The relationship between the nucleon density at large radii and the value of the rms radius is investigated in the framework of Skyrme Hartree-Fock and relativistic mean-field models. From a comparison to the charge density we constrain the models in terms of the nuclear matter incompressibility and effective mass properties required to reproduce the density shape. The results are used to extract the rms neutron radius for ${}^{208}\mathrm{Pb}$ from antiprotonic atom data. The result for the difference between the neutron and proton rms radii, the so-called neutron-skin thickness, is $S=0.20(\pm 0.04)(\pm 0.05)$ fm, where $\pm 0.04$ fm is experimental error from the antiprotonic line width, and $\pm 0.05$ fm is the theoretical error suggested from the comparison of the models with the experimental charge density.

The $g(2_1^{+})$ values in the even Te isotopes between ${}^{122}\mathrm{Te}$ and ${}^{130}\mathrm{Te}$ have been measured simultaneously, relative to each other, by the transient-field technique. In addition, $g$ factors were also measured for the $3/2{}_2^{+}$ and $5/2{}_1^{+}$ levels in ${}^{125}\mathrm{Te}$.

In the light of new $g$ factor results for the stable isotopes between ${}^{122}\mathrm{Te}$ and ${}^{130}\mathrm{Te}$, the calibration and modeling of the recoil-in-vacuum (RIV) interaction for Te ions is reexamined, and the recent radioactive-beam $g$ factor measurement on ${}^{132}\mathrm{Te}$ by the RIV technique is reevaluated. The implications for further RIV $g$-factor measurements in the ${}^{132}\mathrm{Sn}$ region are discussed.

Electromagnetic transitions in ${}^{22}\mathrm{F}$ were investigated using the ${}^9\mathrm{Be}$(${}^{14}\mathrm{C}$, $p$) reaction at $E_{\mathrm{lab}}=22$ MeV. Proton-γ and proton-γ-γ coincidences were measured using a segmented $E$-ΔE Si telescope and the Florida State University γ detector array. γ-ray energies, intensities, and branching ratios were measured, and mean lifetimes were inferred using the Doppler-shift attenuation method. Several new states and many new γ-decay branches were observed. The results are compared with $\mathit{sd}$ shell model calculations using the USD, USDA, and USDB interactions. The excitation energies of the states below 2 MeV agree slightly better with the calculations using the USD interaction, while the levels between 2 and 4 MeV agree somewhat better with those using the newer USDA and USDB interactions.

Collisions of ${}^{112}\mathrm{Sn}$ and ${}^{124}\mathrm{Sn}$ nuclei, which differ in their isospin asymmetry, provide information about the rate of isospin diffusion and equilibration. Although several different probes can provide accurate diffusion measurements, the ratios of the mirror nuclei may be the simplest and most promising one. Ratios of the mass seven mirror nuclei yields are analyzed to show the rapidity, transverse momentum, and impact parameter dependence of isospin diffusion.

The longitudinal momentum distribution ($P_{//}$) of fragments after one-proton removal from ${}^{23}\mathrm{Al}$ and reaction cross sections (${\sigma }_R$) for ${}^{23,24}\mathrm{Al}$ on a carbon target at $74A$ MeV have been measured. The ${}^{23,24}\mathrm{Al}$ ions were produced through projectile fragmentation of $135A$ MeV ${}^{28}\mathrm{Si}$ primary beam using the RIPS fragment separator at RIKEN. $P_{//}$ is measured by a direct time-of-flight (TOF) technique, while ${\sigma }_R$ is determined using a transmission method. An enhancement in ${\sigma }_R$ is observed for ${}^{23}\mathrm{Al}$ compared with ${}^{24}\mathrm{Al}$. The $P_{//}$ for ${}^{22}\mathrm{Mg}$ fragments from ${}^{23}\mathrm{Al}$ breakup has been obtained for the first time. FWHM of the distributions has been determined to be 232 ± 28 MeV/$c$. The experimental data are discussed by using the Few-Body Glauber model. Analysis of $P_{//}$ demonstrates a dominant $d$-wave configuration for the valence proton in ground state of ${}^{23}\mathrm{Al}$, indicating that ${}^{23}\mathrm{Al}$ is not a proton halo nucleus.

Three-body resonances in the $\overline{K}\mathit{NN}$ system have been studied within a framework of the $\overline{K}\mathit{NN}$-$\pi YN$ coupled-channel Faddeev equation. By solving the three-body equation, the energy dependence of the resonant $\overline{K}N$ amplitude is fully taken into account. The $S$-matrix pole has been investigated from the eigenvalue of the kernel with the analytic continuation of the scattering amplitude on the unphysical Riemann sheet. The $\overline{K}N$ interaction is constructed from the leading order term of the chiral Lagrangian using relativistic kinematics. The $\Lambda (1405)$ resonance is dynamically generated in this model, where the $\overline{K}N$ interaction parameters are fitted to the data of scattering length. As a result we find a three-body resonance of the strange dibaryon system with binding energy $B~79$ MeV and width $\Gamma ~74$ MeV. The energy of the three-body resonance is found to be sensitive to the model of the $I=0$ $\overline{K}N$ interaction.

The distribution of isoscalar monopole strength in the neutron-even ${}^{112-124}\mathrm{Sn}$ isotopes has been computed using a relativistic random-phase-approximation approach. The accurately-calibrated model used here (“FSUGold”) has been successful in reproducing both ground-state observables as well as collective excitations—including the giant monopole resonance (GMR) in ${}^{90}\mathrm{Zr}$, ${}^{144}\mathrm{Sm}$, and ${}^{208}\mathrm{Pb}$. Yet this same model significantly overestimates the GMR energies in the Sn isotopes. It is argued that the question of “Why is tin so soft?” becomes an important challenge to the field and one that should be answered without sacrificing the success already achieved by several theoretical models.

Using the two-body interactions obtained from a chiral constituent quark model, we study all $\Lambda \mathit{NN}$ and $\Sigma \mathit{NN}$ states with $I=0,1,2$ and $J=1/2,3/2$ at threshold, taking into account all three-body configurations with $S$ and $D$ wave components. We constrain further the limits for the $\Lambda N$ spin-triplet scattering length $a_{1/2,1}$. Using the hypertriton binding energy, we find a narrow interval for the possible values of the $\Lambda N$ spin-singlet scattering length $a_{1/2,0}$. We find that the $\Sigma \mathit{NN}$ system has a quasibound state in the $(I,J)=(1,1/2)$ channel very near threshold with a width of about 2.1 MeV.

High spin states in ${}^{52}\mathrm{Cr}$ have been populated by means of the reaction ${}^{27}\mathrm{Al}$(${}^{28}\mathrm{Si}$$,3p$)${}^{52}\mathrm{Cr}$ at a beam energy of 70 MeV and studied with an array, consisting of eight Compton-suppressed clover germanium detectors. Eleven new γ rays have been assigned to ${}^{52}\mathrm{Cr}$ and placed in the level scheme. The level structure of ${}^{52}\mathrm{Cr}$ has been extended up to $E_x\approx 10$ MeV. Spins and parities have been assigned to many of the levels on the basis of directional correlations and linear polarization measurements. The band structures are discussed in the framework of cranked Woods-Saxon and deformed Hartree-Fock (HF) models. Both the oblate and prolate orbits are considered for $J$ projection in the HF model. The $K=0^{+}$ band is properly understood if we consider the $J$ projection from both prolate and oblate orbits and collectivity shown by the $K=4^{+}$ band to be accounted for by taking the $J$ projection from prolate HF configurations. Thus there is prolate and oblate shape coexistence in ${}^{52}\mathrm{Cr}$.

We derive coupled-cluster equations for three-body Hamiltonians. The equations for the one- and two-body cluster amplitudes are presented in a factorized form that leads to an efficient numerical implementation. We employ low-momentum two- and three-nucleon interactions and calculate the binding energy of ${}^4\mathrm{He}$. The results show that the main contribution of the three-nucleon interaction stems from its density-dependent zero-, one-, and two-body terms that result from the normal ordering of the Hamiltonian in coupled-cluster theory. The residual three-body terms that remain after normal ordering can be neglected.

The neutron-rich Fe isotopes from $A=61$ to 66 were studied through multinucleon transfer reactions by bombarding a ${}^{238}\mathrm{U}$ target with a 400 MeV ${}^{64}\mathrm{Ni}$ beam. Unambiguous identification of prompt γ rays belonging to each nucleus was achieved using coincidence relationships with the ions detected in a high-acceptance magnetic spectrometer. The new data extend our knowledge of the level structure of Fe isotopes, which is discussed in terms of the systematics of the region and compared with large-scale shell-model calculations.

The additivity principle of the extreme shell model stipulates that an average value of a one-body operator be equal to the sum of the core contribution and effective contributions of valence (particle or hole) nucleons. For quadrupole moment and angular momentum operators, we test this principle for highly deformed and superdeformed rotational bands in $A~130$ nuclei. Calculations are done in the self-consistent cranked nonrelativistic Hartree-Fock and relativistic Hartree mean-field approaches. Results indicate that the additivity principle is a valid concept that justifies the use of an extreme single-particle model in an unpaired regime typical of high angular momenta.

We study nuclear reaction cross sections for stable and unstable projectiles and targets within Glauber model, using densities obtained from various relativistic mean-field formalisms. The calculated cross sections are compared with the experimental data in some specific cases. We also evaluate the differential scattering cross sections at several incident energies and observe that the results found from various densities are similar at smaller scattering angles, whereas a systematic deviation is noticed at large angles. In general, these results agree fairly well with the experimental data.

Reaction cross sections for proton-nucleus elastic scattering are investigated within a nonrelativistic microscopic approach for the nucleon-nucleus optical model potential. Applications were made for nucleon energy ranging between 10 MeV and 1 GeV, considering both stable and unstable target nuclei. The study is based on an in-medium $g$-matrix folding optical model approach in momentum space, with the appropriate relativistic kinematic corrections needed for the higher energy applications. The effective interactions are based on realistic $\mathit{NN}$ potentials supplemented with a separable non-Hermitian term to allow optimum agreement with current $\mathit{NN}$ phase-shift analyses, particularly the inelasticities above pion production threshold. The target ground-state densities are obtained from Hartree-Fock-Bogoliubov calculations based on the finite range, density-dependent Gogny force. The evaluated reaction cross sections for proton scattering are compared with measurements and their systematics is analyzed. A simple function of the total cross sections in terms of the atomic mass number is observed at high energies. At low energies, however, discrepancies with the available data are observed, being more pronounced in the lighter systems.

The extraction of the strangeness form factors from parity-violating elastic electron-proton scattering is sensitive to the electromagnetic form factors at low $Q^2$. We provide parametrizations for the form factors and uncertainties, including the effects of two-photon exchange corrections to the extracted electromagnetic form factors. We study effect of the correlations between different form factors, in particular as they impact the parity-violating asymmetry and the extraction of the strangeness form factors. We provide a prescription to extract the strangeness form factors from the asymmetry that provides an excellent approximation of the full two-photon correction. The corrected form factors are also appropriate as input for other low-$Q$ analyses, although the effects of correlations and two-photon exchange corrections may be different.

We discuss coherent and incoherent ϕ meson photoproduction off the deuteron at low energy and small momentum transfer with the aim of checking whether the recent experimental data need for their interpretation an inclusion of exotic channels. Our analysis of the differential cross section and spin-density matrix elements shows that new data on the $\gamma D\to \varphi X$ reaction at $E_{\gamma }~2$ GeV may be understood on the basis of conventional dynamics. However, a certain ambiguity of the deviation between the model predictions and the data from the laser electron photon beamline at SPring-8 (LEPS) on the $\gamma p\to \varphi p$ reaction still remains. To make a firm conclusion about a possible manifestation of exotic channels, one has to improve the resolution of the data by providing additional information on the channels with spin- and double-spin-flip transitions which are sensitive to the properties of the photoproduction amplitude in the $\gamma p$ and $\gamma D$ reactions. This information may be used as an additional independent test of the ϕ meson photoproduction mechanism.

We measured the lifetime and the mesonic and nonmesonic decay rates of the ${}_{\Lambda }^4\mathrm{He}$ hypernucleus. The hypernuclei were created using a 750 MeV/$c$ momentum $K^{-}$ beam on a liquid ${}^4\mathrm{He}$ target by the reaction ${}^4\mathrm{He}$ $(K^{-},{\pi }^{-}){}_{\Lambda }^4\mathrm{He}$. The ${}_{\Lambda }^4\mathrm{He}$ lifetime was directly measured using protons from $\Lambda p\to np$ nonmesonic decay (also referred to as proton-stimulated decay) and was found to have a value of $\tau =245\pm 24$ ps. The mesonic decay rates were determined from the observed numbers of ${\pi }^{-}$'s and ${\pi }^{○}$'s as ${\Gamma }_{{\pi }^{-}}/{\Gamma }_{\mathrm{tot}}=0.270\pm 0.024$ and ${\Gamma }_{{\pi }^{○}}/{\Gamma }_{\mathrm{tot}}=0.564\pm 0.036$, respectively, and the values of the proton- and neutron-stimulated decay rates were extracted as ${\Gamma }_p/{\Gamma }_{\mathrm{tot}}=0.169\pm 0.019$ and ${\Gamma }_n/{\Gamma }_{\mathrm{tot}}⩽0.032$ (95% CL), respectively. The effects of final-state interactions and possible three-body $\Lambda NN$ decay contributions were studied in the context of a simple model of nucleon-stimulated decay. Nucleon-nucleon coincidence events were observed and were used in the determination of the nonmesonic branching fractions. The implications of the results of this analysis were considered for the empirical $\Delta I=\frac{1}{2}$ rule and the decay rates of the ${}_{\Lambda }^4\mathrm{H}$ hypernucleus.