systems.

We present the formalism of linear response theory both at zero and finite temperature in the case of asymmetric nuclear matter excited by an isospin flip probe. The particle-hole interaction is derived from a general Skyrme functional that includes spin-orbit and tensor terms. Response functions are obtained by solving a closed algebraic system of equations. Spin strength functions are analyzed for typical values of density, momentum transfer, asymmetry, and temperature. We evaluate the role of statistical errors related to the uncertainties of the coupling constants of the Skyrme functional and thus determine the confidence interval of the resulting response function.

Individual low-energy $E1$ toroidal and compressional states (TS and CS) produced by the convective nuclear current ${\mathbf{j}}_c$ were recently predicted for ${}^{24}\mathrm{Mg}$ in the framework of quasiparticle random-phase approximation (QRPA) with Skyrme forces. In the present QRPA study with Skyrme parametrization SLy6, we explore in more detail properties of these states [toroidal and compressional responses, current distributions, and transitions probabilities $B(E1K,0^{+}0\to 1^{-}K),B(E3K,0^{+}0\to 3^{-}K)$, and $B(M2K,0^{+}0\to 2^{-}K)$ with $K=0$ and 1] and analyze the possibility to discriminate and identify TS in inelastic electron scattering to back angles. The interplay of the convective ${\mathbf{j}}_c$ and magnetization ${\mathbf{j}}_m$ nuclear currents is thoroughly scrutinized. A two-step scheme for identification of TS in $(e,e^{\prime })$ reaction is proposed. The key element of the scheme is the strong interference of the orbital and spin contributions, resulting in specific features of $E1$ and $M2$ transversal form factors.

Studies of the fragmentation of jets into charged particles in heavy-ion collisions can provide information about the mechanism of jet quenching by the hot and dense QCD matter created in such collisions, the quark-gluon plasma. This paper presents a measurement of the angular distribution of charged particles around the jet axis in $\sqrt{s_{NN}}=5.02$ TeV $\mathrm{Pb}+\mathrm{Pb}$ and pp collisions, using the ATLAS detector at the LHC. The $\mathrm{Pb}+\mathrm{Pb}$ and $pp$ data sets have integrated luminosities of $0.49{\mathrm{nb}}^{-1}$ and $25{\mathrm{pb}}^{-1}$, respectively. The measurement is performed for jets reconstructed with the anti-$k_t$ algorithm with radius parameter $R=0.4$ and is extended to an angular distance of $r=0.8$ from the jet axis. Results are presented as a function of $\mathrm{Pb}+\mathrm{Pb}$ collision centrality and distance from the jet axis for charged particles with transverse momenta in the 1- to 63-GeV range, matched to jets with transverse momenta in the 126- to 316-GeV range and an absolute value of jet rapidity of less than 1.7. Modifications to the measured distributions are quantified by taking a ratio to the measurements in $pp$ collisions. Yields of charged particles with transverse momenta below 4 GeV are observed to be increasingly enhanced as a function of angular distance from the jet axis, reaching a maximum at $r=0.6$. Charged particles with transverse momenta above 4 GeV have an enhanced yield in $\mathrm{Pb}+\mathrm{Pb}$ collisions in the jet core for angular distances up to $r=0.05$ from the jet axis, with a suppression at larger distances.

I discuss the properties of the ${\mathrm{\Lambda }}_c$ baryon in nuclear matter at zero or finite temperature. Starting from the Lagrangian based on the heavy-quark effective theory, I derive the effective Lagrangian for the ${\mathrm{\Lambda }}_c$ baryon existing as an impurity particle. Adopting the one-loop calculation for nucleons, I derive the effective potential as the quantity for measuring the stability of the ${\mathrm{\Lambda }}_c$ baryon in nuclear matter. The parameters in the Lagrangian are fitted to reproduce the scattering length of the nucleon and the ${\mathrm{\Lambda }}_c$ baryon estimated in the lattice QCD simulations and the chiral extrapolations. I present that the ${\mathrm{\Lambda }}_c$ baryon is bound in nuclei with the binding energy of about 20 MeV at normal nuclear-matter density. I discuss the case that the ${\mathrm{\Lambda }}_c$ baryon moves with a constant velocity. I also discuss an increase of the nucleon number density near the ${\mathrm{\Lambda }}_c$ baryon in nuclear matter, and show that the ${\mathrm{\Lambda }}_c$ baryon is a useful probe to research the nuclear systems at high density.

Mutual entrainment effects in cold neutron-proton mixtures are studied in the framework of the self-consistent nuclear energy-density functional theory. Exact expressions for the mass currents, valid for both homogeneous and inhomogeneous systems, are directly derived from the time-dependent Hartree-Fock equations with no further approximation. The equivalence with the Fermi-liquid expression is also demonstrated. Focusing on neutron-star cores, a convenient and simple analytical formulation of the entrainment matrix in terms of the isovector effective mass is found, thus allowing one to relate entrainment phenomena in neutron stars to isovector giant dipole resonances in finite nuclei. Results obtained with different functionals are presented. These include the Brussels-Montreal functionals, for which unified equations of state of neutron stars have been recently calculated.

We report first precision mass measurements of the $1/2^{-}$ isomeric and $9/2^{+}$ ground states of ${}^{101}\mathrm{In}$. The determined isomeric excitation energy continues a smooth trend of odd-$A$ indium isotopes up to the immediate vicinity of $N=50$ magic number. This trend can be confirmed by dedicated shell-model calculations only if the neutron configuration mixing is considered. We find that the single-particle energies are different for different states of the same isotope. The presented configuration-dependent shell evolution, type-II shell evolution, in odd-$A$ nuclei is discussed for the first time. Our results will facilitate future studies of single-particle neutron states.

We report on the measurement of the beam asymmetry $\mathrm{\Sigma }$ for the reactions $\vec{\gamma }p\to p\eta$ and $\vec{\gamma }p\to p{\eta }^{\prime }$ from the GlueX experiment using an 8.2–8.8-GeV linearly polarized tagged photon beam incident on a liquid hydrogen target in Hall D at Jefferson Laboratory. These measurements are made as a function of momentum transfer $-t$ with significantly higher statistical precision than our earlier $\eta$ measurements and are the first measurements of ${\eta }^{\prime }$ in this energy range. We compare the results to theoretical predictions based on $t$-channel quasiparticle exchange. We also compare the ratio of ${\mathrm{\Sigma }}_{\eta }$ to ${\mathrm{\Sigma }}_{{\eta }^{\prime }}$ to these models as this ratio is predicted to be sensitive to the amount of $s\overline{s}$ exchange in the production. We find that photoproduction of both $\eta$ and ${\eta }^{\prime }$ is dominated by natural parity exchange with little dependence on $-t$.