A chiral magnetic wave (CMW) is a gapless collective excitation of chiral charges along the direction of magnetic field in the quark-gluon plasma that arises from the triangle anomaly of QCD. We perform a reliable study of the CMW in a realistic simulation of heavy ion collisions, and find that the CMW contributions to the charge-dependent elliptic flow of pions, $\Delta v_2\equiv v_2\left({\pi }^{-}\right)-v_2\left({\pi }^{+}\right)$, linearly depending on the net charge asymmetry $A_{\pm }\equiv (N_{+}-N_{-})/(N_{+}+N_{-})$ with a positive slope $r$, is comparable to the recent experimental results from the Relativistic Heavy Ion Collider (RHIC). We identify a “freeze-out hole effect,” which is a direct consequence of the propagation of the CMW during the realistic evolution of the fireball, as the dominant physics effect responsible for a sizable contribution from the CMW to the slope parameter $r$, and emphasize that a proper treatment of the freeze-out condition is crucial in any reliable computation of the CMW contribution to the slope parameter $r$. We also implement a chiral phase transition effect in our study, which illustrates the sensitivity of the results to chiral phase transition temperature, and suggest that the CMW can be an important probe of the QCD chiral phase transition. Our results on the impact parameter dependence compare well with the RHIC experiments. We also give predictions for the Large Hadron Collider (LHC) energy.

Photons are a penetrating probe of the hot medium formed in heavy-ion collisions, but they are emitted from all collision stages. At photon energies below 2–3 GeV, the measured photon spectra are approximately exponential and can be characterized by their inverse logarithmic slope, often called the “effective temperature” $T_{\mathrm{eff}}$. Modeling the evolution of the radiating medium hydrodynamically, we analyze the factors controlling the value of the $T_{\mathrm{eff}}$ and how it is related to the evolving true temperature $T$ of the fireball. We find that at the energies available at the BNL Relativistic Heavy Ion Collider and the CERN Large Hadron Collider most photons are emitted from fireball regions with $T\sim T_{\mathrm{c}}$ near the quark-hadron phase transition, but that their effective temperature is significantly enhanced by strong radial flow. Although a very hot, high-pressure early collision stage is required for generating this radial flow, we demonstrate that the experimentally measured large effective photon temperatures $T_{\mathrm{eff}}>T_{\mathrm{c}}$, taken alone, do not prove that any electromagnetic radiation was actually emitted from regions with true temperatures well above $T_{\mathrm{c}}$. We explore tools that can help to provide additional evidence for the relative weight of photon emission from the early quark-gluon and late hadronic phases. We find that the recently measured centrality dependence of the total thermal photon yield requires a larger contribution from late emission than presently encoded in our hydrodynamic model.

We investigate the effects of the symmetry energy on nuclear “pasta” phases and the crust-core transition in neutron stars. We employ the relativistic mean-field approach and the coexisting phases method to study the properties of pasta phases presented in the inner crust of neutron stars. It is found that the slope of the nuclear symmetry energy at saturation density plays an important role in the crust-core transition and pasta phase properties. The correlation between the symmetry energy slope and the crust-core transition density obtained in this study is consistent with those obtained by other methods.

The shear viscosity of hot nuclear matter is investigated by using the mean free path method within the framework of the isospin-dependent quantum molecular dynamics model. Finite size nuclear sources at different density and temperature are initialized based on the Fermi-Dirac distribution. The results show that shear viscosity to entropy density ratio decreases with the increase of temperature and tends toward a constant value for $\rho \sim {\rho }_0$, which is consistent with the previous studies on nuclear matter formed during heavy-ion collisions. At $\rho \sim \frac{1}{2}{\rho }_0$, a minimum of $\eta /s$ is seen at around $T=10$ MeV and a maximum of the multiplicity of intermediate mass fragment ($M_{\text{IMF}}$) is also observed at the same temperature which is an indication of the liquid-gas phase transition.

We calculate the effective masses of neutrons and protons in dense nuclear matter within the microscopic Brueckner-Hartree-Fock many-body theory and study the impact on the neutrino emissivity processes of neutron stars. We compare results based on different nucleon-nucleon potentials and nuclear three-body forces. Useful parametrizations of the numerical results are given. We find substantial in-medium suppression of the emissivities, strongly dependent on the interactions.

Projectile-like fragments emerging from heavy ion collision have an excitation energy which is often labeled by a temperature. This temperature was recently calculated using a geometric model. We expand the geometric model to include dynamic effects using a transport model. The calculated temperatures agree quite well with values of temperature needed to fit experimental data.

We have evaluated the electron capture rates on ${}^{20}\mathrm{Ne}$, ${}^{20}\mathrm{F}$, ${}^{24}\mathrm{Mg}$, and ${}^{24}\mathrm{Na}$ and the $\beta$ decay rates for ${}^{20}\mathrm{F}$ and ${}^{24}\mathrm{Na}$ at temperature and density conditions relevant for the late-evolution stages of stars with $M=8M_{\odot }$–12$M_{\odot }$. The rates are based on recent experimental data and large-scale shell-model calculations. We show that the electron capture rates on ${}^{20}\mathrm{Ne}$ and ${}^{24}\mathrm{Mg}$ and the ${}^{20}\mathrm{F}$ and ${}^{24}\mathrm{Na}$ $\beta$-decay rates are based on data in this astrophysical range, except for the capture rate on ${}^{20}\mathrm{Ne}$, which we predict to have a dominating contribution from the second-forbidden transition between the ${}^{20}\mathrm{Ne}$ and ${}^{20}\mathrm{F}$ ground states in the density range ${log}_{10}\rho Y_e\left(\mathrm{g}{\mathrm{cm}}^{-3}\right)=9.3$–9.6. The dominance of a few individual transitions allows us to present the various rates by analytical expressions at the relevant astrophysical conditions. We also derive the screening corrections to the rates.

We compute the energy per particle of infinite symmetric nuclear matter from chiral N${}^3\mathrm{LO}$ (next-to-next-to-next-to-leading order) two-body potentials plus N${}^2\mathrm{LO}$ three-body forces. The low-energy constants of the chiral three-nucleon force that cannot be constrained by two-body observables are fitted to reproduce the triton binding energy and the ${}^3\mathrm{H}$-${}^3\mathrm{He}$ Gamow-Teller transition matrix element. In this way, the saturation properties of nuclear matter are reproduced in a parameter-free approach. The equation of state is computed up to third order in many-body perturbation theory, with special emphasis on the role of the third-order particle-hole diagram. The dependence of these results on the cutoff scale and regulator function is studied. We find that the inclusion of three-nucleon forces consistent with the applied two-nucleon interaction leads to a reduced dependence on the choice of the regulator only for lower values of the cutoff.

Previously it was noted in numerical calculations that a certain unitary $9j$ coefficient $$U(I,j)={\langle {\left(jj\right)}^{2j}{\left(jj\right)}^{2j}|{\left(jj\right)}^{2j}{\left(jj\right)}^{(2j-2)}\rangle }^I$$decreases with increasing $j$ and for fixed small $I$. The decrease is of the form $A{j}^m{e}^{-\alpha j}$. The exponential decay factor dominates. Analytically we also show, using the Stirling approximation, that $\alpha =4ln\left(2\right)$ and $m=\frac{3}{2}$.

Elastic scattering angular distributions of the radioactive weakly bound ${}^7\mathrm{Be}$ on ${}^{27}\mathrm{Al}$ have been measured at energies near the Coulomb barrier. The interaction optical potential is investigated by using different potentials. Total reaction cross sections have also been obtained.

The activation cross sections for production of ${}^{51}\mathrm{Cr}$, ${}^{52,54,56}\mathrm{Mn}$, ${}^{59}\mathrm{Fe}$, and ${}^{55,56,57,58}\mathrm{Co}$ radioisotopes in deuteron-induced reactions on natural Fe were measured at deuteron energies up to 20 MeV. Then, within an extended analysis of deuteron interactions with ${}^{\mathrm{nat}}$Fe, all processes from elastic scattering until the evaporation from fully equilibrated compound system have been taken into account. Following the available elastic-scattering data analysis that supports the deuteron optical potential for reaction cross sections calculations, increased attention is paid especially to the breakup (BU) mechanism and direct reactions (DR). The deuteron activation cross-section analysis is completed by consideration of the preequilibrium and compound-nucleus contributions, corrected for decrease of the total reaction cross section due to the leakage of the initial deuteron flux towards BU and DR processes. The overall agreement of the measured data and model calculations validates the description of nuclear mechanisms taken into account, particularly the strong effects of direct interactions that have still not been appropriately considered within previous deuteron activation evaluations.

The ${}^{241}\mathrm{Am}$($n$,$\gamma$) cross section has been measured at the n_TOF facility at CERN using deuterated benzene liquid scintillators, commonly known as C${}_6$D${}_6$ detectors, and time-of-flight spectrometry. The results in the resolved resonance range bring new constraints to evaluations below 150 eV, and the energy upper limit was extended from 150 to 320 eV with a total of 172 new resonances not present in current evaluations. The thermal capture cross section was found to be ${\sigma }_{th}=678\pm 68$ b, which is in good agreement with evaluations and most previous measurements. The capture cross section in the unresolved resonance region was extracted in the remaining energy range up to 150 keV, and found to be larger than current evaluations and previous measurements.

We analyze recently measured total reaction cross sections for ${}^{24–38}$Mg isotopes incident on ${}^{12}$C targets at 240 MeV/nucleon by using the folding model and antisymmetrized molecular dynamics (AMD). The folding model well reproduces the measured reaction cross sections, when the projectile densities are evaluated by the deformed Woods-Saxon (def-WS) model with AMD deformation. Matter radii of ${}^{24–38}$Mg are then deduced from the measured reaction cross sections by fine tuning the parameters of the def-WS model. The deduced matter radii are largely enhanced by nuclear deformation. Fully microscopic AMD calculations with no free parameter well reproduce the deduced matter radii for ${}^{24–36}$Mg, but still considerably underestimate them for ${}^{37,38}$Mg. The large matter radii suggest that ${}^{37,38}$Mg are candidates for deformed halo nucleus. AMD also reproduces other existing measured ground-state properties (spin parity, total binding energy, and one-neutron separation energy) of Mg isotopes. Neutron-number ($N$) dependence of deformation parameter is predicted by AMD. Large deformation is seen from ${}^{31}$Mg with $N=19$ to a drip-line nucleus ${}^{40}$Mg with $N=28$, indicating that both the $N=20$ and 28 magicities disappear. $N$ dependence of neutron skin thickness is also predicted by AMD.

A study is reported of the same- and opposite-sign charge-dependent azimuthal correlations with respect to the event plane in Au + Au collisions at $\sqrt{s_{{}_{NN}}}=200$ GeV. The charge multiplicity asymmetries between the up/down and left/right hemispheres relative to the event plane are utilized. The contributions from statistical fluctuations and detector effects were subtracted from the (co-)variance of the observed charge multiplicity asymmetries. In the mid- to most-central collisions, the same- (opposite-) sign pairs are preferentially emitted in back-to-back (aligned on the same-side) directions. The charge separation across the event plane, measured by the difference, $\Delta$, between the like- and unlike-sign up/down-left/right correlations, is largest near the event plane. The difference is found to be proportional to the event-by-event final-state particle ellipticity (via the observed second-order harmonic $v_2^{\mathrm{obs}}$), where $\Delta =[1.3\pm 1.4{\left(\mathrm{stat}\right)}_{-1.0}^{+4.0}\left(\mathrm{syst}\right)]\times {10}^{-5}+[3.2\pm 0.2{\left(\mathrm{stat}\right)}_{-0.3}^{+0.4}\left(\mathrm{syst}\right)]\times {10}^{-3}{v}_2^{\mathrm{obs}}$ for 20–40% Au + Au collisions. The implications for the proposed chiral magnetic effect are discussed.

In this work we investigate protoneutron star properties within a modified version of the quark-meson coupling (QMC) model that incorporates an $\omega \text{−}\rho$ interaction plus kaon condensed matter at finite temperature. Fixed entropy and trapped neutrinos are taken into account. Our results are compared with the ones obtained with the GM1 parametrization of the nonlinear Walecka model for similar values of the symmetry energy slope. Contrary to GM1, within the QMC model the formation of low mass black holes during cooling are not probable. It is shown that the evolution of the protoneutron star may include the melting of the kaon condensate driven by the neutrino diffusion, followed by the formation of a second condensate after cooling. The signature of this complex process could be a neutrino signal followed by a gamma ray burst. We have seen that both models can, in general, describe very massive stars.

Comprehensive measurements of the excitation energy and spin-parity assignments for states in ${}^{31}\mathrm{S}$ are presented, from the first excited state, up to energies relevant for the ${}^{30}\mathrm{P}$($p$,$\gamma$)${}^{31}\mathrm{S}$ reaction in ONe novae. This reaction rate strongly influences heavy element abundances in novae ejecta. States in ${}^{31}\mathrm{S}$ are paired with their ${}^{31}\mathrm{P}$ analogues using $\gamma$ rays detected with the Gammasphere detector array following the ${}^{28}\mathrm{Si}$(${}^4\mathrm{He}$, $n$) fusion-evaporation reaction. The evolution of mirror energy differences is explored and the results are compared with new shell-model calculations. The excellent agreement observed in this work between experimental data and shell-model calculations provides confidence in using computed estimates in situations where experimental data are unavailable.

Magnetars are compact stars, which are observationally determined to have very strong surface magnetic fields of the order of ${10}^{14}–{10}^{15}$ G. The center of the star can potentially have a magnetic field several orders of magnitude larger. We study the effect of the field on the mass and shape of such a star. In general, we assume a nonuniform magnetic field inside the star, which varies with density. The magnetic energy and pressure as well as the metric are expanded as multipoles in spherical harmonics up to the quadrupole term. Solving the Einstein equations for the gravitational potential, one obtains the correction terms as functions of the magnetic field. Using a nonlinear model for the hadronic EoS the excess mass and change in equatorial radius of the star due to the magnetic field are quite significant if the surface field is ${10}^{15}$ G and the central field is about ${10}^{18}$ G. For a value of the central magnetic field strength of $1.75\times {10}^{18}$ G, we find that both the excess mass and the equatorial radius of the star changes by about $3–4\%$ compared to the spherical solution.

The thermal evolution of a few thermodynamic properties of the nuclear surface like its thermodynamic potential energy, entropy, and the symmetry free energy are examined for both semi-infinite nuclear matter and finite nuclei. The Thomas-Fermi model is employed. Three Skyrme interactions, namely, SkM${}^{*}$, SLy4, and SK255, are used for the calculations to gauge the dependence of the nuclear surface properties on the energy density functionals. For finite nuclei, the surface observables are computed from a global liquid-drop-inspired fit of the energies and free energies of a host of nuclei covering the entire periodic table. The hot nuclear system is modeled in a subtracted Thomas-Fermi framework. Compared to semi-infinite nuclear matter, substantial changes in the surface symmetry energy of finite nuclei are indicated; surface thermodynamic potential energies for the two systems are, however, not too different. Analytic expressions to fit the temperature and asymmetry dependence of the surface thermodynamic potential of semi-infinite nuclear matter and the temperature dependence of the surface free energy of finite nuclei are given.