We argue that relativistic hydrodynamics is able to make robust predictions for soft particle production in Xe+Xe collisions at the CERN Large Hadron Collider (LHC). The change of system size from Pb+Pb to Xe+Xe provides a unique opportunity to test the scaling laws inherent to fluid dynamics. Using event-by-event hydrodynamic simulations, we make quantitative predictions for several observables: mean transverse momentum, anisotropic flow coefficients, and their fluctuations. Results are shown as a function of collision centrality.

The quantum mechanical Beth-Uhlenbeck (BU) approach for repulsive hard-core interactions between baryons is applied to the thermodynamics of a hadron gas. The second virial coefficient $a_2$—the “excluded volume” parameter—calculated within the BU approach is found to be temperature dependent, and it differs dramatically from the classical excluded volume (EV) model result. At temperatures $T=100–200$ MeV, the widely used classical EV model underestimates the EV parameter for nucleons at a given value of the nucleon hard-core radius by large factors of 3–4. Previous studies, which employed the hard-core radii of hadrons as an input into the classical EV model, have to be re-evaluated using the appropriately rescaled EV parameters. The BU approach is used to model the repulsive baryonic interactions in the hadron resonance gas (HRG) model. Lattice data for the second- and fourth-order net baryon susceptibilities are described fairly well when the temperature dependent BU baryonic excluded volume parameter corresponds to nucleon hard-core radii of $r_c=0.25–0.3$ fm. Role of the attractive baryonic interactions is also considered. It is argued that HRG model with a constant baryon-baryon EV parameter $v_{NN}\simeq 1{\mathrm{fm}}^3$ provides a simple yet efficient description of baryon-baryon interaction in the crossover temperature region.

Several states of proton-unbound isotopes ${}^{30}\mathrm{Ar}$ and ${}^{29}\mathrm{Cl}$ were investigated by measuring their in-flight decay products, ${}^{28}\mathrm{S}$ + proton + proton and ${}^{28}\mathrm{S}$ + proton, respectively. A refined analysis of ${}^{28}\mathrm{S}$-proton angular correlations indicates that the ground state of ${}^{30}\mathrm{Ar}$ is located at $2.{45}_{-0.10}^{+0.05}$ MeV above the two-proton emission threshold. The investigation of the decay mechanism of the ${}^{30}\mathrm{Ar}$ ground state demonstrates that it has the transition dynamics. In the “transitional” region, the correlation patterns of the decay products present a surprisingly strong sensitivity to the two-proton decay energy of the ${}^{30}\mathrm{Ar}$ ground state and the one-proton decay energy as well as the one-proton decay width of the ${}^{29}\mathrm{Cl}$ ground state. The comparison of the experimental ${}^{28}\mathrm{S}$-proton angular correlations with those resulting from Monte Carlo simulations of the detector response illustrates that other observed ${}^{30}\mathrm{Ar}$ excited states decay by sequential emission of protons via intermediate resonances in ${}^{29}\mathrm{Cl}$. Based on the findings, the decay schemes of the observed states in ${}^{30}\mathrm{Ar}$ and ${}^{29}\mathrm{Cl}$ were constructed. For calibration purposes and for checking the performance of the experimental setup, decays of the previously known states of a two-proton emitter ${}^{19}\mathrm{Mg}$ were remeasured. Evidences for one new excited state in ${}^{19}\mathrm{Mg}$ and two unknown states in ${}^{18}\mathrm{Na}$ were found.

Following the reports of candidate chiral doublet bands observed in odd-$A$ cesium isotopes, the triaxial deformations with corresponding configuration and the possible multiple chiral doublet ($\mathrm{M}\chi \mathrm{D}$) phenomenon in ${}^{125,127,129,131}\mathrm{Cs}$ are investigated within the adiabatic and configuration-fixed constrained triaxial relativistic mean-field (RMF) calculations. The existence of the $\mathrm{M}\chi \mathrm{D}$ phenomenon in ${}^{125,129,131}\mathrm{Cs}$ is demonstrated and expected based on different high-$j$ particle-hole configurations and triaxial deformations.

Recently the effect of nucleon shadowing on the Monte Carlo–Glauber initial condition was studied and its role on the centrality dependence of elliptic flow ($v_2$) and fluctuations in initial eccentricity for different colliding nuclei were explored. It was found that the results with shadowing effects are closer to the QCD-based dynamical model as well as to the experimental data. Inspired by this outcome, in this work we study the transverse momentum ($p_T$) spectra and elliptic flow of thermal photons for $\mathrm{Au}+\mathrm{Au}$ collisions at the BNL Relativisitic Heavy Ion Collider and $\mathrm{Pb}+\mathrm{Pb}$ collisions at the CERN Large Hadron Collider by incorporating the shadowing effects in deducing the initial energy density profile required to solve the relativistic hydrodynamical equations. We find that the thermal photon spectra remain almost unaltered; however, the elliptic flow of photons is found to be enhanced significantly due to shadowing effects.

With the help of effective Lagrangian densities of strange hadrons, we calculated the kaon relaxation time from several loop and scattering diagrams at tree level, which basically represent contributions from $1\leftrightarrow 2$ and $2\leftrightarrow 2$ types of collisions. Using the total relaxation time of a kaon, the shear viscosity and electrical conductivity of this kaon component have been estimated. The high temperature, close to transition temperature, where the kaon relaxation time is lower than the lifetime of Relativistic Heavy Ion Collider or Large Hadron Collider matter may be the only relevant domain for this component to contribute in hadronic dissipation. Our results suggest that the kaon can play an important role in the enhancement of shear viscosity and electrical conductivity of hadronic matter near the transition temperature.

We have measured the half-life of ${}^{30}\mathrm{S}$, the parent of a superallowed $0^{+}\to 0^{+}\beta$ transition, to a high precision using very pure sources and a $4\pi$ proportional gas counter to detect the decay positrons. Our result for the half-life is 1.179 92(34) s. As a by-product of this measurement, we determine the half-life of its daughter, ${}^{30}\mathrm{P}$, to be 2.501(2) min.

Microscopic signatures of nuclear ground-state shape-phase transitions in odd-mass Eu isotopes are explored starting from excitation spectra and collective wave functions obtained by diagonalization of a core-quasiparticle coupling Hamiltonian based on energy density functionals. As functions of the physical control parameter—the number of nucleons—theoretical low-energy spectra, two-neutron separation energies, charge isotope shifts, spectroscopic quadrupole moments, and $E2$ reduced transition matrix elements accurately reproduce available data and exhibit more-pronounced discontinuities at neutron number $N=90$ compared with the adjacent even-even Sm and Gd isotopes. The enhancement of the first-order quantum phase transition in odd-mass systems can be attributed to a shape polarization effect of the unpaired proton which, at the critical neutron number, starts predominantly coupling to Gd core nuclei that are characterized by larger quadrupole deformation and weaker proton pairing correlations compared with the corresponding Sm isotopes.

Based on the beyond-mean-field Skyrme-Hartree-Fock model, the up-to-date Skyrme-type $N\mathrm{\Lambda }$ interaction, SLL4, is used to investigate the properties of ${}_{\mathrm{\Lambda }}{}^9\mathrm{Be}$ comprehensively. Energies of different configurations, such as ${}^8\mathrm{Be}\otimes \mathrm{\Lambda }\left[000\right]1/2^{+}, {}^8\mathrm{Be}\otimes \mathrm{\Lambda }\left[110\right]1/2^{-}, {}^8\mathrm{Be}\otimes \mathrm{\Lambda }\left[101\right]3/2^{-}$, and ${}^8\mathrm{Be}\otimes \mathrm{\Lambda }\left[101\right]1/2^{-}$ are given and used to study the effects of $\mathrm{\Lambda }$ occupying different orbitals. The calculated energy spectra, including both positive- and negative-parity levels, are given and compared to the experimental data. The observed positive-parity spin doublets ($3/2^{+},5/2^{+}$) are successfully reproduced, but the energy difference needs further investigation. The two well-known band structures corresponding to the genuine hypernuclear states and the ${}^9\mathrm{Be}$-analog states are also obtained and compared with the observed ones. The shrinkage effect of $\mathrm{\Lambda }$ occupying $\mathrm{\Lambda }\left[000\right]1/2^{+}$ is investigated through the density distributions of nuclear core. And finally, the $E2$ transition rates are given and compared with the observed data and with the results of the hypernuclear particle-rotor model. Properties of ${}_{\mathrm{\Lambda }\mathrm{\Lambda }}{}^{10}\mathrm{Be}$ are also studied to show the completeness of this current model.

Precise knowledge of the branching ratio in the α decay of ${}^{210}\mathrm{Po}$ is important for accurate measurement of the ${}^{209}\mathrm{Bi}(n,\gamma ){}^{210\mathrm{g}}\mathrm{Bi}$ cross section, the reaction involved in the termination of the astrophysical $s$ process. The branching ratio was determined from independent measurements of α and γ spectra of bismuth samples simultaneously irradiated by neutrons near the core of the Soreq research reactor (IRR1). The branching ratio was found to be $\left(1.15\pm 0.09\right)\times {10}^{-5}$, consistent with the results of several measurements performed six decades ago. As a by-product value the ${}^{209}\mathrm{Bi}(n,\gamma ){}^{210\mathrm{g}}\mathrm{Bi}$ thermal cross section was measured to be $21.6\pm 1.1$ mb.

The nuclear matrix elements (NMEs) of the neutrinoless and two-neutrino double-$\beta$ decays of ${}^{48}\mathrm{Ca}$ are calculated by the quasiparticle random-phase approximation (QRPA) with emphasis on the consistency examinations of this calculation method. The main new examination points are the consistency of two ways to treat the intermediate-state energies in the two-neutrino double-$\beta$ NME and comparison with the experimental charge-exchange strength functions obtained from ${}^{48}\mathrm{Ca}(p,n)$ and ${}^{48}\mathrm{Ti}(n,p)$ reactions. No decisive problem preventing use of the QRPA approach is found. The obtained neutrinoless double-$\beta$ NME adjusted by the ratio of the effective and bare axial-vector current couplings is lowest in those calculated by different groups and close to one of the QRPA values obtained by another group.

I have examined mirror energy differences between $2s_{1/2}, 1d_{5/2}$, and $1f_{7/2}$ single-particle states in neutron-excess light nuclei and their proton-excess mirrors. I expand on the earlier $2s_{1/2}$ treatment. For $1d_{5/2}$, I find that 11 such cases can be fitted by a simple expression, which I then use to compute the energies of other $1d_{5/2}$ states. Agreement with experimental values is good. Agreement is found to be even better for $1f_{7/2}$ states.

In the analysis of transfer reaction data to extract nuclear structure information the choice of input parameters to the reaction model such as distorting potentials and overlap functions has a significant impact. In this paper we consider a set of data for the ($d,t$) and ($d,{}^3\mathrm{He}$) reactions on ${}^{14,16,18}\mathrm{O}$ as a well-delimited subject for a study of the sensitivity of such analyses to different choices of distorting potentials and overlap functions with particular reference to a previous investigation of the variation of valence nucleon correlations as a function of the difference in nucleon separation energy $\mathrm{\Delta }S=|S_p-S_n|$ [Phys. Rev. Lett. 110, 122503 (2013)].

The wounded nucleon and quark emission functions are extracted for different centralities in $d+\mathrm{Au}$ collisions at $\sqrt{s}=200\text{GeV}$ using Monte Carlo simulations and experimental data. The shape of the emission function depends on centrality in the wounded nucleon model, whereas it is practically universal (within uncertainties) in the wounded quark model. Predictions for $d{N}_{ch}/d\eta$ distributions in $p+\mathrm{Au}$ and ${}^3\mathrm{He}+\mathrm{Au}$ collisions are presented.

We have measured the capture-fission excitation functions for the reaction of stable ${}^{39}\mathrm{K}$ and radioactive ${}^{46}\mathrm{K}$ with ${}^{181}\mathrm{Ta}$ using the ReA3 facility at the National Superconducting Cyclotron Laboratory. In addition the capture-fission excitation function for the ${}^{39}\mathrm{K}+{}^{181}\mathrm{Ta}$ reaction was measured at Australian National University . The capture cross sections for the ${}^{46}\mathrm{K}+{}^{181}\mathrm{Ta}$ reaction are larger than those for the ${}^{39}\mathrm{K}$ induced reactions in the near barrier region although the reduced excitation functions for the two reactions do not indicate any fundamental differences between the reactions. The results of the measurements are compared to modern phenomenological models and microscopic time-dependent Hartree-Fock calculations. The implications of these measurements for the synthesis of heavy nuclei at radioactive beam facilities are discussed.

Quasielastic neutrino scattering is an important aspect of the experimental program to study fundamental neutrino properties including neutrino masses, mixing angles, mass hierarchy, and charge-conjugation parity (CP)- violating phase. Proper interpretation of the experiments requires reliable theoretical calculations of neutrino-nucleus scattering. In this paper we present calculations of response functions and cross sections by neutral-current scattering of neutrinos off ${}^{12}\mathrm{C}$. These calculations are based on realistic treatments of nuclear interactions and currents, the latter including the axial, vector, and vector-axial interference terms crucial for determining the difference between neutrino and antineutrino scattering and the CP-violating phase. We find that the strength and energy dependence of two-nucleon processes induced by correlation effects and interaction currents are crucial in providing the most accurate description of neutrino-nucleus scattering in the quasielastic regime.

In this paper a new local mass relation is constructed for isobaric analogue states of four relating neighboring nuclei. The standard deviation from a linear fit of experimental data is 20–70 keV. The systematics of the local mass relation is discussed in terms of an empirical Coulomb energy formula and the isobaric multiplet mass equation. The local relation for nuclei in the $pf$ shell is studied in the framework of the microscopic shell model. The results demonstrate the key roles played by the Coulomb interaction and an effective isospin-nonconserving nucleon-nucleon interaction in our new mass relation.

Kinetic equations for fermions and bosons are solved numerically in the relaxation-time approximation for the case of one-dimensional boost-invariant geometry. Fermions are massive and carry baryon number, while bosons are massless. The conservation laws for the baryon number, energy, and momentum lead to two Landau matching conditions, which specify the coupling between the fermionic and bosonic sectors and determine the proper-time dependence of the effective temperature and baryon chemical potential of the system. The numerical results illustrate how a nonequilibrium mixture of fermions and bosons approaches hydrodynamic regime described by the Navier-Stokes equations with appropriate forms of the kinetic coefficients. The shear viscosity of a mixture is the sum of the shear viscosities of fermion and boson components, while the bulk viscosity is given by the formula known for a gas of fermions, however, with the thermodynamic variables characterising the mixture. Thus, we find that massless bosons contribute in a nontrivial way to the bulk viscosity of a mixture, provided fermions are massive. We further observe the hydrodynamization effect, which takes place earlier in the shear sector than in the bulk one. The numerical studies of the ratio of the longitudinal and transverse pressures show, to a good approximation, that it depends on the ratio of the relaxation and proper times only. This behavior is connected with the existence of an attractor solution for conformal systems.

The ${}^1\mathrm{H}\left(e,e^{\prime }{K}^{+}\right)\mathrm{\Lambda }$ reaction was studied as a function of the Mandelstam variable $-t$ using data from the E01-004 (FPI-2) and E93-018 experiments that were carried out in Hall C at the 6 GeV Jefferson Laboratory. The cross section was fully separated into longitudinal and transverse components, and two interference terms at four-momentum transfers $Q^2$ of 1.00, 1.36, and 2.$07{\mathrm{GeV}}^2$. The kaon form factor was extracted from the longitudinal cross section using the Regge model by Vanderhaeghen et al. [Phys. Rev. C 57, 1454 (1998)]. The results establish the method, previously used successfully for pion analyses, for extracting the kaon form factor. Data from 12 GeV Jefferson Laboratory experiments are expected to have sufficient precision to distinguish between theoretical predictions, for example, recent perturbative QCD calculations with modern parton distribution amplitudes. The leading-twist behavior for light mesons is predicted to set in for values of $Q^2$ between 5 and $10{\mathrm{GeV}}^2$, which makes data in the few-GeV regime particularly interesting. The $Q^2$ dependence at fixed $x$ and $-t$ of the longitudinal cross section that we extracted seems consistent with the QCD factorization prediction within the experimental uncertainty.

Metamodeling for the nucleonic equation of state (EOS), inspired from a Taylor expansion around the saturation density of symmetric nuclear matter, is proposed and parameterized in terms of the empirical parameters. The present knowledge of nuclear empirical parameters is first reviewed in order to estimate their average values and associated uncertainties, and thus defining the parameter space of the metamodeling. They are divided into isoscalar and isovector types, and ordered according to their power in the density expansion. The goodness of the metamodeling is analyzed against the predictions of the original models. In addition, since no correlation among the empirical parameters is assumed a priori, all arbitrary density dependences can be explored, which might not be accessible in existing functionals. Spurious correlations due to the assumed functional form are also removed. This meta-EOS allows direct relations between the uncertainties on the empirical parameters and the density dependence of the nuclear equation of state and its derivatives, and the mapping between the two can be done with standard Bayesian techniques. A sensitivity analysis shows that the more influential empirical parameters are the isovector parameters $L_{\mathrm{sym}}$ and $K_{\mathrm{sym}}$, and that laboratory constraints at supersaturation densities are essential to reduce the present uncertainties. The present metamodeling for the EOS for nuclear matter is proposed for further applications in neutron stars and supernova matter.