Analysis of fluctuations of hadron production properties in collisions of relativistic particles profits from use of measurable intensive quantities which are independent of system size variations. The first family of such quantities was proposed in 1992; another is introduced in this paper. Furthermore we present a proof of independence of volume fluctuations for quantities from both families within the framework of the grand canonical ensemble. These quantities are referred to as strongly intensive ones. Influence of conservation laws and resonance decays is also discussed.

We investigate all pure quantum-electrodynamics corrections to the $np\to 1s$, $n=2$–4 transition energies of pionic hydrogen larger than $1\mathrm{meV}$, which requires an accurate evaluation of all relevant contributions up to order ${\alpha }^5$. These values are needed to extract an accurate strong interaction shift from experiment. Many small effects, such as second-order and double vacuum polarization contribution, proton and pion self-energies, finite size and recoil effects are included with exact mass dependence. Our final value differs from previous calculations by up to $\approx$$11\mathrm{ppm}$ for the $1s$ state, while a recent experiment aims at a $4\mathrm{ppm}$ accuracy.

The production cross sections of four $N=127$ isotones (${}^{207}$Hg, ${}^{206}$Au, ${}^{205}$Pt, and ${}^{204}$Ir) have been measured using ($p$,$n$) charge-exchange reactions, induced in collisions of a ${}^{208}$Pb primary beam at 1 A GeV with a Be target. These data allow one to investigate the use of a reaction mechanism to extend the limits of the chart of nuclides toward the important $r$-process nuclei in the region of the third peak of elemental abundance distribution.

Given the short lifetime and small volume of the quark-gluon plasma (QGP) formed in heavy ion collisions, a possible critical endpoint (CEP) will be blurred in a region and the effects from criticality severely smoothened. Nevertheless, the nonmonotonic behavior of correlation functions near criticality for systems of different sizes, given by different centralities in heavy ion collisions, must obey finite-size scaling. We apply the predicting power of scaling plots to the search for the CEP of strong interactions using data from heavy ion collisions at RHIC. The results of our data analysis exclude a critical point below chemical potentials $\mu ~400$ MeV. Extrapolating the analysis, we speculate that criticality could appear slightly above $\mu ~500$ MeV. Using available data we extrapolate our scaling curves to predict the behavior of new data at lower center-of-mass energy, currently being investigated in the Beam Energy Scan program at RHIC. If heavy-ion collisions drop out of the QGP phase before the CEP is reached, finite-size scaling might be the only way to experimentally estimate its position in the phase diagram.

A superposition of multiple resonance states in neutrinoless double-electron capture in ${}^{156}\text{Dy}$ has been discovered. Penning-trap mass spectrometry has been used for atomic-mass-difference measurements and careful calculations of electron wave functions and double-hole binding energies have been performed to determine the resonance-enhancement factors. Transitions to four nuclear excited states in the daughter nuclide ${}^{156}\text{Gd}$ have been identified as resonantly enhanced, including one with a full resonant enhancement, within the uncertainty of 100 eV. This phenomenon is unique in that it can be used to probe the mechanisms of neutrinoless processes.

The interactions of an $E/A=70$-MeV ${}^9\mathrm{C}$ beam with a Be target was used to populate levels in Be, B, and C isotopes, which undergo decay into many-particle exit channels. The decay products were detected in the HiRA array and the level energies were identified from their invariant mass. Correlations between the decay products were examined to deduce the nature of the decays, specifically to what extent all the fragments were created in one prompt step or whether the disintegration proceeded in a sequential fashion through long-lived intermediate states. In the latter case, information on the spin of the level was also obtained. Of particular interest is the five-body decay of the ${}^8\mathrm{C}$ ground state, which was found to disintegrate in two steps of two-proton decay passing through the ${}^6\mathrm{Be}$${}_{g.s.}$ intermediate state. The isobaric analog of ${}^8\mathrm{C}$${}_{g.s.}$ in ${}^8\mathrm{B}$ was also found to undergo two-proton decay to the isobaric analog of ${}^6\mathrm{Be}$${}_{g.s.}$ in ${}^6\mathrm{Li}$. A 9.69-MeV state in ${}^{10}\mathrm{C}$ was found to undergo prompt four-body decay to the 2$p$ $+$ 2$\alpha$ exit channel. The two protons were found to have a strong enhancement in the diproton region and the relative energies of all four $p$-$\alpha$ pairs were consistent with the ${}^5\mathrm{Li}$${}_{g.s.}$ resonance.

We study the $N/Z$ and $N/A$ dependence of balance energy ($E_{\text{bal}}$) for isotopic series of Ca having $N/Z$ ($N/A$) varying from 1.0 to 2.0 (0.5 to 0.67). We show that the $N/Z$ ($N/A$) dependence of $E_{\text{bal}}$ is sensitive to symmetry energy and its density dependence at densities higher than saturation density and is insensitive toward the isospin dependence of nucleon-nucleon ($\mathit{nn}$) cross section and Coulomb repulsion. We also study the effect of momentum-dependent interactions (MDI) on the $N/Z$ ($N/A$) dependence of $E_{\text{bal}}$. We find that although MDI influences the $E_{\text{bal}}$ drastically, the $N/Z$ ($N/A$) dependence of $E_{\text{bal}}$ remains unchanged on inclusion of MDI.

We obtain a new set of parameters in a multiphase transport (AMPT) model that are able to describe both the charged particle multiplicity density and the elliptic flow measured in $\mathrm{Au}+\mathrm{Au}$ collisions at center-of-mass energy $\sqrt{s_{NN}}=200$ GeV at the Relativistic Heavy Ion Collider, although they still give somewhat softer transverse momentum spectra. We then use the model to predict the triangular flow due to fluctuations in the initial collision geometry and study its effect relative to those from other harmonic components of anisotropic flows on the dihadron azimuthal correlations in both central and midcentral collisions.

We have determined the transparency of the nuclear medium to kaons from $A(e,e{}^{\prime }{K}^{+})$ measurements on ${}^{12}\mathrm{C}$, ${}^{63}\mathrm{Cu}$, and ${}^{197}\mathrm{Au}$ targets. The measurements were performed at the Jefferson Laboratory and span a range in four-momentum-transfer squared $Q^2=1.1–3.0\hspace{0.5em}{\mathrm{GeV}}^2$. The nuclear transparency was defined as the ratio of measured kaon electroproduction cross sections with respect to deuterium (${\sigma }^A/{\sigma }^D$). We further extracted the atomic number ($A$) dependence of the transparency as parametrized by $T=(A/2){}^{\alpha -1}$ and, within a simple model assumption, the in-medium effective kaon-nucleon cross sections. The effective cross sections extracted from the electroproduction data were found to be smaller than the free cross sections determined from kaon-nucleon scattering experiments, and the parameter $\alpha$ was found to be significantly larger than those obtained from kaon-nucleus scattering. We have included similar comparisons between pion- and proton-nucleon effective cross sections as determined from electron-scattering experiments and pion-nucleus and proton-nucleus scattering data.

The $g$ factors of the first excited 2${}^{+}$ states in the ${}^{112,114,116,122,124}$Sn isotopes have been measured with high accuracy using the transient field technique in combination with Coulomb excitation in inverse kinematics. The experimental results are discussed in a qualitative way on the basis of empirical single-particle $g$ factors of the relevant proton and neutron orbitals and are compared to a number of different theoretical calculations. The results are found to be best described by shell-model calculations in an extended configuration space. Clear evidence for the contribution of neutron pair excitations from the 1$d_{3/2}$ to the 0$h_{11/2}$ orbital to the wave function of the 2${}_1^{+}$ state in ${}^{122,124}$Sn has been obtained.

We present results on dielectron production in ${}^{40}\mathrm{Ar}+\mathrm{KCl}$ collisions at 1.76$A$ GeV. For the first time $\omega$ mesons could be reconstructed in a heavy-ion reaction at a bombarding energy which is well below the production threshold in free nucleon-nucleon collisions. The $\omega$ multiplicity has been extracted and compared to the yields of other particles, in particular of the $\phi$ meson. At intermediate $e^{+}{e}^{-}$ invariant masses, we find a strong enhancement of the pair yield over a reference spectrum from elementary nucleon-nucleon reactions, suggesting the onset of nontrivial effects of the nuclear medium. Transverse-mass spectra and angular distributions have been reconstructed in three invariant mass bins. In the former unexpectedly large slopes are found for high-mass pairs. The latter, in particular the helicity-angle distributions, are largely consistent with expectations for a pair cocktail dominated at intermediate masses by $\Delta$ Dalitz decays.

Proton-activation reactions on natural and enriched palladium samples were investigated via the activation technique in the energy range of $E_p=2.75$–9 MeV, close to the upper end of the respective Gamow window of the $\gamma$ process. We have determined cross sections for ${}^{102}$Pd$(p,\gamma )$${}^{103}$Ag, ${}^{104}$Pd$(p,\gamma )$${}^{105}$Ag, and ${}^{105}$Pd$(p,n)$${}^{105}$Ag, as well as partial cross sections of ${}^{104}$Pd$(p,n)$${}^{104}$Ag${}^g$, ${}^{105}$Pd$(p,\gamma )$${}^{106}$Ag${}^m$, ${}^{106}$Pd$(p,n)$${}^{106}$Ag${}^m$, and ${}^{110}$Pd$(p,n)$${}^{110}$Ag${}^m$ with uncertainties between 3% and 15% for constraining theoretical Hauser-Feshbach rates and for direct use in $\gamma$-process calculations.

The half-life of the ground state of ${}^{229}\mathrm{Th}$ (${}^{229}\mathrm{Th}$${}^g$) has become an important factor in nuclear technology, for example, in the geological disposal of nuclear spent fuel. However, the values reported in two previous studies are not in agreement. This study reevaluates the half-life of ${}^{229}\mathrm{Th}$${}^g$ by using a simple and reliable method. The ${}^{232}\mathrm{U}$/${}^{233}\mathrm{U}$ activity ratio of a ${}^{232,233}\mathrm{U}$ sample was measured by high-resolution $\alpha$-particle spectrometry. Next, the ${}^{228}\mathrm{Th}$/${}^{229}\mathrm{Th}$${}^g$ activity ratio of the Th sample, which was grown from the ${}^{232,233}\mathrm{U}$ sample, was also measured. The half-life of ${}^{229}\mathrm{Th}$${}^g$ was calculated from these activity ratios, the growth time, and the half-lives of ${}^{232}\mathrm{U}$, ${}^{233}\mathrm{U}$, and ${}^{228}\mathrm{Th}$. From the results of these five measurements, the half-life of ${}^{229}\mathrm{Th}$${}^g$ is determined to be 7932 $\pm$ 55 yr at a confidence level of 2$\sigma$.

We have calculated the binding energy, root-mean-square radius, and quadrupole deformation parameter for the recently synthesized superheavy element $Z=117$, using the axially deformed relativistic mean-field (RMF) model. The calculation is extended to various isotopes of the $Z=117$ element, starting from $A=286$ till $A=310$. We predict almost spherical structures in the ground state for almost all the isotopes. A shape transition appears at about $A=292$ from a prolate to an oblate shape structure of the $Z=117$ nucleus in our mean-field approach. The most stable isotope (largest binding energy per nucleon) is found to be the ${}^{288}$117 nucleus. Also, the $Q_{\alpha }$ values and the half-life $T_{1/2}^{\alpha }$ for the $\alpha$-decay chains of ${}^{293}$117 and ${}^{294}$117 are calculated, supporting the magic numbers at $N=172$ and/or 184.

We compute the ground-state properties of finite systems of neutrons in an external harmonic trap, interacting via the Minnesota potential, using the “exact-exchange” form of orbital-dependent density functional theory. We compare our results with Hartree-Fock calculations and find very close agreement. Within the context of the interaction studied, we conclude that this simple orbital-dependent functional brings conventional nuclear density functional theory to the level of Hartree-Fock in an ab initio fashion. Our work is a first step toward higher order ab initio nuclear functionals based on realistic nucleon-nucleon interactions.

The synthesis of rare-earth neutron-deficient nuclei with large $Z/N$ ratio $\approx 0.88$ is studied within the framework of the standard statistical model. The fusion cross sections are calculated on the basis of the nuclear reaction video model. The deexcitation process is calculated with the help of the statistical code alice. It is found that the excitation functions can be predicted using a few exited experimental data by carefully choosing the input parameters in the statistical model. The results obtained show that a satisfactory description of the experimental evaporation cross sections requires a great reduction in the theoretical fission barriers.

The present work is dedicated to a careful investigation of the influence of the potential energy surface on the fission process. The time evolution of nuclei at high excitation energy and angular momentum is studied by means of three-dimensional Langevin calculations performed for two different parametrizations of the macroscopic potential: the Finite Range Liquid Drop Model (FRLDM) and the Lublin-Strasbourg Drop (LSD) prescription. Depending on the mass of the system, the topology of the potential throughout the deformation space of interest in fission is observed to noticeably differ within these two approaches, due to the treatment of curvature effects. When utilized in the dynamical calculation as the driving potential, the FRLDM and LSD models yield similar results in the heavy-mass region, whereas the predictions can be strongly dependent on the Potential Energy Surface (PES) for medium-mass nuclei. In particular, the mass, charge, and total kinetic energy distributions of the fission fragments are found to be narrower with the LSD prescription. The influence of critical model parameters on our findings is carefully investigated. The present study sheds light on the experimental conditions and signatures well suited for constraining the parametrization of the macroscopic potential. Its implication regarding the interpretation of available experimental data is briefly discussed.

The properties of open charm mesons, $D$, $\overline{D}$, $D_s$, and ${\overline{D}}_s$ in nuclear matter at finite temperature are studied within a self-consistent coupled-channel approach. The interaction of the low-lying pseudoscalar mesons with the ground-state baryons in the charm sector is derived from a $t$-channel vector-exchange model. The in-medium scattering amplitudes are obtained by solving the Lippmann-Schwinger equation at finite temperature including Pauli blocking effects, baryon dressing, as well as $D$, $\overline{D}$, $D_s$, and ${\overline{D}}_s$ self-energies taking their mutual influence into account. We find that the in-medium properties of the $D$ meson are affected by the $D_s$-meson self-energy through the intermediate $D_{s}Y$ loops coupled to $DN$ states. Similarly, dressing the $\overline{D}$ meson in the $\overline{D}Y$ loops has an influence over the properties of the ${\overline{D}}_s$ meson.

We have performed a calculation of the scattering amplitude for the three-body system $\overline{K}NN$ assuming $\overline{K}$ scattering against a $NN$ cluster using the fixed center approximation to the Faddeev equations. The $\overline{K}N$ amplitudes, which we take from chiral unitary dynamics, govern the reaction and we find a $\overline{K}NN$ amplitude that peaks around 40 MeV below the $\overline{K}NN$ threshold, with a width in ${\left|T\right|}^2$ of the order of 50 MeV for spin 0 and has another peak around 27 MeV with similar width for spin 1. The results are in line with those obtained using different methods but implementing chiral dynamics. The simplicity of the approach allows one to see the important ingredients responsible for the results. In particular, we show the effects from the reduction of the size of the $NN$ cluster due to the interaction with the $\overline{K}$ and those from the explicit consideration of the $\pi \Sigma N$ channel in the three-body equations.