Event-by-event fluctuations of the kaon to pion number ratio in nucleus-nucleus collisions are studied within the statistical hadron-resonance gas model (SM) for different statistical ensembles and in the hadron-string-dynamics (HSD) transport approach. We find that the HSD model can qualitatively reproduce the measured excitation function for the $K/\pi$ ratio fluctuations in central $\mathrm{Au}+\mathrm{Au}$ (or $\mathrm{Pb}+\mathrm{Pb}$) collisions from low Super Proton Synchrotron up to top Relativistic Heavy Ion Collider energies. Substantial differences in the HSD and SM results are found for the fluctuations and correlations of the kaon and pion numbers. These predictions impose a challenge for future experiments.

We calculate the in-medium $D$ and $\overline{D}$ meson masses in isospin-asymmetric nuclear matter in an effective chiral model. The $D$ and $\overline{D}$ mass modifications arising from their interactions with the nucleons and the scalar mesons in the effective hadronic model are seen to be appreciable at high densities and have a strong isospin dependence. These mass modifications can open the channels of the decay of the charmonium states $({\Psi }^{\text{'}},{\chi }_c,J/\Psi )$ to $D\overline{D}$ pairs in dense hadronic matter. The isospin asymmetry in the doublet $D=(D^0,D^{+})$ is seen to be particularly appreciable at high densities and should show in observables such as their production and flow in asymmetric heavy-ion collisions in the compressed baryonic matter experiments in the future facility of FAIR, GSI. The results of the present work are compared to calculations of the $D(\overline{D}$) in-medium masses in the literature using the QCD sum rule approach, quark meson coupling model, and coupled channel approach as well as to those from studies of quarkonium dissociation using heavy-quark potentials from lattice QCD at finite temperatures.

The dynamical coupled-channels approach developed at the Excited Baryon Analysis Center is extended to include the $\omega N$ channel to study π- and ω-meson production induced by scattering pions and photons from the proton. Six intermediate channels, including $\pi N$, $\eta N$, $\pi \Delta$, $\sigma N$, $\rho N$, and $\omega N$, are employed to describe unpolarized and polarized data. Bare parameters in an effective hadronic Lagrangian are determined in a fit to the data for $\pi N\to \pi N$, $\gamma N\to \pi N$, ${\pi }^{-}p\to \omega n$, and $\gamma p\to \omega p$ reactions at center-of-mass energies from threshold to $W<2.0$ GeV. The $T$ matrix determined in these fits is used to calculate the photon beam asymmetry for ω-meson production and the $\omega N\to \omega N$ total cross section and $\omega N$-scattering lengths. The calculated beam asymmetry is in good agreement with the observed in the range of energies near threshold to $W\lesssim 2.0$ GeV.

Recently, charge radii and ground-state electromagnetic moments of Li and Be isotopes were measured precisely. We have performed large-scale ab initio no-core shell model calculations for these isotopes using high-precision nucleon-nucleon potentials. The isotopic trends of our computed charge radii and quadrupole and magnetic-dipole moments are in good agreement with experimental results with the exception of the ${}^{11}\mathrm{Li}$ charge radius. The magnetic moments are in particular well described, whereas the absolute magnitudes of the quadrupole moments are about $10\%$ too small. The small magnitude of the ${}^6\mathrm{Li}$ quadrupole moment is reproduced, and with the CD-Bonn $NN$ potential, also its correct sign.

A systematic search for the nuclei in which the observation of discrete hyperdeformed (HD) bands may be feasible with existing detector facilities has been performed in the Cd isotopes within the framework of cranked relativistic mean-field theory. It was found that the ${}^{96}\mathrm{Cd}$ nucleus is a doubly magic HD nucleus owing to large proton $Z=48$ and neutron $N=48$ HD shell gaps. The best candidate for an experimental search of discrete HD bands is the ${}^{107}\mathrm{Cd}$ nucleus characterized by the large energy gap between the yrast and excited HD bands, the size of which is only 15% smaller than the one in the doubly magic HD ${}^{96}\mathrm{Cd}$ nucleus.

Recoil-isomer tagging has been used to characterize the states built upon an $I^{\pi }=8^{+}$ isomer in ${}^{142}\mathrm{Tb}$. High-spin states of the neutron-deficient nucleus ${}^{142}\mathrm{Tb}$ were populated using an ${}^{54}\mathrm{Fe}$ beam, accelerated onto a ${}^{92}\mathrm{Mo}$ target of thickness $~500\hspace{0.5em}\mu \mathrm{g}/{\mathrm{cm}}^2$ at energies of 245, 252, and 265 MeV using the K130 cyclotron at the University of Jyväskylä, Finland. Use of the JUROGAM target-position Ge-detector array coupled with the GREAT focal-plane spectrometer at the RITU gas-filled recoil separator has significantly increased the efficiency of the isomer-tagging technique. The rotational band built upon the $I^{\pi }=8^{+}$ isomeric state was established with isomer-tagged $\gamma \text{−}\gamma$ coincidence data and angular distributions were measured for some of the more intensely populated states. Two previously unobserved bands that bypass the isomer were also established. The new data have been interpreted within the framework of the cranked-shell model. The data show good agreement with the calculated triaxial nuclear shape with $\gamma =-{30}^{°}$ for the ${}^{142m2}\mathrm{Tb}$ isomeric state. The $B(M1)/B(E2)$ branching ratios, nuclear alignment, signature splitting, and reduced transition probability, $B(E1)$, of the isomeric state have been systematically compared with those of the neighboring nuclei. These comparisons give further evidence for the $\pi h_{11/2}\otimes \nu h_{11/2}$ configuration of the isomer.

Mass parameters for the relative and neck motions in fusion reactions of symmetric systems ${}^{90}\mathrm{Zr}+{}^{90}\mathrm{Zr}$, ${}^{110}\mathrm{Pd}+{}^{110}\mathrm{Pd}$, and ${}^{138}\mathrm{Ba}+{}^{138}\mathrm{Ba}$ are studied by means of a microscopic transport model. The shape of the nuclear system is determined by an equidensity surface obtained from the density distribution of the system. The relative and neck motions are then studied and the mass parameters for these two motions are deduced. The mass parameter for the relative motion is around the reduced mass when the reaction partners are at the separated configuration and increases with a decrease of the distance between two reaction partners after the touching configuration. The mass parameter for the neck motion first decreases slightly up to the touching configuration and then increases with the neck width, and its magnitude is from less than a tenth to several times more than the total mass of the system. The mass parameters obtained from the microscopic transport model are larger than the ones obtained from the hydrodynamic model and smaller than those obtained from the linear response function theory. The mass parameters for both motions depend on the reaction systems, but the one for the relative motion depends on the incompressibility of the EoS more obviously than that for neck motion.

A global optical model potential (GDP08) for ${}^3\mathrm{He}$ projectiles has been obtained by simultaneously fitting the elastic scattering data of ${}^3\mathrm{He}$ from targets of $40⩽A_T⩽209$ at incident energies of $30⩽E_{\mathrm{inc}}⩽217$ MeV. Uncertainties and correlation coefficients between the global potential parameters were obtained by using the bootstrap statistical method. GDP08 was found to satisfactorily account for the elastic scattering of ${}^3\mathrm{H}$ as well, which makes it a global optical potential for the $A=3$ nuclei. Optical model calculations using the GDP08 global potential are compared with the experimental angular distributions of differential cross sections for ${}^3\mathrm{He}$-nucleus and ${}^3\mathrm{H}$-nucleus scattering from different targets of $6⩽A_T⩽232$ at incident energies of $4⩽E_{\mathrm{inc}}⩽450$ MeV. The optical potential for the doubly-magic nucleus ${}^{40}\mathrm{Ca}$, the low-energy correction to the real potential for nuclei with $58\lesssim A_T\lesssim 120$ at $E_{\mathrm{inc}}<30$ MeV, the comparison with double-folding model calculations and the CH89 potential, and the spin-orbit potential parameters are discussed.

Reactions that involve the fast removal (knockout) of one and two neutrons from the neutron-rich carbon isotopes, ${}^{15-19}\mathrm{C}$, by light nuclear targets are studied within an eikonal reaction model. Shell model calculations are used to describe the excitation energy spectra and the structures of the carbon isotopes. The calculated one-neutron knockout cross sections from the ${}^A\mathrm{C}$ isotopes, to particle-bound configurations of the ${}^{A-1}\mathrm{C}$ residues, are in agreement with the available experimental data. The two-neutron removal cross sections, producing ${}^{A-2}\mathrm{C}$ residues, receive contributions from both the direct, single-step two-neutron knockout and the indirect mechanism, involving single-neutron removal strength to neutron-unbound excited states in the ${}^{A-1}\mathrm{C}$ system followed by neutron emission. The latter two-step reaction mechanism is shown to be dominant. The empirical odd-even staggering of the single-neutron separation energies along the carbon isotopic chain is reflected in the two-neutron removal data. This staggering and the magnitudes of the two-neutron removal cross sections are reproduced qualitatively by the theoretical calculations.

We present measurements of net charge fluctuations in $\mathrm{Au}+\mathrm{Au}$ collisions at $\sqrt{s_{\mathit{NN}}}=19.6$, $62.4$, $130$, and $200$ GeV, $\mathrm{Cu}+\mathrm{Cu}$ collisions at $\sqrt{s_{\mathit{NN}}}=62.4$ and $200$ GeV, and $p+p$ collisions at $\sqrt{s}=200$ GeV using the dynamical net charge fluctuations measure ${\nu }_{+-,\mathrm{dyn}}$. We observe that the dynamical fluctuations are nonzero at all energies and exhibit a modest dependence on beam energy. A weak system size dependence is also observed. We examine the collision centrality dependence of the net charge fluctuations and find that dynamical net charge fluctuations violate $1/N_{\mathrm{ch}}$ scaling but display approximate $1/N_{\mathrm{part}}$ scaling. We also study the azimuthal and rapidity dependence of the net charge correlation strength and observe strong dependence on the azimuthal angular range and pseudorapidity widths integrated to measure the correlation.

The new reaction ${}^{208}\mathrm{Pb}({}^{59}\mathrm{Co},n){}^{266}\mathrm{Mt}$ was studied using the Berkeley Gas-filled Separator at the Lawrence Berkeley National Laboratory 88-Inch Cyclotron. A cross section of ${7.7}_{-3.3}^{+5.2}$ pb was measured at a compound nucleus excitation energy of 14.9 MeV. The measured decay properties of ${}^{266}\mathrm{Mt}$ and its daughters correspond well with existing data. We compare this experimental result to transactinide compound nucleus formation model predictions, and the previously studied ${}^{209}\mathrm{Bi}({}^{58}\mathrm{Fe},n){}^{266}\mathrm{Mt}$ reaction.

We use a new method to search systematic trends in total fusion reactions of weakly bound nuclei at near-barrier energies. In a recent work, this method was employed to investigate these reactions in the case of heavy targets. Here, we extend this study to the light targets. Comparing fusion data with a dimensionless fusion excitation function, used as a benchmark, one can identify enhancement or suppression effects in fusion data. Through a proper renormalization of the data, it is possible to disentangle static and dynamic effects arising from the low dissociation energy of the projectile. Applying this method to the available data in the literature, we conclude that there is no appreciable suppression of enhancement in the total fusion data of light weakly bound systems. We point out that some unexpected deviations from this benchmark may possibly indicate problems with the data.

The correlated two-meson exchange contribution between a kaon and a nucleon has been investigated by a chiral unitary method. A strong short-ranged repulsion in the correlated two-meson exchange potential has been found. The calculated scalar potential with Breit frame kinematics is consistent with the positive $G$-parity part of the Jülich scalar potential in which a repulsive ${\sigma }_0$ exchange contributions is assumed to reproduce the scattering data.

We report the properties of the prompt dipole radiation, produced via a collective bremsstrahlung mechanism, in fusion reactions with exotic beams. We show that the $\gamma$ yield is sensitive to the density dependence of the symmetry energy below/around saturation. Moreover, we find that the angular distribution of the emitted photons from such fast collective mode can represent a sensitive probe of its excitation mechanism and of fusion dynamics in the entrance channel.

We present a pedagogical study of the commonly employed speed-plot (SP) and time-delay (TD) methods for extracting the resonance parameters from the data of two-particle coupled-channels reactions. Within several exactly solvable models, it is found that these two methods find poles on different Riemann sheets and are not always valid. We then develop an analytic continuation method for extracting nucleon resonances within a dynamical coupled-channel formulation of $\pi N$ and $\gamma N$ reactions. The main focus of this paper is on resolving the complications from the coupling with the unstable $\pi \Delta$, $\rho N$, and $\sigma N$ channels, which decay into $\pi \pi N$ states. By using the results from the considered exactly solvable models, explicit numerical procedures are presented and verified. As a first application of the developed analytic continuation method, we present the nucleon resonances in some partial waves extracted within a recently developed coupled-channels model of $\pi N$ reactions. The results from this realistic $\pi N$ model, which includes $\pi N$, $\eta N$, $\pi \Delta$, $\rho N$, and $\sigma N$ channels, also show that the simple pole parametrization of the resonant propagator using the poles extracted from SP and TD methods works poorly.

As a step toward performing a complete coupled-channels analysis of the world data of $\pi N,{\gamma }^{*}N\to \pi N,\eta N,\pi \pi N$ reactions, the $\pi N\to \pi \pi N$ reactions are investigated starting with the dynamical coupled-channels model developed in Phys. Rev. C 76, 065201 (2007). The channels included are $\pi N,\eta N$, and $\pi \pi N$ which has $\pi \Delta ,\rho N$, and $\sigma N$ resonant components. The nonresonant amplitudes are generated from solving a set of coupled-channels equations with the meson-baryon potentials defined by effective Lagrangians. The resonant amplitudes are generated from 16 bare excited nucleon $(N^{*})$ states that are dressed by the nonresonant interactions as constrained by the unitarity condition. The data of total cross sections and $\pi N$ and $\pi \pi$ invariant mass distributions of ${\pi }^{+}p\to {\pi }^{+}{\pi }^{+}n,{\pi }^{+}{\pi }^{0}p$ and ${\pi }^{-}p\to {\pi }^{+}{\pi }^{-}n,{\pi }^{-}{\pi }^{0}p,{\pi }^0{\pi }^{0}n$ reactions from threshold to the invariant mass $W=2$ GeV can be described to a very large extent. We show the importance of the coupled-channels effects and the strong interference among the contributions from the $\pi \Delta ,\sigma N$, and $\rho N$ channels. The large interference between the resonant and nonresonant amplitudes is also demonstrated. Possible future developments are discussed.

The measurement of nuclear generalized parton distributions (GPDs) will represent a valuable tool to understanding the structure of bound nucleons in the nuclear medium, as well as the role of non-nucleonic degrees of freedom in the phenomenology of hard scattering off nuclei. By using a realistic microscopic approach for the evaluation of GPDs of ${}^3\mathrm{He}$, it will be shown that conventional nuclear effects, such as isospin and binding ones, or the uncertainty related to the use of a given nucleon-nucleon potential, are rather bigger than in the forward case. These findings suggest that unless great attention is paid to not inferring the properties of nuclear GPDs from those of nuclear parton distributions, the conventional nuclear effects can be easily mistaken for exotic ones. It is stressed therefore that ${}^3\mathrm{He}$, for which the best realistic calculations are possible, represents a unique target for discriminating between conventional and exotic effects. The complementary information which could be obtained by using a ${}^3\mathrm{H}$ target is also addressed.

The calculations of three-body direct nuclear reactions with nonlocal optical potentials are performed for the first time using the framework of Faddeev-type scattering equations. An important nonlocality effect is found for transfer reactions such as $d+{}^{16}\mathrm{O}\to p+{}^{17}\mathrm{O}$, often improving the description of the experimental data.

The level densities and $\gamma$-ray strength functions of ${}^{205-208}\mathrm{Pb}$ have been measured with the Oslo method, using the $({}^3\mathrm{He},{}^3\mathrm{He}{}^{\text{'}}\gamma )$ and $({}^3\mathrm{He},\alpha \gamma )$ reactions on the target nuclei ${}^{206}\mathrm{Pb}$ and ${}^{208}\mathrm{Pb}$. The extracted level densities are consistent with known discrete levels at low excitation energies. The entropies and temperatures in the microcanonical ensemble have been deduced from the experimental level density. An average entropy difference of $\Delta S~0.9k_B$ has been observed between ${}^{205}\mathrm{Pb}$ and ${}^{206}\mathrm{Pb}$. The $\gamma$-ray strength functions in ${}^{205-208}\mathrm{Pb}$ have been extracted and compared with two models; however, none of them describe the data adequately. Intermediate structures have been observed in the $\gamma$-ray strength functions for $\gamma$-ray energies below neutron threshold in all the analyzed Pb nuclei. These structures become less pronounced while moving from the doubly magic nucleus ${}^{208}\mathrm{Pb}$ to ${}^{205}\mathrm{Pb}$.

The assisted tunneling of a wave packet between square one-dimensional barriers is treated analytically. The survival probability is calculated exactly for a potential mimicking a constant electric field with arbitrary time dependence. The pole spectrum of the properly normalized unperturbed wave functions determines the decay time. The tunneling probability is enhanced by the perturbation. The results are exemplified for a simplified model of nuclear $\alpha$ decay.