We analyze hadrochemical freeze-out in central Pb + Pb collisions at CERN SPS energies, employing the hybrid version of the Ultrarelativistic Quantum Molecular Dynamics model, which describes the transition from a hydrodynamic stage to hadrons by the Cooper-Frye mechanism, and matches to a final hadron-resonance cascade. We fit the results both before and after the cascade stage using the statistical model to assess the effect of the cascade phase. We observe a strong effect on antibaryon yields except anti-$\Omega$, resulting in a shift in $T$ and ${\mu }_B$ of the freeze-out curve. We discuss indications of a similar effect in SPS and RHIC data, and propose a method to recover the bulk hadron freeze-out conditions.

Scattering of protons of several hundred MeV is a promising new spectroscopic tool for the study of electric dipole strength in nuclei. A case study of ${}^{208}$Pb shows that, at very forward angles, $J^{\pi }=1^{-}$ states are strongly populated via Coulomb excitation. A separation from nuclear excitation of other modes is achieved by a multipole decomposition analysis of the experimental cross sections based on theoretical angular distributions calculated within the quasiparticle-phonon model. The $B\left(E1\right)$ transition strength distribution is extracted for excitation energies up to 9 MeV; that is, in the region of the so-called pygmy dipole resonance (PDR). The Coulomb-nuclear interference shows sensitivity to the underlying structure of the $E1$ transitions, which allows for the first time an experimental extraction of the electromagnetic transition strength and the energy centroid of the PDR.

In order to describe heavy-ion fusion reactions around the Coulomb barrier with an actinide target nucleus, we propose a model which combines the coupled-channels approach and a fluctuation-dissipation model for dynamical calculations. This model takes into account couplings to the collective states of the interacting nuclei in the penetration of the Coulomb barrier and the subsequent dynamical evolution of a nuclear shape from the contact configuration. In the fluctuation-dissipation model with a Langevin equation, the effect of nuclear orientation at the initial impact on the prolately deformed target nucleus is considered. Fusion-fission, quasifission, and deep quasifission are separated as different Langevin trajectories on the potential energy surface. Using this model, we analyze the experimental data for the mass distribution of fission fragments (MDFF) in the reactions of ${}^{34,36}$S + ${}^{238}$U and ${}^{30}$Si + ${}^{238}$U at several incident energies around the Coulomb barrier. We find that the time scale in the quasifission as well as the deformation of fission fragments at the scission point are different between the ${}^{30}$Si + ${}^{238}$U and ${}^{36}$S + ${}^{238}$U systems, causing different mass asymmetries of the quasifission.

We have measured the neutron capture cross sections of the stable magnesium isotopes ${}^{24,25,26}$Mg in the energy range of interest to the $s$ process using the neutron time-of-flight facility n_TOF at CERN. Capture events from a natural metal sample and from samples enriched in ${}^{25}$Mg and ${}^{26}$Mg were recorded using the total energy method based on C${}_6$${}^2$H${}_6$ detectors. Neutron resonance parameters were extracted by a simultaneous resonance shape analysis of the present capture data and existing transmission data on a natural isotopic sample. Maxwellian-averaged capture cross sections for the three isotopes were calculated up to thermal energies of 100 keV and their impact on $s$-process analyses was investigated. At 30 keV the new values of the stellar cross section for ${}^{24}$Mg, ${}^{25}$Mg, and ${}^{26}$Mg are 3.8$\pm$0.2 mb, 4.1$\pm$0.6 mb, and 0.14$\pm$0.01 mb, respectively.

The neutron capture cross section of ${}^{237}$Np was measured between 0.7 and 500 eV at the CERN n_TOF facility using the 4$\pi$ BaF${}_2$ Total Absorption Calorimeter. The experimental capture yield was extracted minimizing all the systematic uncertainties and was analyzed together with the most reliable transmission data available using the sammy code. The result is a complete set of individual as well as average resonance parameters [$D_0=0.56\left(2\right)$ eV, $\langle {\Gamma }_{\gamma }\rangle =40.9\left(18\right)$ meV, ${10}^4{S}_0=0.98\left(6\right)$, $R^{\prime }=9.8\left(6\right)$ fm]. The capture cross section obtained in this work is in overall agreement with the evaluations and the data of Weston and Todd [Nucl. Sci. Eng. 79, 184 (1981)], thus showing sizable differences with respect to previous data from Scherbakov et al. [J. Nucl. Sci. Technol. 42, 135 (2005)] and large discrepancies with data Kobayashi et al. [J. Nucl. Sci. Technol. 39, 111 (2002)]. The results indicate that a new evaluation combining the present capture data with reliable transmission data would allow reaching an accuracy better than 4$\%$, in line with the uncertainty requirements of the nuclear data community for the design and operation of current and future nuclear devices.

The upcoming $p+\text{Pb}$ run at the Large Hadron Collider (LHC) will probe the nuclear gluon distribution at very small Bjorken $x$ (from $x\sim {10}^{-4}$ at midrapidity down to $x\sim {10}^{-6}$ in the proton fragmentation region) and will allow testing of approaches based on parton saturation. Here, we present the predictions of the Kharzeev-Levin-Nardi model for hadron multiplicities and multiplicity distributions in $p+\text{Pb}$ collisions at a center-of-mass energy of 4.4 TeV. We also compare the model to the existing $pp$, $dA$, and $AA$ data from the Relativistic Heavy Ion Collider and LHC.

A new analysis of the modern astrophysical $S$ factors for the direct-capture ${}^3\mathrm{He}(\alpha ,\gamma ){}^7\mathrm{Be}$ reaction, precisely measured in recent works [B.S. Nara Singh et al., Phys. Rev. Lett. 93, 262503 (2004); D. Bemmerer et al., Phys. Rev. Lett. 97, 122502 (2006);F. Confortola et al., Phys. Rev. C 75, 065803 (2007), Gy. Gyürky et al., Phys. Rev. C 75, 035805 (2007), T. A. D. Brown et al., Phys. Rev. C 76, 055801 (2007), and A. Di Leva, et al., Phys. Rev. Lett. 102, 232502 (2009)], has been carried out within the modified two-body potential approach. New estimates are obtained for the “indirectly determined” values of the asymptotic normalization constants and the respective nuclear vertex constants for ${}^3\mathrm{He}+\alpha \to {}^7\mathrm{Be}$(g.s.) and ${}^3\mathrm{He}+\alpha \to {}^7\mathrm{Be}$(0.429 MeV) as well as the astrophysical $S$ factors $S_{34}\left(E\right)$ at $E\le 90$ keV, including $E=0$. The values of asymptotic normalization constants have been used to obtain the values of the ratio of the $\alpha$-particle spectroscopic factors for the mirror (${}^7\mathrm{Li}{}^7\mathrm{Be}$) pair.

The lifetimes of the first 2${}^{+}$ states in the neutron-deficient ${}^{76,78}$Sr isotopes were measured using a unique combination of the $\gamma$-ray line-shape method and two-step nucleon exchange reactions at intermediate energies. The transition rates for the 2${}^{+}$ states were determined to be $B(\mathrm{E}2;2^{+}\to 0^{+})=2220\left(270\right)$ $e^2$fm${}^4$ for ${}^{76}$Sr and 1800(250) $e^2$fm${}^4$ for ${}^{78}$Sr, corresponding to large deformation of ${\beta }_2$ $=$ 0.45(3) for ${}^{76}$Sr and 0.40(3) for ${}^{78}$Sr. The present data provide experimental evidence for mutually enhanced collectivity that occurs at $N$ $=$ $Z$ $=$ 38. The systematic behavior of the excitation energies and $B\left(\mathrm{E}2\right)$ values indicates a signature of shape coexistence in ${}^{76}$Sr, characterizing ${}^{76}$Sr as one of most deformed nuclei with an unusually reduced $E$(4${}^{+}$)$/E$(2${}^{+}$) ratio.

Dynamics of spontaneous symmetry breaking and fluctuations in the Lipkin-Meshkov-Glick model are investigated in a stochastic mean-field approach. Different from the standard mean-field approach, in the stochastic approach, initial state fluctuations are incorporated. In weak coupling, the approach perfectly reproduces the exact quantal dynamics. On the other hand, for increasing coupling strength, above the symmetry breaking threshold, the approach provides descriptions of gross properties (i.e., time-averaged behavior) of the exact quantal evolution.

Within the frameworks of the nonrelativistic plane wave Born approximation (PWBA), the analytical formulas for cross sections of $E1$–$E3$ and $M1$–$M2$ excitation of nuclei to the low-energy isomeric state as a result of inelastic scattering of nonrelativistic electrons are derived in the present work. The PWBA cross section of $E1$ excitation of isomer ${}^{181}{\text{Ta}}^m$ (9/2${}^{-}$, 6.237 keV) by electrons appeared to be two orders less than that one used in a number of works for calculation of isomeric nuclei yield under exposure of ${}^{181}$Ta-target hot dense laser plasma. To test the PWBA method we have calculated excitation cross sections of the nuclei ${}^{181}$Ta, ${}^{110}$Ag, ${}^{169}$Tm, and ${}^{201}$Hg in a relativistic version of the Hartree-Fock-Slater method. It was established that the PWBA method overestimates $E1$ cross sections and underestimates $E2$ and $M1$ cross sections.

The existing evaluations of the ${}^{243}$Am neutron-induced fission cross section have been questioned by recent measurements performed at the GNEISS facility. In the neutron energy range from 1 to 6 MeV, the GNEISS data present deviations of more than 15$\%$ with respect to the evaluations. In order to solve this problem, we have measured this cross section in reference to three different standard cross sections. The first standard reaction used corresponds to the neutron on proton elastic scattering cross section, which is known with a precision better than 0.5$\%$ over a wide neutron-energy range of 1 meV to 20 MeV. The other two experiments were conducted in reference to the ${}^{235}$U(n, f) and ${}^{238}$U(n, f) reactions. The comparison between these three standard reactions ensures that systematic parameters have been correctly evaluated. Moreover, a sensitivity analysis of parameters and correlations of parameters is described and a complete variance-covariance matrix of the measurements is presented and discussed.

I show that fluctuations in elliptic anisotropy in heavy-ion collisions can be used to significantly reduce the contribution of transverse-momentum conservation, and of all background effects independent of the orientation of the reaction plane, from an observable of the chiral magnetic effect. I argue that for a given impact parameter, the magnetic field is approximately independent of the fluctuating shape of the fireball.

We present results from the KamLAND-Zen double-beta decay experiment based on an exposure of 77.6 days with 129 kg of ${}^{136}$Xe. The measured two-neutrino double-beta decay half-life of ${}^{136}$Xe is $T_{1/2}^{2\nu }=2.38\pm 0.02\left(\mathrm{stat}\right)\pm 0.14\left(\mathrm{syst}\right)\times {10}^{21}$ yr, consistent with a recent measurement by EXO-200. We also obtain a lower limit for the neutrinoless double-beta decay half-life, $T_{1/2}^{0\nu }>5.7\times {10}^{24}$ yr at 90$\%$ confidence level (C. L.), which corresponds to almost a fivefold improvement over previous limits.

The nuclear equation of state and incompressibility are studied in a model with correlations. We first consider a Hartree solution and then add one-particle–one-hole (1p-1h) and two-particle–two-hole (2p-2h) admixtures into the wave function using a separable monopole-monopole interaction $\lambda r^2\left(i\right)r^2\left(j\right)$ which induces giant monopole vibrations. Stable and unstable points arise in the nuclear equation of state as a function of the oscillator size parameter from pure 1p-1h admixtures. Addition of 2p-2h admixtures leads to one stable point. However, the incompressibility is found to be quite different from the Hartree case with 1p-1h admixtures, even with 2p-2h states included.

The model dependence of the predictions of nucleon resonances with hidden charm is investigated. We consider several coupled-channel models which are derived from relativistic quantum field theory by using (1) a unitary transformation method and (2) the three-dimensional reductions of the Bethe-Salpeter equation. With the same vector-meson exchange mechanism, we find that all models give very narrow molecularlike nucleon resonances with hidden charm in the mass range of 4.3 $<M_R<$ 4.5 GeV, consistent with the previous predictions.

The self-consistent random-phase approximation, based on the framework of relativistic energy density functionals, is employed in the study of isovector and isoscalar dipole response in ${}^{68}\mathrm{Ni},{}^{132}\mathrm{Sn}$, and ${}^{208}\mathrm{Pb}$. The evolution of pygmy dipole states (PDSs) in the region of low excitation energies is analyzed as a function of the density dependence of the symmetry energy for a set of relativistic effective interactions. The occurrence of PDSs is predicted in the response to both the isovector and the isoscalar dipole operators, and its strength is enhanced with the increase in the symmetry energy at saturation and the slope of the symmetry energy. In both channels, the PDS exhausts a relatively small fraction of the energy-weighted sum rule but a much larger percentage of the inverse energy-weighted sum rule. For the isovector dipole operator, the reduced transition probability $B\left(E1\right)$ of the PDSs is generally small because of pronounced cancellation of neutron and proton partial contributions. The isoscalar-reduced transition amplitude is predominantly determined by neutron particle-hole configurations, most of which add coherently, and this results in a collective response of the PDSs to the isoscalar dipole operator.

We investigate mass shifts of charmonia driven by change of the gluon condensate below but near transition temperatures at finite baryonic chemical potential. Extending previous prescription on the relation between gluon condensates and thermodynamic quantities, we model the gluon condensates of hadronic matter at finite temperature and baryonic chemical potential such that the scalar gluon condensate fits with the latest lattice QCD data. By making use of the QCD sum rule and the second-order Stark effect, we find that the smoother transition in the full QCD can lead to moderate mass shifts of charmonia even below the transition temperature. We also find larger mass shift at fixed temperature as chemical potential increases. Existing data on charmonium-charmonium ratio is found to be consistent with the statistical hadronization scenario, including the obtained mass shift.

We study the effects of the equation of state on the nuclear suppression of heavy flavors in quark gluon plasma and estimate the initial entropy density of the system produced in Au + Au collision at the highest Relativistic Heavy Ion Collider (RHIC) energy. For this purpose the experimental data on the charged-particle multiplicity and the nuclear suppression of single-electron spectra originating from the semileptonic decays of open charm and beauty mesons have been employed. We have used inputs from lattice QCD to minimize the model dependence of the results. We obtain the value of the initial entropy density, which varies from 20 to 59/fm${}^3$ depending on the value of the velocity of sound that one uses for the analysis. Our investigation leads to a conservative value of the initial entropy density of $\sim$20/fm${}^3$ with a corresponding initial temperature of $\sim$210 MeV, which is well above the value of the transition temperature predicted by lattice QCD.

The recent high-resolution measurement of the electric dipole ($E1$) polarizability ${\alpha }_{\mathrm{D}}$ in ${}^{208}$Pb [A. Tamii et al., Phys. Rev. Lett. 107, 062502 (2011)] provides a unique constraint on the neutron-skin thickness of this nucleus. The neutron-skin thickness $r_{\mathrm{skin}}$ of ${}^{208}$Pb is a quantity of critical importance for our understanding of a variety of nuclear and astrophysical phenomena. To assess the model dependence of the correlation between ${\alpha }_{\mathrm{D}}$ and $r_{\mathrm{skin}}$, we carry out systematic calculations for ${}^{208}$Pb, ${}^{132}$Sn, and ${}^{48}$Ca based on the nuclear density functional theory using both nonrelativistic and relativistic energy density functionals. Our analysis indicates that whereas individual models exhibit a linear dependence between ${\alpha }_{\mathrm{D}}$ and $r_{\mathrm{skin}}$, this correlation is not universal when one combines predictions from a host of different models. By averaging over these model predictions, we provide estimates with associated systematic errors for $r_{\mathrm{skin}}$ and ${\alpha }_{\mathrm{D}}$ for the nuclei under consideration. We conclude that precise measurements of $r_{\mathrm{skin}}$ in both ${}^{48}$Ca and ${}^{208}$Pb—combined with the recent measurement of ${\alpha }_{\mathrm{D}}$—should significantly constrain the isovector sector of the nuclear energy density functional.

The neutron-rich praseodymium isotopes ${}^{151}$Pr and ${}^{153}$Pr have been studied by prompt $\gamma$-ray spectroscopy using ${}^{248}$Cm and ${}^{252}$Cf spontaneous-fission sources placed inside the EUROGAM-II and Gammasphere germanium arrays, respectively. Rotational bands based on $3/2^{-}$[541] states, with similar structures, have been assigned to these nuclei. These bands decay by intraband $E2$ transitions. Interband $E1$ transitions, reported in other works, were not observed. Delayed conversion-electron and $\gamma$-ray spectroscopy of an $A=151$ nucleus has been performed at the Lohengrin mass spectrometer. A previously reported 35.1-keV isomer of ${}^{151}$Pr has been determined to decay by an $E1$ transition, and its half-life of 50(8) $\mu$s has been measured. Calculations performed using a reflection-symmetric quasi-particle-rotor model successfully reproduce the energies of the excited states of these nuclei and their decay patterns. The spin of the isomer has been assigned to be (1/2${}^{+}$, 3/2${}^{+}$) from a comparison with the calculations. The long half-life of this isomer and the lack of intraband $E1$ transitions show an absence of strong octupole correlations in the observed states of ${}^{151,153}$Pr. This is explained in terms of increasing quadrupole deformation reducing the number of Nilsson orbitals close to the Fermi surface available to form octupole collectivity.