Heavy flavor probes are sensitive to the properties of the quark gluon plasma (QGP) produced in relativistic heavy-ion collisions. A huge amount of effort has been devoted to studying different aspects of the heavy-ion collisions using heavy flavor particles. In this work, we study the dynamics of heavy quark transport in the QGP medium using the rapidity dependence of heavy flavor observables. We calculate the nuclear modification of $B$- and $D$-meson spectra as well as spectra of leptons from heavy flavor decays in the rapidity range $[-4.0,4.0]$. We use an implementation of the improved Langevin equation with gluon radiation on top of a ($3+1$)-dimensional relativistic viscous hydrodynamical background for several collision setups. We find that the rapidity dependence of the heavy quark modification is determined by the interplay between the smaller size of the medium, which affects the path length of the heavy quarks, and the softer heavy quark initial production spectrum. We compare our results with available experimental data and present predictions for open heavy flavor meson $R_{AA}$ at finite rapidity.

Coherent photoproduction of ${\pi }^0{\pi }^0$ and ${\pi }^0\eta$ on nuclei with $A\le 7$ is systematically studied in the energy region from the threshold to the laboratory photon energy $E_{\gamma }=2$ GeV. The amplitude of photoproduction on nuclei is derived in the impulse approximation taking account of certain processes responsible for the meson-nucleus final-state interaction. For the first time, the unified microscopic approach is used to calculate effects such as rescattering of the $\pi N\to \pi N$ and $\pi N\to \eta N$ pions from spectator nucleons, photoproduction of ${\pi }^{+/-}{\pi }^0{\pi }^0$ and ${\pi }^{+/-}{\pi }^0\eta$, and the follow-on absorption of ${\pi }^{+/-}$ by spectator nucleons, as well as three-body $\pi \text{−}NN$ and $\eta \text{−}NN$ interaction among effects being responsible for the meson-nucleus final-state interaction. Direct calculation shows total cross sections of ${\pi }^0{\pi }^0$ and ${\pi }^0\eta$ photoproduction to be strongly dependent both on the target nucleus isospin, and the target nucleus model.

Neutral-current neutrino scattering from the deuteron leading to proton-neutron final states is considered using an approach that incorporates relativistic dynamics and consequently provides robust modeling at relatively high energies and momenta. In this work the focus is placed on the fully exclusive reaction where both the proton and neutron in the final state are assumed to be detected. Accordingly, the incident neutrino energy, the neutrino scattering angle, and the scattered neutrino's energy can all be reconstructed. It is shown that for specific choices of kinematics the reaction proceeds mainly via scattering from the proton, while for other choices of kinematics it proceeds mainly from the neutron. Specific asymmetries are introduced to focus on these attributes. Measurements in both regions have the potential to yield valuable information on the nucleon's electroweak form factors at momentum transfers up to a (GeV/${c)}^2$. In particular, the cross sections are shown to be very sensitive to the isoscalar axial-vector form factor, and sensitive but less so to the magnetic strangeness form factor. Comparisons with other reactions, specifically charge-changing neutrino reactions and both parity-conserving and -violating electron scattering, have the potential to provide new ways to test the standard model.

An experimental study on the fusion dynamics of the ${}^7\mathrm{Li}+{}^{\text{nat}}\mathrm{Zr}$ reaction has been carried out within the 4.0 to 6.3 MeV/nucleon energy range by measuring cross sections of the populated residues with the help of $\gamma$-ray spectrometry. The equilibrium and pre-equilibrium reaction models have been used in the framework of empire3.2.2 to analyze the measured residual cross sections to shed light on the reaction mechanism involved in it. It indicates that the complete and incomplete fusion of ${}^7\mathrm{Li}$ contribute to the residual cross sections. Thus, the strength of incomplete fusion has been derived and is compared with other ${}^7\mathrm{Li}$-induced reactions in the similar mass range. Further, coupled channel (CC) calculations have been carried out to understand the effect of couplings in the fusion process. It has been observed that the fusion cross section is suppressed in ${}^7\mathrm{Li}+{}^{\text{nat}}\mathrm{Zr}$ reaction as compared to CC calculations far above the Coulomb barrier. The isomeric cross-section ratio has also been obtained from the measured cross sections of the isomeric pairs of ${}^{93,95}\mathrm{Tc}$ that describes the role of angular momentum and relative spins of the ground and isomeric states with the variation of bombarding energy.

The transverse momentum $\left(p_{\mathrm{T}}\right)$ distributions of $\mathrm{\Lambda }$, ${\mathrm{\Xi }}^{-}$, and ${\mathrm{\Omega }}^{-}$ baryons, their antiparticles, and $K_S^0$ mesons are measured in proton-proton $\left(pp\right)$ and proton-lead $\left(p\mathrm{Pb}\right)$ collisions at a nucleon-nucleon center-of-mass energy of 5.02 TeV over a broad rapidity range. The data, corresponding to integrated luminosities of 40.2 ${\mathrm{nb}}^{-1}$ and 15.6 ${\mu \mathrm{b}}^{-1}$ for $pp$ and $p\mathrm{Pb}$ collisions, respectively, were collected by the CMS experiment. The nuclear modification factor $R_{p\text{Pb}}$, which is defined as the ratio of the particle yield in $p\mathrm{Pb}$ collisions and a scaled $pp$ reference, is measured for each particle. A strong dependence on particle species is observed in the $p_{\mathrm{T}}$ range from 2 to 7 GeV, where $R_{p\text{Pb}}$ for $K_S^0$ is consistent with unity, while an enhancement ordered by strangeness content and/or particle mass is observed for the three baryons. In $p\mathrm{Pb}$ collisions, the strange hadron production is asymmetric about the nucleon-nucleon center-of-mass rapidity. Enhancements, which depend on the particle type, are observed in the direction of the Pb beam. The results are compared with predictions from epos lhc, which includes parametrized radial flow. The model is in qualitative agreement with the $R_{p\text{Pb}}$ data, but fails to describe the dependence on particle species in the yield asymmetries measured away from midrapidity in $p\mathrm{Pb}$ collisions.

We extend the SU(3) (Polyakov)–Nambu–Jona-Lasinio in two ways: We introduce the next-to-leading-order contribution (in $N_c$) in the partition function. This contribution contains explicit mesonic terms. We introduce a coupling between the gluon field and the quark degrees of freedom, which goes beyond a simple rescaling of the critical temperature. With both these improvements, we can reproduce, for vanishing chemical potentials, the lattice results for the thermal properties of a strongly interacting system like pressure, energy density, entropy density, interaction measure, and the speed of sound. Also, the expansion parameter toward small but finite chemical potentials agrees with the lattice results. Extending the calculations to finite chemical potentials (which does not require any new parameter), we find a first-order phase transition up to a critical end point of $T_{\mathrm{CEP}}=110\text{MeV}$ and ${\mu }_q=320\text{MeV}$. We calculate the mass of mesons and baryons as a function of temperature and chemical potential and the transition between the hadronic and the chirally restored phase. These calculations provide an equation of state in the whole $T,\mu$ plane an essential ingredient for dynamical calculations of ultrarelativistic heavy-ion collisions but also for the physics of neutron stars and neutron star collisions.

We discuss the prospects of using jets as precision probes in electron-nucleus collisions at the future Electron-Ion Collider (EIC). Jets produced in deep-inelastic scattering can be calibrated by a measurement of the scattered electron. Such electron-jet “tag and probe” measurements call for an approach that is orthogonal to most jet measurements at the Hadron-Electron Ring Accelerator (HERA) at DESY, as well as previous studies of jets at the future EIC. We present observables such as the electron-jet momentum balance, azimuthal correlations, and jet substructure, which can provide constraints on the parton transport coefficient in nuclei. We compare simulations and analytical calculations and provide estimates of the expected medium effects. Implications for detector design at the future EIC are discussed.

The iterative method recently proposed for determining the internal constitution of the outer crust of a nonaccreted neutron star is extended to magnetars by taking into account the Landau-Rabi quantization of electron motion induced by the presence of a very high magnetic field. It is shown that in the strongly quantizing regime, the method can be efficiently implemented using new analytical solutions for the transitions between adjacent crustal layers. Detailed numerical computations are performed to assess the performance and precision of the method.

Background: More than half of all the elements heavier than iron are made by the rapid neutron capture process (or $r$ process). For very-neutron-rich astrophysical conditions, such at those found in the tidal ejecta of neutron stars, nuclear fission determines the $r$-process endpoint, and the fission-fragment yields shape the final abundances of $110\le A\le 170$ nuclei. The knowledge of fission-fragment yields of hundreds of nuclei inhabiting very-neutron-rich regions of the nuclear landscape is thus crucial for the modeling of heavy-element nucleosynthesis.

Purpose: In this study, we propose a model for the fast calculation of fission-fragment yields based on the concept of shell-stabilized prefragments defined with help of the nucleonic localization functions.

Methods: To generate realistic potential-energy surfaces and nucleonic localizations, we apply Skyrme density-functional theory. The distribution of the neck nucleons among the two prefragments is obtained by means of a statistical model.

Results: We benchmark the method by studying the fission yields of ${}^{178}\mathrm{Pt},{}^{240}\mathrm{Pu},{}^{254}\mathrm{Cf}$, and ${}^{254,256,258}\mathrm{Fm}$ and show that it satisfactorily explains the experimental data. We then make predictions for ${}^{254}\mathrm{Pu}$ and ${}^{290}\mathrm{Fm}$ as two representative cases of fissioning nuclei that are expected to significantly contribute during the $r$-process nucleosynthesis occurring in neutron-star mergers.

Conclusions: The proposed framework provides an efficient alternative to microscopic approaches based on the evolution of the system in a space of collective coordinates all the way to scission. It can be used to carry out global calculations of fission-fragment distributions across the $r$-process region.

We have deduced the emission probability of the 447-keV $\gamma$ ray from the $\varepsilon +{\beta }^{+}$ decay of ${}^{137}\mathrm{Ce}^g$ (9.0 h) relative to that of the 254-keV $\gamma$ ray from the ${}^{137}\mathrm{Ce}^m$ (34.4 h) decay in transient equilibrium. The time-dependent factor in transient equilibrium was applied following the Bateman equation for a radioactive decay chain. The isotope was produced via the ${}^{139}\mathrm{La}\left(p,3n\right){}^{137}\mathrm{Ce}^{m,g}$ reaction by bombarding ${}^{\mathrm{nat}}\mathrm{La}$ with a proton beam from the 88-in. cyclotron at Lawrence Berkeley National Laboratory. $\gamma$-ray intensities were measured using an HPGe detector. The emission probability for the 447-keV $\gamma$ ray deduced in this work is 1.21(3) (that is 1.21 ± 0.03) per hundred parent decays, which differs significantly from an earlier published value of 2.24(10). We identify the source of this discrepancy to be an incorrect use of the time-dependent factor. Additionally, we have deduced the emission probability of the 504-keV $\gamma$ ray from the decay of ${}^{85}\mathrm{Y}^g$ (2.68 h) relative to that of the 232-keV $\gamma$ ray from the ${}^{85}\mathrm{Sr}^m$ (1.127 h) decay in transient equilibrium. The isotope was produced via the ${}^{86}\mathrm{Sr}(p,2n){}^{85}\mathrm{Y}^g$ reaction by bombarding ${}^{86}\mathrm{SrCO}_3$ with a proton beam at the same facility. The study confirms the assumption of the time-dependent correction for recommending the emission probability of the 504-keV $\gamma$ ray in the literature. Our work highlights the importance of explicit description by authors of any time-dependent correction they have made when reporting $\gamma$-ray intensities for nuclides in transient equilibrium. The need and significance of accurate and precise decay data of ${}^{137}\mathrm{Ce}^g$ and ${}^{85}\mathrm{Y}^g$ in basic science and medicine is briefly outlined.

We investigate microscopically the tunneling dynamics in spontaneous fission of atomic nuclei. To this end, we employ a schematic solvable model with a pairing-plus-quadrupole interaction. The spontaneous decay of a system is simulated by introducing a small imaginary part to the energy of a fission doorway state. We show that the many-body Hamiltonian can be reduced to an effective $2\times 2$ Hamiltonian, from which one can derive a simple approximate formula for the decay width. We particularly investigate the applicability of the adiabatic approximation, which has often been used in the literature. With typical value of the parameters, we find that the adiabatic approximation may underestimate the decay width by orders of magnitude, depending on the number of orbital transitions.

The low-lying collective spectra for an extended set of Xe nuclei are described within a phenomenological Bohr model with an exactly separable collective potential. The dependence of the collective potential on the $\gamma$ shape variable is chosen to allow the description of a phase transition between axial and triaxial shapes, while the $\beta$ excitations are described within the formalism of energy-dependent potentials in order to accommodate the different structure of the excited states. The combined contribution of these effects leads to a high fidelity description of the experimental spectra for ${}^{118–128}\mathrm{Xe}$ isotopes, especially in the excited rotational bands, which revealed a rapid onset of stable triaxial deformation in the ${}^{120}\mathrm{Xe}$ nucleus persisting also in the heavier isotopes. The critical nature of ${}^{120}\mathrm{Xe}$ is also reflected in its very strong state-dependence of the deformation properties.

The ELYO (extended Lee-Yang-Orsay) functional proposed in M. Grasso, D. Lacroix, and C. J. Yang [Phys. Rev. C 95, 054327 (2017)] belongs to the family of energy-density functionals (EDFs) inspired by effective-field theories and constrained by ab initio pseudodata. We present here an extension of this EDF which also accounts for the first $p$-wave term appearing in the low-density expansion from which it derives. It is shown that this enrichment of the ansatz on which the functional is based leads to a significant improvement of the description of neutronic systems, especially in regimes besides the pseudodata set employed to adjust the parameters. As an illustrative application, the mass-radius relation of neutron stars is considered. In contrast to its initial version, the new functional predicts values which are qualitatively consistent with recent observations.

Analysis of the differential cross sections for ${}^6\mathrm{Li}$ elastic scattering from ${}^{24}\mathrm{Mg}$, ${}^{28}\mathrm{Si}$, ${}^{40}\mathrm{Ca}$, ${}^{48}\mathrm{Ca}$, ${}^{58}\mathrm{Ni}$, ${}^{90}\mathrm{Zr}$, and ${}^{116}\mathrm{Sn}$ at 40 MeV/nucleon is performed within the framework of the optical double folding model. Simple phenomenological effective nucleon-nucleon interaction represented by a density-independent single Yukawa term is utilized to generate the real optical potential part. The derived potentials in conjunction with imaginary parts expressed in phenomenological volume Woods-Saxon forms have been successfully used to reproduce the seven sets of data. For the sake of comparison, the same measurements are reanalyzed using folded potentials based upon the density-independent M3Y effective interaction. Furthermore, reasonably successful reproduction of the data is obtained by Woods-Saxon-type optical model potentials. The radial sensitivity of the derived real potentials to the calculating elastic-scattering angular distributions has been investigated using the notch perturbation technique. The target mass dependence in real and imaginary volume integrals as well as total reaction cross sections are also investigated.

A recently derived dispersive optical model potential (DOMP) for ${}^{208}\mathrm{Pb}$ is extended to consider the nonlocality in the real potential and the shell gap in the definition of the nuclear imaginary potentials near the Fermi energy. The modified DOMP improves the simultaneous description of nucleon scattering on ${}^{208}\mathrm{Pb}$ and of the ${}^{208}\mathrm{Pb}$ particle-hole bound states. This potential is shown to give a very good description of nucleon scattering data on near-magic targets ${}^{206,207}\mathrm{Pb}$ and ${}^{209}\mathrm{Bi}$.

In the present work, we investigate the effects of short-range correlations (SRC) on the dimensionless deformability of the binary neutron system related to the GW170817 event. We implemented phenomenological SRC in a relativistic mean-field model in which the bulk parameters, namely, incompressibility ($K_0$), effective nucleon mass ratio ($m^{*}$), symmetry energy ($J$), and its slope ($L_0$), are independently controlled. Our results point out that the SRC favor the model to pass through the constraints, established by the LIGO/Virgo Collaboration, on the values of ${\mathrm{\Lambda }}_{1.4}$ and on the ${\mathrm{\Lambda }}_1\times {\mathrm{\Lambda }}_2$ region. We also found a clear linear correlation between ${\mathrm{\Lambda }}_{1.4}$ with $K_0$ and $L_0$ (increasing dependence), and with $m^{*}$ and $J$ (decreasing dependence). Finally, we also obtained compatible numbers for $R_{1.4}$ (model with and without SRC) in comparison with recent data from the neutron star interior composition explorer mission.

Background: The measurement of neutrino oscillations and exotic physics searches are important parts of the physics program in the near future, with new state-of-the-art experiments planned within the next decade. Future and modern experiments in these fields will make use of nuclear targets. Event generators (EGs) are software used in the analysis of neutrino oscillation experiments. EGs are used to predict kinematic observables for a range of neutrino energies. These simulations make use of simple models of nucleon dynamics. As such, they may fail to capture features of more rigorous theoretical calculations.

Purpose: This work compares EG performance to nuclear theory calculations by comparing observables generated in the two frameworks. We provide a common set of definitions between theory and experiment and assess the adequacy of the implementation of two nuclear physics models in EG simulations.

Method: Neutral-current quasielastic (NCQE) scattering events for neutrinos and antineutrinos on a ${}^{12}\mathrm{C}$ target are simulated with a specific EG, NEUT, used by the T2K experiment for its analysis. The simulated cross sections are compared to analytic calculations from nuclear theory within the factorization scheme. We compare the NEUT implementation of two different models on nuclear spectral functions: the relativistic Fermi gas (RFG) and the correlated basis spectral function (CBF) to analytic calculations of the same models in the factorization scheme. For both nuclear physics models, we compare the appearance of features in the distributions relevant to experimental analyses.

Results: The peak of the cross section $d\sigma /\left(d\mathrm{\Omega }d\omega \right)$ is consistent in energy transfer, $\omega$, for RFG and CBF simulations. Qualitatively, the shape of the simulated distribution is similar to the one obtained through theory calculations; however, there are some discrepancies between the theory calculations and the NEUT simulation.

Conclusions: While the EG simulations and analytic calculations with the same model of nuclear dynamics show similar overall features, there are still differences between the two. These results demonstrate the importance of benchmarking EGs so their nuclear physics implementations can be improved for the analysis of future experiments.

The $B\left(E2\right)$ value for the decay of the $2_1^{+}$ state of ${}^{16}\mathrm{C}$ to ground has been the subject of much discussion. The existing measurements extend over a large range, almost an order of magnitude, from 0.63 to $4.15e^2{\mathrm{fm}}^4$. Analyses assuming a simple model of two neutrons coupled to a ${}^{14}\mathrm{C}$ core give reasonable agreement but require the inclusion of a large effective charge for the neutrons. To assess this situation, a large-scale $(2+4)\hslash \omega$ shell-model calculation of ${}^{16}\mathrm{C}$ has been made from which the wave functions have been used to obtain the $B\left(E2\right)$ value. As a check, comparison is made with available data on the spectrum of ${}^{16}\mathrm{C}$ and intermediate-energy elastic proton scattering. It is found that with the new model a much smaller effective charge is needed, if at all, to explain the accepted $B\left(E2\right)$ value.

We report the measurements of the transverse ($P_x^{\prime }$) and longitudinal ($P_z^{\prime }$) components of the polarization transfer to a bound proton in carbon via the quasifree ${}^{12}\mathrm{C}(\vec{e},e^{\prime }\vec{p})$ reaction, over a wide range of missing momenta. We determine these polarization transfers separately for protons knocked out from the $s$ and $p$ shells. The electron-beam polarization was measured to determine the individual components with systematic uncertainties which allow a detailed comparison with theoretical calculations.

We describe the capture, fusion, fission, and evaporation residue formation cross sections of superheavy nuclei within the proposed earlier two-stage dynamical model. The approaching of the projectile nucleus to the target nucleus is described in the first stage of the model. In the second stage, the evolution of the system formed after the touching of the projectile and target nuclei is considered. The evolution of the system on both stages is described by the Langevin equations. The transport coefficients of these equations for the shape degrees of freedom are calculated within the microscopic linear-response theory. The mutual orientation of the colliding ions, the tunneling through the Coulomb barrier in the entrance channel and the shell effects in the potential energy on both stages of the calculations are taking into account. The obtained results are compared with the available experimental data and other theoretical predictions.