We analyze the stellar properties of the relativistic mean-field (RMF) parametrizations shown to be consistent with the recently studied constraints related to nuclear matter, pure neutron matter, symmetry energy, and its derivatives [Phys. Rev. C 90, 055203 (2014)]. Our results show that only two RMF parametrizations do not allow the emergence of the direct Urca process, important aspect regarding the evolution of a neutron star. Moreover, among all approved RMF models, fourteen of them produce neutron stars with maximum masses inside the range $1.93\le M/M_{\odot }\le 2.05$, with $M_{\odot }$ being the solar mass. Only three models yield maximum masses above this range and a discussion on the inclusion of hyperons is presented. Finally, we verified that the models satisfying the neutron star maximum mass constraint do not observe the squared sound velocity bound; namely, $v_s^2<1/3$, corroborating recent findings. However, the recently proposed $\sigma$-cut scheme can make the RMF models consistent with both constraints, depending on the isoscalar-vector interaction of each parametrization.

We describe electromagnetic and favored $\alpha$ transitions to rotational bands in odd-mass nuclei built upon a single particle state with angular momentum projection $\mathrm{\Omega }\ne \frac{1}{2}$ in the region $88\le Z\le 98$. We use the particle coupled to an even-even core approach described by the coherent state model and the coupled channels method to estimate partial $\alpha$-decay widths. We reproduce the energy levels of the rotational band where favored $\alpha$ transitions occur for 26 nuclei and predict $B\left(E2\right)$ values for electromagnetic transitions to the band head using a deformation parameter and a Hamiltonian strength parameter for each nucleus, together with an effective collective charge depending linearly on the deformation parameter. Where experimental data are available, the contribution of the single particle effective charge to the total $B\left(E2\right)$ value is calculated. The Hamiltonian describing the $\alpha$-nucleus interaction contains two terms, a spherically symmetric potential given by the double-folding of the M3Y nucleon-nucleon interaction plus a repulsive core simulating the Pauli principle and a quadrupole-quadrupole (QQ) interaction. The $\alpha$-decaying state is identified as a narrow outgoing resonance in this potential. The intensity of the transition to the first excited state is reproduced by the QQ coupling strength. It depends linearly both on the nuclear deformation and the square of the reduced width for the decay to the band head, respectively. Predicted intensities for transitions to higher excited states are in a reasonable agreement with experimental data. This formalism offers a unified description of energy levels, electromagnetic and favored $\alpha$ transitions for known heavy odd-mass $\alpha$ emitters.

Background: Fission fragments from heavy ion collisions with actinide nuclei show mass-asymmetric and mass-symmetric components. The relative probabilities of these two components vary rapidly with beam energy with respect to the capture barrier, indicating a strong dependence on the alignment of the deformed nucleus with the partner in the collisions.

Purpose: To study the characteristics of the mass-asymmetric quasifission component by reproducing the experimental mass-angle distributions to investigate mass evolution and sticking times.

Methods: Fission fragment mass-angle distributions were measured for the ${}^{34}\text{S}+{}^{232}\text{Th}$ reaction. Simulations to match the measurements were made by using a classical phenomenological approach. Mass ratio distributions and angular distributions of the mass-asymmetric quasifission component were simultaneously fit to constrain the free parameters used in the simulation.

Results: The mass-asymmetric quasifission component—predominantly originating from tip (axial) collisions with the prolate deformed ${}^{232}\text{Th}$—is found to be peaked near $A=200$ at all energies and center-of-mass angles. A Monte Carlo model using the standard mass equilibration time constant of $5.2\times {10}^{-21}$ s predicts more symmetric mass splits. Three different hypotheses assuming (i) a mass halt at $A=200$, (ii) a slower mass equilibration time, or (iii) a Fermi-type mass drift function reproduced the main experimental features.

Conclusions: In tip collisions for the ${}^{34}\text{S}+{}^{232}\text{Th}$ reaction, mass-asymmetric fission with $A\sim 200$ is the dominant outcome. The average sticking time is found to be $\sim 7\times {10}^{-21}$ s, independent of the scenario used for mass evolution.

The excitation functions of heavy residues, produced in the interaction of ${}^{14}\mathrm{N}$ with ${}^{103}\mathrm{Rh}$, have been measured over the projectile energy region from a threshold up to 400 MeV by means of the activation method in conjunction with γ-ray spectroscopy. Cross sections for 15 reaction residues are presented, namely, ${}^{104}\mathrm{Cd}, {}^{103-105}\mathrm{Ag}, {}^{99-101}\mathrm{Pd}, {}^{97,99,101}\mathrm{Rh}, {}^{95,97}\mathrm{Ru}$, and ${}^{94-96}\mathrm{Tc}$. The experimental data are compared with theoretical model predictions using the hybrid Monte Carlo simulation model as implemented in the recently released alice2014 code. The theory assumes that the dominant pre-equilibrium mechanism includes multinucleon and cluster emissions in the initial stages of the interaction between the projectile and the target nucleus. Overall, the theoretical predictions provide a satisfactory agreement with the trend of the present experimental results for most of the observed reaction residues. This provides strong evidence that the underlying reaction mechanisms in the code are appropriately described. Overall, the Obninsk level densities give the best results in the present study.

Background: $r$-process nucleosynthesis models rely, by necessity, on nuclear structure models for input. Particularly important are $\beta$-decay half-lives of neutron-rich nuclei. At present only a single systematic calculation exists that provides values for all relevant nuclei making it difficult to test the sensitivity of nucleosynthesis models to this input. Additionally, even though there are indications that their contribution may be significant, the impact of first-forbidden transitions on decay rates has not been systematically studied within a consistent model.

Purpose: Our goal is to provide a table of $\beta$-decay half-lives and $\beta$-delayed neutron emission probabilities, including first-forbidden transitions, calculated within a fully self-consistent microscopic theoretical framework. The results are used in an $r$-process nucleosynthesis calculation to asses the sensitivity of heavy element nucleosynthesis to weak interaction reaction rates.

Method: We use a fully self-consistent covariant density functional theory (CDFT) framework. The ground state of all nuclei is calculated with the relativistic Hartree-Bogoliubov (RHB) model, and excited states are obtained within the proton-neutron relativistic quasiparticle random phase approximation ($pn$-RQRPA).

Results: The $\beta$-decay half-lives, $\beta$-delayed neutron emission probabilities, and the average number of emitted neutrons have been calculated for 5409 nuclei in the neutron-rich region of the nuclear chart. We observe a significant contribution of the first-forbidden transitions to the total decay rate in nuclei far from the valley of stability. The experimental half-lives are in general well reproduced for even-even, odd-$A$, and odd-odd nuclei, in particular for short-lived nuclei. The resulting data table is included with the article as Supplemental Material.

Conclusions: In certain regions of the nuclear chart, first-forbidden transitions constitute a large fraction of the total decay rate and must be taken into account consistently in modern evaluations of half-lives. Both the $\beta$-decay half-lives and $\beta$-delayed neutron emission probabilities have a noticeable impact on the results of heavy element nucleosynthesis models.

We suggest a new mechanism for the energy loss of fast heavy quarks in quark-gluon plasma. This mechanism is based on pion production caused by the anomalous chromomagnetic quark-gluon-pion interaction induced by strong topological fluctuations of the gluon fields represented by instantons. We found that this mechanism makes a considerable contribution to the collisional energy loss of a heavy quark in quark-gluon plasma, which shows a nontrivial role of nonperturbative phenomena in strongly interacting quark-gluon plasma.

Nucleon-nucleon $\left(\mathit{NN}\right)$ scattering is studied by applying an approach based on the $\mathit{N}/\mathit{D}$ method and chiral perturbation theory (ChPT), whose dynamical input per partial wave consists of the imaginary part of the $\mathit{NN}$ partial-wave amplitude along the left-hand cut. The latter is calculated in one-loop ChPT up to and including next-to-next-to-leading order (NNLO). A power counting for the subtraction constants is established, which is appropriate for those subtractions attached to both the left- and the right-hand cuts. A quite good reproduction of the Nijmegen partial-wave analysis phase shifts and mixing angles results, which implies a steady improvement in the accurateness achieved by increasing the chiral order in the calculation of the dynamical input. I discuss that it is not necessary to fine tune the chiral counterterms $c_i$ determined from pion-nucleon scattering to agree with $\mathit{NN}$ data, but instead one should perform the iteration of two-nucleon intermediate states in a well-defined way so as to keep proper unitarity and analyticity. It is also confirmed at NNLO the long-range correlations between the $\mathit{NN} S$-wave effective ranges and scattering lengths, when employing only once-subtracted dispersion relations, that hold up to around 10% when compared with experimental values.

Prompt $\gamma$ rays of isotopically identified neutron-rich isotopes of Cd, produced in transfer- and fusion-fission induced by the ${}^{238}\mathrm{U}$ beam at 6.2 MeV/u on a ${}^9\mathrm{Be}$ target, were measured using the EXOGAM $\gamma$-ray detector array and the magnetic spectrometer VAMOS++. New results for the level scheme of ${}^{121,123}\mathrm{Cd}$, extending to relatively large angular momentum are reported. The energy levels above 2-MeV excitation energy, are found to differ from those observed in lighter isotopes of Cd indicating a change in structure in these more neutron-rich nuclei. These states are not explained by large-scale shell model calculations, that explain well the structure of the underlying Sn isotopes and the neighboring even-A Cd isotopes. The present data, especially for the odd-A nuclei, point to a deficiency in the matrix elements related to the p-n residual interaction and provide a new domain for testing widely used shell model interactions employed for understanding the evolution of structure in neutron-rich nuclei.

The three-body force is indispensable in nuclear energy density functionals, which leads to a density-dependent two-body term in the Hartree–Fock approach. Usually, a single fractional power of density dependency is adopted. We consider the possibility of an additional higher-order density dependence in extended Skyrme forces. As a result, new extended Skyrme parametrizations based on the SLy4 force have been obtained and the improvements in descriptions of global nuclei have been demonstrated. The higher-order term can also substantially affect nuclear properties in the high-density region in general ways.

In this paper a new procedure to smooth out the initial energy densities of hydrodynamics is employed to show that the initial spatial eccentricities ${\varepsilon }_{m,n}$, which drive the final state flow harmonics $v_n$, are remarkably robust with respect to variations of the underlying scale of initial energy density spatial gradients, $\lambda$, in nucleus-nucleus collisions. For $\sqrt{s}=2.76$ TeV Pb+Pb collisions, the ${\varepsilon }_{m,n}$'s (across centrality classes) change by less than 10% if the scale of fluctuations is varied from 0.1 to 1 fm. We show, using the 2+1 Lagrangian hydrodynamic code v-USPhydro, that this robustness is transferred to the final $v_n$'s computed within event-by-event viscous hydrodynamics. This indicates that the flow harmonics in nucleus-nucleus collisions are not particularly sensitive to the underlying microscopic subnucleon physics below the confinement scale. On the other hand, the eccentricities of top 1% high multiplicity $\sqrt{s}=5.02$ TeV $p+\mathrm{Pb}$ collisions are found to be very sensitive to subnucleonic scale fluctuations, which should be contrasted with the robustness found in peripheral Pb+Pb collisions with the same multiplicity.

The cross sections of the ${}^{103}\mathrm{Rh}(p,\gamma ){}^{104}\mathrm{Pd}$ and the ${}^{113,115}\mathrm{In}(p,\gamma ){}^{114,116}\mathrm{Sn}$ reactions have been determined from $\gamma$ angular distribution measurements carried out at beam energies from 2 to 3.5 MeV. An array of four highly efficient HPGe detectors all shielded with BGO crystals for Compton background suppression was used. Astrophysical $S$ factors and reaction rates were deduced from the measured cross sections. Statistical model calculations were performed using the Hauser-Feshbach (HF) code TALYS and were compared with the new data. A good agreement between theory and experiment was found. In addition, the effect of different combinations of the nuclear input parameters entering the HF calculations on the ground-state reaction rates was investigated. It was found that these rates differ by a factor 3 at the most, being thus within the average discrepancies observed between calculated $p$-nuclei abundances and observations, if certain combinations of optical model potentials, nuclear level densities, and $\gamma$-ray strength functions are used.

We present an extension of the random-phase approximation (RPA) where the RPA phonons are used as building blocks to construct the excited states. In our model, that we call double RPA (DRPA), we include up to two RPA phonons. This is an approximate and simplified way, with respect to the full second random-phase approximation (SRPA), to extend the RPA by including two-particle–two-hole configurations. Some limitations of the standard SRPA model, related to the violation of the stability condition, are not encountered in the DRPA. We also verify in this work that the energy-weighted sum rules are satisfied. The DRPA is applied to low-energy modes and giant resonances in the nucleus ${}^{16}\mathrm{O}$. We show that the model (i) produces a global downwards shift of the energies with respect to the RPA spectra and (ii) provides a shift that is, however, strongly reduced compared to that generated by the standard SRPA. This model represents an alternative way of correcting for the SRPA anomalous energy shift, compared to a recently developed extension of the SRPA, where a subtraction procedure is applied. The DRPA provides results in good agreement with the experimental energies, with the exception of those low-lying states that have a dominant two-particle–two-hole nature. For describing such states, higher-order calculations are needed.

We extend the method of antisymmetrized molecular dynamics (AMD) to investigate dineutron correlation. We regard the total system as the core plus two valence neutrons in the AMD framework and treat the valence neutron wave functions by multirange Gaussians with the $d$-constraint method, in which the distance between the core and the center of mass of the two neutrons is constrained, to describe the size changing effect and the motion of two neutrons. We apply this method to the ground state of ${}^{10}\mathrm{Be}$ as an example and investigate the motion of two neutrons around a largely deformed ${}^8\mathrm{Be}$ core by analyzing the two-neutron overlap function around the core. Comparing the results including the different ${}^8\mathrm{Be}$ core structures, we show that the core structure plays an important role in dineutron formation and expansion from the core. The radial fluctuation in the core leads to the expansion of the core potential to the farther region and, as a result, two valence neutrons can be expanded far from the core to form a dineutron. Differently, when the core is less deformed, the dineutron is dissociated by the spin-orbit potential at the surface of the core. We can investigate the dineutron correlation clearly by using the present framework and conclude that the framework is effective for the studies of dineutron correlation.

The importance of microphysical inputs from laboratory nuclear experiments and theoretical nuclear structure calculations in the understanding of core-collapse dynamics and the subsequent supernova explosion is largely recognized in the recent literature. In this work, we analyze the impact of the masses of very neutron-rich nuclei on the matter composition during collapse and the corresponding electron-capture rate. To this end, we introduce an empirical modification of the popular Duflo-Zuker mass model to account for possible shell quenching far from stability. We study the effect of this quenching on the average electron-capture rate. We show that the pre-eminence of the closed shells with $N=50$ and $N=82$ in the collapse dynamics is considerably decreased if the shell gaps are reduced in the region of ${}^{78}\mathrm{Ni}$ and beyond. As a consequence, local modifications of the overall electron-capture rate of up to 30% can be expected, depending on the strength of magicity quenching. This finding has potentially important consequences on the entropy generation, the neutrino emissivity, and the mass of the core at bounce. Our work underlines the importance of new experimental measurements in this region of the nuclear chart, the most crucial information being the nuclear mass and the Gamow-Teller strength. Reliable microscopic calculations of the associated elementary rate, in a wide range of temperatures and electron densities, optimized on these new empirical information, will be additionally needed to get quantitative predictions of the collapse dynamics.

I have used the low-energy data of the new Nijmegen ESC08 baryon-baryon interactions for the systems with strangeness 0, $-1$, and $-2$ to construct a separable potential model of the $\mathrm{\Lambda }\mathrm{\Lambda }N-\mathrm{\Xi }NN$ system to study the position and width of the three-body $\left(I,J^P\right)=\left(\frac{1}{2},{\frac{1}{2}}^{+}\right)$ resonance. I found that the $\left(\frac{1}{2},{\frac{1}{2}}^{+}\right)$ tribaryon has a mass of 3194 MeV, just below the $\mathrm{\Xi }d$ threshold, and a width of only 0.09 MeV.

Neutrinoless double-$\beta$ ($0\nu \beta \beta$) decay is a promising beyond standard model process. Two-neutrino double-$\beta$ ($2\nu \beta \beta$) decay is an associated process that is allowed by the standard model, and it was observed in about 10 isotopes, including decays to the excited states of the daughter. ${}^{124}\mathrm{Sn}$ was the first isotope whose double-$\beta$ decay modes were investigated experimentally, and despite few other recent efforts, no signal has been seen so far. Shell model calculations were able to make reliable predictions for $2\nu \beta \beta$ decay half-lives. Here we use shell model calculations to predict the $2\nu \beta \beta$ decay half-life of ${}^{124}\mathrm{Sn}$. Our results are quite different from the existing quasiparticle random-phase approximation results, and we envision that they will be useful for guiding future experiments. We also present shell model nuclear matrix elements for two potentially competing mechanisms to the $0\nu \beta \beta$ decay of ${}^{124}\mathrm{Sn}$.

The modified number of constituent quark (NCQ) scaling $v_n/n_q^{n/2}\sim K{E}_T/n_q$ for mesons and baryons and the scaling relation $v_n\sim v_2^{n/2}$ for higher-order anisotropic flows, which were observed experimentally, have been investigated at the top energy of Relativistic Heavy-Ion Collider. It has been found that the modified NCQ scaling cannot be obtained from the naive coalescence even by taking into account event-by-event fluctuations but may be due to hadronic afterburner or thermal freeze-out. In addition, we observed that the behavior of the $v_n/v_2^{n/2}$ ratio is sensitive to the partonic interaction. Further insights about the relation between the two scalings are discussed.