We present fully local versions of the minimally nonlocal nucleon-nucleon potentials constructed in a previous paper [Piarulli et al., Phys. Rev. C 91, 024003 (2015)], and use them in hypersperical harmonics and quantum Monte Carlo calculations of ground and excited states of ${}^3\mathrm{H}$, ${}^3\mathrm{He}$, ${}^4\mathrm{He}$, ${}^6\mathrm{He}$, and ${}^6\mathrm{Li}$ nuclei. The long-range part of these local potentials includes one- and two-pion exchange contributions without and with $\mathrm{\Delta }$ isobars in the intermediate states up to order $Q^3$ ($Q$ denotes generically the low momentum scale) in the chiral expansion, while the short-range part consists of contact interactions up to order $Q^4$. The low-energy constants multiplying these contact interactions are fitted to the 2013 Granada database in two different ranges of laboratory energies, either 0–125 MeV or 0–200 MeV, and to the deuteron binding energy and $nn$ singlet scattering length. Fits to these data are performed for three models characterized by long- and short-range cutoffs, $R_{\mathrm{L}}$ and $R_{\mathrm{S}}$, respectively, ranging from $(R_{\mathrm{L}},R_{\mathrm{S}})=(1.2,0.8)$ fm down to $(0.8,0.6)$ fm. The long-range (short-range) cutoff regularizes the one- and two-pion exchange (contact) part of the potential.

The hyperfine spectra of ${}^{51,53-64}\mathrm{Mn}$ were measured in two experimental runs using collinear laser spectroscopy at ISOLDE, CERN. Laser spectroscopy was performed on the atomic $3d^{5}4s^2{}^{6}S_{5/2}\to 3d^{5}4s4p{}^{6}P_{3/2}$ and ionic $3d^{5}4s{}^5{S}_2\to 3d^{5}4p{}^5{P}_3$ transitions, yielding two sets of isotope shifts. The mass and field shift factors for both transitions have been calculated in the multiconfiguration Dirac-Fock framework and were combined with a King plot analysis in order to obtain a consistent set of mean-square charge radii which, together with earlier work on neutron-deficient Mn, allow the study of nuclear structure changes from $N=25$ across $N=28$ up to $N=39$. A clear development of deformation is observed towards $N=40$, confirming the conclusions of the nuclear moments studies. From a Monte Carlo shell-model study of the shape in the Mn isotopic chain, it is suggested that the observed development of deformation is not only due to an increase in static prolate deformation but also due to shape fluctuations and triaxiality. The changes in mean-square charge radii are well reproduced using the Duflo-Zuker formula except in the case of large deformation.

Within this work we present a consistent approach to quadrupole-octupole collective vibrations coupled with the rotational motion. A realistic collective Hamiltonian with variable mass-parameter tensor and potential obtained through the macroscopic-microscopic Strutinsky-like method with particle-number-projected BCS (Bardeen–Cooper–Schrieffer) approach in full vibrational and rotational, nine-dimensional collective space is diagonalized in the basis of projected harmonic oscillator eigensolutions. This orthogonal basis of zero-, one-, two-, and three-phonon oscillator-like functions in vibrational part, coupled with the corresponding Wigner function is, in addition, symmetrized with respect to the so-called symmetrization group, appropriate to the collective space of the model. In the present model it is $D_4$ group acting in the body-fixed frame. This symmetrization procedure is applied in order to provide the uniqueness of the Hamiltonian eigensolutions with respect to the laboratory coordinate system. The symmetrization is obtained using the projection onto the irreducible representation technique. The model generates the quadrupole ground-state spectrum as well as the lowest negative-parity spectrum in ${}^{156}\mathrm{Gd}$ nucleus. The interband and intraband $B\left(E1\right)$ and $B\left(E2\right)$ reduced transition probabilities are also calculated within those bands and compared with the recent experimental results for this nucleus. Such a collective approach is helpful in searching for the fingerprints of the possible high-rank symmetries (e.g., octahedral and tetrahedral) in nuclear collective bands.

To investigate the systematics of mixed-symmetry states in $N=52$ isotones, a relativistic Coulomb excitation experiment was performed during the PreSPEC campaign at the GSI Helmholtzzentrum für Schwerionenforschung to determine $E2$ transition strengths to $2^{+}$ states of the radioactive nucleus ${}^{88}\text{Kr}$. Absolute transition rates could be measured towards the first and third $2^{+}$ states. For the latter a mixed-symmetry character is suggested on the basis of the indication for a strong $M1$ transition to the fully symmetric $2_1{}^{+}$ state, extending the knowledge of the $N=52$ isotones below $Z=40$. A comparison with the proton-neutron interacting boson model and shell-model predictions is made and supports the assignment.

The distribution of single-particle strength in ${}^{67,69}\mathrm{Ni}$ was characterized with one-neutron knockout reactions from intermediate-energy ${}^{68,70}\mathrm{Ni}$ secondary beams, selectively populating neutron-hole configurations at $N=39$ and 41, respectively. The spectroscopic strengths deduced from the measured partial cross sections to the individual final states, as tagged by their $\gamma$-ray decays, are used to identify and quantify neutron configurations in the wave functions. While ${}^{69}\mathrm{Ni}$ compares well with shell-model predictions, the results for ${}^{67}\mathrm{Ni}$ challenge the validity of current effective shell-model Hamiltonians by revealing discrepancies that cannot be explained so far. These results suggest that our understanding of the low-lying states in the neutron-rich, semimagic Ni isotopes may be incomplete and requires further investigation on both the experimental and theoretical sides.

A self-consistent description for hot $\mathrm{\Lambda }$ hypernuclei in hypothetical big boxes is developed within the relativistic Thomas-Fermi approximation in order to investigate directly the liquid-gas phase coexistence in strangeness finite nuclear systems. We use the relativistic mean-field model for nuclear interactions. The temperature dependence of $\mathrm{\Lambda }$ hyperon density, $\mathrm{\Lambda }$ hyperon radius, excitation energies, specific heat, and the binding energies of $\mathrm{\Lambda }$ hypernuclei from ${}_{\mathrm{\Lambda }}{}^{16}\mathrm{O}$ to ${}_{\mathrm{\Lambda }}{}^{208}\mathrm{Pb}$ in phase transition region are calculated by using the subtraction procedure in order to separate the hypernucleus from the surrounding baryon gas. The $\mathrm{\Lambda }$ central density is very sensitive to the temperature. The radii of $\mathrm{\Lambda }$ hyperon at high temperature become very large. In the relativistic Thomas-Fermi approximation with the subtraction procedure, the properties of hypernuclei are independent of the size of the box in which the calculation is performed. The level density parameters of hypernuclei in the present work are confirmed to be almost constant at low temperature. It is also found that the single-$\mathrm{\Lambda }$ binding energies of $\mathrm{\Lambda }$ hypernuclei are largely reduced with increasing temperature.

The structure of neutron-rich ${}^{96,98}\mathrm{Sr}$ nuclei was investigated by low-energy safe Coulomb excitation of radioactive beams at the REX-ISOLDE facility, CERN, with the MINIBALL spectrometer. A rich set of transitional and diagonal $E2$ matrix elements, including those for non-yrast structures, has been extracted from the differential Coulomb-excitation cross sections. The results support the scenario of a shape transition at $N=60$, giving rise to the coexistence of a highly deformed prolate and a spherical configuration in ${}^{98}\mathrm{Sr}$, and are compared to predictions from several theoretical calculations. The experimental data suggest a significant contribution of the triaxal degree of freedom in the ground state of both isotopes. In addition, experimental information on low-lying states in ${}^{98}\mathrm{Rb}$ has been obtained.

Based on an extended multiphase transport model, which includes mean-field potentials in both the partonic and hadronic phases, uses the mix-event coalescence, and respects charge conservation during the hadronic evolution, we study the collision energy dependence of the elliptic flow splitting between particles and their antiparticles. This extended transport model reproduces reasonably well the experimental data at lower collision energies but only describes qualitatively the elliptic flow splitting at higher beam energies. The present study thus indicates the existence of other mechanisms for the elliptic flow splitting besides the mean-field potentials and the need of further improvements of the multiphase transport model.

Measurements of anisotropic flow Fourier coefficients ($v_n$) for inclusive charged particles and identified hadrons ${\pi }^{\pm }, K^{\pm }, p$, and $\overline{p}$ produced at midrapidity in $\mathrm{Cu}+\mathrm{Au}$ collisions at $\sqrt{s_{{}_{\mathit{NN}}}}=200$ GeV are presented. The data were collected in 2012 by the PHENIX experiment at the Relativistic Heavy-Ion Collider (RHIC). The particle azimuthal distributions with respect to different-order symmetry planes ${\mathrm{\Psi }}_n$, for $n=1$, 2, and 3 are studied as a function of transverse momentum $p_T$ over a broad range of collision centralities. Mass ordering, as expected from hydrodynamic flow, is observed for all three harmonics. The charged-particle results are compared with hydrodynamical and transport model calculations. We also compare these $\mathrm{Cu}+\mathrm{Au}$ results with those in $\mathrm{Cu}+\mathrm{Cu}$ and $\mathrm{Au}+\mathrm{Au}$ collisions at the same $\sqrt{s_{\mathit{NN}}}$ and find that the $v_2$ and $v_3$, as a function of transverse momentum, follow a common scaling with $1/\left({\varepsilon }_n{N}_{\mathrm{part}}^{1/3}\right)$.

The decay modes of recently synthesized superheavy nuclei are investigated by comparing the $\alpha$-decay half-lives with the spontaneous fission half-lives. $\alpha$-decay half-lives are calculated using the Coulomb and proximity potential model for deformed nuclei (CPPMDN). The agreement between theoretical and experimental $\alpha$ half-lives shows the predictability of the CPPMDN in the superheavy region. A modified formula is proposed for calculating the spontaneous fission half-lives including the shell correction. The agreement between theoretical predictions and experimental results of spontaneous fission half-lives is satisfactory for heavy and superheavy nuclei ranging from Th to Fl. A comparison between the spontaneous fission half-lives computed using eight different formalisms is performed for even-even superheavy nuclei in the range of $108\le Z\le 120$. Even though all these models can reproduce the experimental spontaneous fission half-lives, model-to-model variations in predicting the fission half-lives in superheavy region is evident from the study.

The interaction between nuclei in the inner crust of neutron stars consists of two contributions: the so-called “direct” interaction and an “induced” one due to density changes in the neutron fluid. For large nuclear separations $r$ the contributions from nuclear forces to each of these terms are shown to be nonzero. In the static limit they are equal in magnitude but have opposite signs and they cancel exactly. We analyze earlier results on effective interactions in light of this finding. We consider the properties of long-wavelength collective modes and, in particular, calculate the degree of mixing between the lattice phonons and the phonons in the neutron superfluid. Using microscopic theory, we calculate the net non-Coulombic contribution to the nucleus-nucleus interaction and show that, for large $r$, the leading term is due to exchange of two phonons and varies as $1/r^7$; it is an analog of the Casimir-Polder interaction between neutral atoms.

Shear viscosity $\eta$ is calculated for the nuclear matter described as a system of interacting nucleons with the van der Waals (VDW) equation of state. The Boltzmann-Vlasov kinetic equation is solved in terms of the plane waves of the collective overdamped motion. In the frequent-collision regime, the shear viscosity depends on the particle-number density $n$ through the mean-field parameter $a$, which describes attractive forces in the VDW equation. In the temperature region $T=15–40$ MeV, a ratio of the shear viscosity to the entropy density $s$ is smaller than 1 at the nucleon number density $n=(0.5–1.5)n_0^{}$, where $n_0^{}=0.16{\mathrm{fm}}^{-3}$ is the particle density of equilibrium nuclear matter at zero temperature. A minimum of the $\eta /s$ ratio takes place somewhere in a vicinity of the critical point of the VDW system. Large values of $\eta /s\gg 1$ are, however, found in both the low-density, $n\ll n_0^{}$, and high-density, $n>2n_0^{}$, regions. This makes the ideal hydrodynamic approach inapplicable for these densities.

Some time ago we derived from the QCD Lagrangian an equation of state (EOS) for cold quark matter which can be considered an improved version of the MIT bag model EOS. Compared to the latter, our equation of state reaches higher values of the pressure at comparable baryon densities. This feature is due to perturbative corrections and also to nonperturbative effects. Later we applied this EOS to the study of compact stars, discussing the absolute stability of quark matter and computing the mass-radius relation for self-bound (strange) stars. We found maximum masses of the sequences with more than two solar masses, in agreement with recent experimental observations. In the present work we include the magnetic field in the equation of state and study how it changes the stability conditions and the mass-radius curves.

$\gamma$-ray and fast-timing spectroscopy were used to study levels in ${}^{30}\mathrm{Al}$ populated following the ${\beta }^{-}$ decay of ${}^{30}\mathrm{Mg}$. Five new transitions and three new levels were located in ${}^{30}\mathrm{Al}$. A search was made to identify the third $1^{+}$ state expected at an excitation energy of $\sim 2.5$ MeV. Two new levels were found, at 3163.9 and 3362.5 keV, that are firm candidates for this state. Using the advanced time-delayed (ATD) $\beta \gamma \gamma$(t) method we have measured the lifetime of the 243.8-keV state to be $T_{1/2}=15\left(4\right)\mathrm{ps}$, which implies that the 243.8-keV transition is mainly of $M1$ character. Its fast $B(M1;2^{+}\to 3^{+})$ value of 0.10(3) W.u. is in very good agreement with the USD shell-model prediction of 0.090 W.u. The 1801.5-keV level is the only level observed in this study that could be a candidate for the second excited $2^{+}$ state.

We study the convergence properties of nuclear binding energies and two-neutron separation energies obtained with self-consistent mean-field calculations based on the Hartree-Fock-Bogolyubov (HFB) method with Gogny-type effective interactions. Owing to lack of convergence in a truncated working basis, we employ and benchmark one of the recently proposed infrared energy correction techniques to extrapolate our results to the limit of an infinite model space. We also discuss its applicability to global calculations of nuclear masses.

We investigate effects of neutron-proton ($np$) pairing correlations on the Gamow-Teller (GT) transition of ${}^{24,26}\mathrm{Mg}$ by explicitly taking into account deformation effects. Our calculation is performed by a deformed quasiparticle random phase approximation (DQRPA) which includes the deformation at the Bardeen-Cooper-Schrieffer and RPA stage. In this paper, we include the $np$ pairing as well as neutron-neutron ($nn$) and proton-proton ($pp$) paring correlations to the DQRPA. Our new formalism is applied to the GT transition of well-known deformed Mg isotopes. The $np$ pairing effect is found to affect more or less the GT distribution of ${}^{24}\mathrm{Mg}$ and ${}^{26}\mathrm{Mg}$. But the deformation effect turns out to be much larger than the $np$ paring effect because the Fermi surfaces smear more widely by the deformation rather than the $np$ pairing correlations. Correlations between the deformation and the $np$ pairing effects and their ambiguities are also discussed with the comparison to experimental GT strength data by triton and ${}^3\mathrm{He}$ beams.