The FRS-ESR facility at GSI provides unique conditions for precision measurements of large areas on the nuclear mass surface in a single experiment. Values for masses of 604 neutron-deficient nuclides ($30\le Z\le 92$) were obtained with a typical uncertainty of $30\mu \mathrm{u}$. The masses of 114 nuclides were determined for the first time. The odd-even staggering (OES) of nuclear masses was systematically investigated for isotopic chains between the proton shell closures at $Z=50$ and $Z=82$. The results were compared with predictions of modern nuclear models. The comparison revealed that the measured trend of OES is not reproduced by the theories fitted to masses only. The spectral pairing gaps extracted from models adjusted to both masses, and density related observables of nuclei agree better with the experimental data.

Ground-state proton radioactivity has been identified from ${}^{121}\mathrm{Pr}$. A transition with a proton energy of $E_p=882(10)\mathrm{keV}$ [$Q_p=900(10)\mathrm{keV}$] and half-life $t_{1/2}={10}_{-3}^{+6}\mathrm{ms}$ has been observed and is assigned to the decay of a highly prolate deformed $3/2^{+}$ or $3/2^{-}$ Nilsson state. The present result is found to be incompatible with a previously reported observation of ground-state proton radioactivity from ${}^{121}\mathrm{Pr}$, which would have represented the discovery of this phenomenon.

In-beam $\gamma$-ray spectroscopic measurements have been made on ${}_{102}{}^{253}\mathrm{No}$. A single rotational band was identified up to a probable spin of $39/2\hslash$, which is assigned to the $7/2^{+}[624]$ Nilsson configuration. The bandhead energy and the moment of inertia provide discriminating tests of contemporary models of the heaviest nuclei. Novel methods were required to interprete the sparse data set associated with cross sections of around 50 nb. These methods included comparisons of experimental and simulated spectra, as well as testing for evidence of a rotational band in the $\gamma \gamma$ matrix.

The momentum and isospin dependence of the in-medium nucleon mass are studied. Two definitions of the effective mass, i.e., the Dirac mass $m_D^{*}$ and the nonrelativistic mass $m_{NR}^{*}$ which parametrizes the energy spectrum, are compared. Both masses are determined from relativistic Dirac-Brueckner-Hartree-Fock calculations. The nonrelativistic mass shows a distinct peak around the Fermi momentum. The proton-neutron mass splitting in isospin asymmetric matter is $m_{D,n}^{*}<m_{D,p}^{*}$ and opposite for the nonrelativistic mass, i.e., $m_{NR,n}^{*}>m_{NR,p}^{*}$, which is consistent with nonrelativistic approaches.

We report on the first determination of the absolute $B(E2;0_1^{+}\to 2_1^{+})$ excitation strength in the $N=Z$ nucleus ${}^{72}\mathrm{Kr}$. ${}^{72}\mathrm{Kr}$ is the heaviest $N=Z$ nucleus for which this quantity has been measured and provides a benchmark in a region of the nuclear chart dominated by rapidly changing deformations and shapes mediated by the interplay of strongly oblate and prolate-driving orbitals. The deduced quadrupole deformation strength is in agreement with a variety of self-consistent models that predict an oblate shape for the ground state of ${}^{72}\mathrm{Kr}$. Large-scale shell-model Monte Carlo calculations reproduce the experimental $B(E2)$ value and link the result to the occupation of the deformation-driving $g_{9/2}$ orbit.

It is argued that in heavy ion collisions at the CERN Large Hadron Collider (LHC) there could be a sizable production of baryons containing two or three heavy quarks from statistical coalescence. This production mechanism is peculiar of quark gluon plasma, and the predicted rates, in heavy ion collisions at LHC energies, exceed those from a purely hadronic scenario, particularly for ${\Xi }_{bc}$ and ${\Omega }_{ccc}$. Thus, in addition to the interest in the discovery of these new states, enhanced ratios of these baryons over singly heavy flavored hadrons, like $B$ or $D$, in heavy ion collisions with respect to $pp$ at the same energy, would be a clear indication of kinetic equilibration of heavy quarks in the quark gluon plasma.

We have observed direct one-proton decay of the $({21}^{+})$ isomer in the $N=Z$ nuclide ${}^{94}\mathrm{Ag}$ into high-spin states in ${}^{93}\mathrm{Pd}$ by detecting protons in coincidence with $\gamma \mathrm{\text{−}}\gamma$ correlations and applying $\gamma$ gates based on known ${}^{93}\mathrm{Pd}$ levels. Two decay branches have been identified, with proton energies of 0.79(3) and 1.01(3) MeV and branching ratios of 1.9(5)% and 2.2(4)%, respectively. The corresponding partial half-life values are 21(6) and 18(4) s. The $Q$ value of the direct proton decay of the $({21}^{+})$ isomer was found to be 5.78(3) MeV. The very small reduced widths of the observed proton decays might reflect dominating collective configurations in the $({21}^{+})$ isomer, and the fine structure of the proton spectrum might indicate a strong deformation of this state.

Azimuthal distributions of ${\pi }^{+}$, $K^{+}$, and $K^{-}$ mesons have been measured in $\mathrm{Au}+\mathrm{Au}$ reactions at $1.5A\mathrm{GeV}$ and $\mathrm{Ni}+\mathrm{Ni}$ reactions at $1.93A\mathrm{GeV}$. In semicentral collisions at midrapidity, ${\pi }^{+}$ and $K^{+}$ mesons are emitted preferentially perpendicular to the reaction plane in both collision systems. In contrast for $K^{-}$ mesons in $\mathrm{Ni}+\mathrm{Ni}$ reactions, an in-plane elliptic flow was observed for the first time at these incident energies.

New measurements are presented for charged hadron azimuthal correlations at midrapidity in $\mathrm{Au}+\mathrm{Au}$ collisions at $\sqrt{s_{NN}}=62.4$ and 200 GeV. They are compared to earlier measurements obtained at $\sqrt{s_{NN}}=130\mathrm{GeV}$ and in $\mathrm{Pb}+\mathrm{Pb}$ collisions at $\sqrt{s_{NN}}=17.2\mathrm{GeV}$. Sizeable anisotropies are observed with centrality and transverse momentum ($p_T$) dependence characteristic of elliptic flow ($v_2$). For a broad range of centralities, the observed magnitudes and trends of the differential anisotropy, $v_2(p_T)$, change very little over the collision energy range $\sqrt{s_{NN}}=62–200\mathrm{GeV}$, indicating saturation of the excitation function for $v_2$ at these energies. Such a saturation may be indicative of the dominance of a very soft equation of state for $\sqrt{s_{NN}}\sim 60–200\mathrm{GeV}$.

The first measurement of direct photons in $\mathrm{Au}+\mathrm{Au}$ collisions at $\sqrt{s_{NN}}=200\mathrm{GeV}$ is presented. The direct photon signal is extracted as a function of the $\mathrm{Au}+\mathrm{Au}$ collision centrality and compared to next-to-leading order perturbative quantum chromodynamics calculations. The direct photon yield is shown to scale with the number of nucleon-nucleon collisions for all centralities.

We discuss the possibility of producing the bound states of the ${\eta }^{\prime }(958)$ meson in nuclei theoretically. We calculate the formation cross sections of the ${\eta }^{\prime }$ bound states with the Green function method for the $(\gamma ,p)$ reaction and discuss the experimental feasibility at photon facilities such as SPring-8. We conclude that we can expect to observe resonance peaks in $(\gamma ,p)$ spectra for the formation of ${\eta }^{\prime }$ bound states and we can deduce new information on ${\eta }^{\prime }$ properties at finite density. These observations are believed to be essential to know the possible mass shift of ${\eta }^{\prime }$ and deduce new information on the effective restoration of the chiral $U_A(1)$ anomaly in the nuclear medium.

The nucleus ${}^{54}\mathrm{Zn}$ has been observed for the first time in an experiment at the SISSI/LISE3 facility of GANIL in the quasifragmentation of a ${}^{58}\mathrm{Ni}$ beam at $74.5\mathrm{MeV}/\mathrm{\text{nucleon}}$ in a ${}^{\mathrm{nat}}\mathrm{Ni}$ target. The fragments were analyzed by means of the ALPHA-LISE3 separator and implanted in a silicon-strip detector where correlations in space and time between implantation and subsequent decay events allowed us to generate almost background free decay spectra for about 25 different nuclei at the same time. Eight ${}^{54}\mathrm{Zn}$ implantation events were observed. From the correlated decay events, the half-life of ${}^{54}\mathrm{Zn}$ is determined to be ${3.2}_{-0.8}^{+1.8}\mathrm{ms}$. Seven of the eight implantations are followed by two-proton emission with a decay energy of 1.48(2) MeV. The decay energy and the partial half-life are compared to model predictions and allow for a test of these two-proton decay models.

We present a comprehensive mean-field calculation of the Schiff moment of the nucleus ${}^{225}\mathrm{Ra}$, the quantity that determines the static electric-dipole moment of the corresponding atom if time-reversal ($T$) invariance is violated in the nucleus. The calculation breaks all possible intrinsic symmetries of the nuclear mean field and includes, in particular, both exchange and direct terms from the full finite-range $T$-violating nucleon-nucleon interaction, and the effects of short-range correlations. The resulting Schiff moment, which depends on three unknown $T$-violating pion-nucleon coupling constants, is much larger than in ${}^{199}\mathrm{Hg}$, the isotope with the best current experimental limit on its atomic electric-dipole moment.

We have searched for a deeply bound kaonic state by using the FINUDA spectrometer installed at the $e^{+}{e}^{-}$ collider $\mathrm{DA}\Phi \mathrm{NE}$. Almost monochromatic $K^{-}$’s produced through the decay of $\varphi (1020)$ mesons are used to observe $K^{-}$ absorption reactions stopped on very thin nuclear targets. Taking this unique advantage, we have succeeded to detect a kaon-bound state $K^{-}pp$ through its two-body decay into a $\Lambda$ hyperon and a proton. The binding energy and the decay width are determined from the invariant-mass distribution as ${115}_{-5}^{+6}(\mathrm{stat}{)}_{-4}^{+3}(\mathrm{syst})\mathrm{MeV}$ and ${67}_{-11}^{+14}(\mathrm{stat}{)}_{-3}^{+2}(\mathrm{syst})\mathrm{MeV}$, respectively.

We report converged results for the ground and excited states and matter density of ${}^{16}\mathrm{O}$ using realistic two-body nucleon-nucleon interactions and coupled-cluster methods and algorithms developed in quantum chemistry. Most of the binding is obtained with the coupled-cluster singles and doubles approach. Additional binding due to three-body clusters (triples) is minimal. The coupled-cluster method with singles and doubles provides a good description of the matter density, charge radius, charge form factor, and excited states of a one-particle, one-hole nature, but it cannot describe the first-excited $0^{+}$ state. Incorporation of triples has no effect on the latter finding.

The total scattering cross sections for slow neutrons with energies $E$ in the range 300 neV to 3 meV for gaseous and liquid ortho-${}^2\mathrm{H}_2$ have been measured. The cross sections for ${}^2\mathrm{H}_2$ gas are found to be in excellent agreement with both the Hamermesh and Schwinger and the Young and Koppel models. For liquid ${}^2\mathrm{H}_2$, we confirm the existing experimental data in the cold neutron range and the discrepancy with the gas models. We find a clear $1/\sqrt{E^{\prime }}$ dependence at low energies for both states. A simple explanation for the liquid ${}^2\mathrm{H}_2$ cross section is offered.

Higher-order QED effects play an important role in precision measurements of nucleon elastic form factors in electron scattering. Here we introduce a two-photon-exchange QED correction to the parity-violating polarization asymmetry of elastic electron-proton scattering. We calculate this correction in the parton model using the formalism of generalized parton distributions, and demonstrate that it can reach several percent in certain kinematics, becoming comparable in size with existing experimental measurements of strange-quark effects in the proton neutral weak current.

The DEAR (DA$\Phi$NE exotic atom research) experiment measured the energy of x rays emitted in the transitions to the ground state of kaonic hydrogen. The measured values for the shift $ϵ$ and the width $\Gamma$ of the 1$s$ state due to the $K^{-}p$ strong interaction are ${ϵ}_{1s}=-193\pm 37$ (stat) $\pm 6$ (syst) eV and ${\Gamma }_{1s}=249\pm 111$ (stat) $\pm 30$ (syst) eV, the most precise values yet obtained. The pattern of the kaonic hydrogen $K$-series lines, $K_{\alpha }$, $K_{\beta }$, and $K_{\gamma }$, was disentangled for the first time.

We describe ab initio calculations of doubly strange, $S=-2$, $s$-shell hypernuclei (${}_{\Lambda \Lambda }{}^4\mathrm{H}$, ${}_{\Lambda \Lambda }{}^5\mathrm{H}$, ${}_{\Lambda \Lambda }{}^5\mathrm{He}$, and ${}_{\Lambda \Lambda }{}^6\mathrm{He}$) as a first attempt to explore the few-body problem of the full-coupled channel scheme for these systems. The wave function includes $\Lambda \Lambda$, $\Lambda \Sigma$, $N\Xi$, and $\Sigma \Sigma$ channels. Minnesota $NN$, $\mathrm{D}{2}^{\prime }$ $YN$, and simulated $YY$ potentials based on the Nijmegen hard-core model are used. Bound-state solutions of these systems are obtained. We find that a set of phenomenological $B_8{B}_8$ interactions among the octet baryons in $S=0,-1$, and $-2$ sectors, which is consistent with all of the available experimental binding energies of $S=0,-1$, and $-2$ $s$-shell (hyper)nuclei, can predict a particle stable bound state of ${}_{\Lambda \Lambda }{}^4\mathrm{H}$. For ${}_{\Lambda \Lambda }{}^5\mathrm{H}$ and ${}_{\Lambda \Lambda }{}^5\mathrm{He}$, $\Lambda N$-$\Sigma N$ and $\Xi N$-$\Lambda \Sigma$ potentials significantly affect the net $\Lambda \Lambda$-$N\Xi$ coupling, and a large $\Xi$ probability is obtained even for a weaker $\Lambda \Lambda$-$N\Xi$ potential.

The effects of the finite size of a liquid drop undergoing a phase transition are described in terms of the complement, the largest (but mesoscopic) drop representing the liquid in equilibrium with the vapor. Vapor cluster concentrations, pressure, and density from fixed mean density lattice gas (Ising) calculations are explained in terms of the complement generalization of Fisher’s model. Accounting for this finite size effect is important for extracting the infinite nuclear matter phase diagram from experimental data.