We calculated the exclusive $f_1(1285)$ meson photoproduction cross section at an energy of a few GeV within the Regge approach. The calculation shows that the cross section is sizable, being in the range of 100 nb, and much larger than the expected cross section of the $\eta (1295)$ meson photoproduction at the same energy. These two facts make it possible to use this reaction to study the poor known properties of the $f_1(1285)$ meson in the JLab kinematics.

A detailed spectroscopic study of the neutron-deficient isotope ${}^{181}\mathrm{Tl}$ and the daughter of its $\alpha$ decay, ${}^{177}\mathrm{Au}$, has been performed in the complete fusion reaction ${}^{40}\mathrm{Ca}+{}^{144}\mathrm{Sm}\to {}^{184}\mathrm{Pb}{}^{*}$ at the velocity filter SHIP (GSI). The mass excess, excitation energy, and decay scheme of the isomeric 1.40(3) ms, $9/2^{-}$ intruder state in ${}^{181}\mathrm{Tl}$ have been established for the first time. These results solve a long-standing puzzle of the unrealistically large reduced $\alpha$-decay width of this isomer. Based on this, the previously unknown masses of the long-lived isomeric states in ${}^{177}\mathrm{Au}$ and ${}^{173}\mathrm{Ir}$ have been derived. In turn, it now allows the excitation energies of previously identified bands in ${}^{177}\mathrm{Au}$ and ${}^{173}\mathrm{Ir}$ to be deduced and compared with theoretical predictions. First measurements of $\alpha$-decay branching ratios for ${}^{181}\mathrm{Tl}{}^m$ and ${}^{177}\mathrm{Au}{}^{m,g}$ are also reported.

We formulate a new scheme of the Hartree-Fock-Bogoliubov mean-field theory applicable to weakly bound and pair-correlated deformed nuclei using the coordinate-space Green's function technique. On the basis of a coupled-channel representation of the quasiparticle wave function expanded in terms of the partial waves, we impose the correct boundary condition of the asymptotically out-going waves on the continuum quasiparticle states. We perform numerical analysis for ${}^{38}\mathrm{Mg}$ to illustrate properties of the continuum quasiparticle states and the pair correlation in deformed nuclei near the neutron drip line.

We consider high-energy quasifree single- and two-proton knockout reactions induced by electrons and protons and address the question of what target-nucleus densities can be effectively probed after correcting for nuclear attenuation (initial- and final-state interactions). Our calculations refer to ejected proton kinetic energies of 1.5 GeV, the reactions $(e,e^{\text{'}}p)$, $(\gamma ,\mathit{pp})$, and $(p,2p)$, and a carbon target. It is shown that each of the three reactions is characterized by a distinctive sensitivity to the density of the target nucleus. The bulk of the $(\gamma ,\mathit{pp})$ strength stems from the high-density regions in the deep nuclear interior. Despite the strong attenuation, sizable densities can be probed by $(p,2p)$ reactions provided that the energy resolution allows one to pick nucleons from $s$ orbits. The effective mean densities that can be probed in high-energy $(e,e^{\text{'}}p)$ reactions is of the order of 30%–50% of the nuclear saturation density.

Absolute electromagnetic transition probabilities in ${}^{196}\mathrm{Po}$ have been measured using the recoil distance Doppler-shift technique. The lifetimes of the three lowest yrast states in ${}^{196}\mathrm{Po}$ were extracted from singles γ-ray spectra by using the recoil-decay tagging method. In addition, configuration mixing calculations of angular momentum projected mean-field states have been carried out for ${}^{196}\mathrm{Po}$. The present study sheds light on the onset of collectivity and mixing of competing structures in neutron-deficient Po nuclei.

Lifetimes of yrast states in ${}^{180}\mathrm{Hg}$ up to the $8^{+}$ state and of the $9^{-}$ state have been extracted from recoil-decay tagged $\gamma$-ray spectra by using the recoil distance Doppler-shift method. In addition, lifetimes of yrast states up to the ${10}^{+}$ state in ${}^{182}\mathrm{Hg}$ have been extracted from recoil-gated $\gamma \gamma$-coincidence spectra. The present study addresses the evolution of collectivity of two competing shapes in neutron-deficient Hg nuclei as a function of $A$ and the configuration mixing at low spin.

The charged-current quasielastic scattering of muon neutrino on a carbon target is calculated for neutrino energy up to 2.8 GeV using the relativistic distorted-wave impulse approximation with relativistic optical potential, which was earlier successfully applied to describe the electron-nucleus data. We studied both neutrino and electron processes and have shown that the reduced exclusive cross sections for neutrino and electron scattering are similar. The nuclear and axial vector mass effects on the shape of $Q^2$ distribution have also been studied. The comparison of the (anti-)neutrino total cross sections per (proton)neutron, calculated for the carbon and oxygen targets, shows the cross sections for oxygen to be lower than those for carbon. A significant nuclear model dependence of inclusive and total cross sections for energy about 1 GeV was found.

We analyze the effect of plasma screening on nuclear reaction rates in dense matter composed of atomic nuclei of one or two types. We perform semiclassical calculations of the Coulomb barrier penetrability taking into account a radial mean-field potential of plasma ions. The mean-field potential is extracted from the results of extensive Monte Carlo calculations of radial pair distribution functions of ions in binary ionic mixtures. We calculate the reaction rates in a wide range of plasma parameters and approximate these rates by an analytical expression that is expected to be applicable to multicomponent ion mixtures. Also, we analyze Gamow-peak energies of reacting ions in various nuclear burning regimes. For illustration, we study nuclear burning in ${}^{12}\mathrm{C}$-${}^{16}\mathrm{O}$ mixtures.

We investigate a large angle photodisintegration of two nucleons from the ${}^3\mathrm{He}$ nucleus within the framework of the hard rescattering model (HRM). In the HRM a quark of one nucleon knocked out by an incoming photon rescatters with a quark of the other nucleon leading to the production of two nucleons with large relative momentum. Assuming the dominance of the quark-interchange mechanism in a hard nucleon-nucleon scattering, the HRM allows the expression of the amplitude of a two-nucleon breakup reaction through the convolution of photon-quark scattering, $\mathit{NN}$ hard scattering amplitude, and nuclear spectral function, which can be calculated using a nonrelativistic ${}^3\mathrm{He}$ wave function. The photon-quark scattering amplitude can be explicitly calculated in the high energy regime, whereas for $\mathit{NN}$ scattering one uses the fit of the available experimental data. The HRM predicts several specific features for the hard breakup reaction. First, the cross section will approximately scale as $s^{-11}$. Second, the $s^{11}$ weighted cross section will have the shape of energy dependence similar to that of $s^{10}$ weighted $\mathit{NN}$ elastic scattering cross section. Also one predicts an enhancement of the $\mathit{pp}$ breakup relative to the $\mathit{pn}$ breakup cross section as compared to the results from low energy kinematics. Another result is the prediction of different spectator momentum dependencies of $\mathit{pp}$ and $\mathit{pn}$ breakup cross sections. This is due to the fact that the same-helicity $\mathit{pp}$-component is strongly suppressed in the ground state wave function of ${}^3\mathrm{He}$. Because of this suppression the HRM predicts significantly different asymmetries for the cross section of polarization transfer $\mathit{NN}$ breakup reactions for circularly polarized photons. For the $\mathit{pp}$ breakup this asymmetry is predicted to be zero while for the $\mathit{pn}$ it is close to $\frac{2}{3}$.

The quark combination mechanism of QGP hadronization is applied to nucleus-nucleus collisions at the top energy available at the CERN Super Proton Synchrotron (SPS). The yields, rapidity, and transverse momentum distributions of identified hadrons in most central $\mathrm{Pb}+\mathrm{Pb}$ collisions at $\sqrt{s_{\mathit{NN}}}=17.3$ GeV are systematically studied. The calculated results agree with the experimental data from the NA49 Collaboration. The longitudinal and transverse collective flows and strangeness of the hot and dense quark matter produced in nucleus-nucleus collisions at the top SPS energy are investigated. It is found that the collective flow of strange quarks is stronger than that for light quarks; this result is similar to that obtained at energies currently available at the BNL Relativistic Heavy Ion Collider, and the strangeness is almost the same as those at $\sqrt{s_{\mathit{NN}}}=62.4$, 130, and 200 GeV.

Elastic backscattering measurements were performed for the weakly bound nucleus ${}^6\mathrm{Li}$ on a ${}^{28}\mathrm{Si}$ target at sub- and near-barrier energies (0.6 to 1.3 V${}_{C.B.}$). Excitation functions of elastic scattering cross sections were measured at ${150}^{°}$ and ${170}^{°}$ and the corresponding ratios to Rutherford scattering and relevant barrier distributions were formed. The results are discussed in terms of the potential threshold anomaly and the reaction mechanisms involved.

The combined data from three fusion-evaporation reaction experiments have been utilized to investigate the semi-magic nucleus ${}_{28}^{58}{\mathrm{Ni}}_{30}$. To detect $\gamma$ rays in coincidence with evaporated particles, the Ge-detector array Gammasphere was used in conjunction with the charged-particle detectors Microball and LuWuSiA (the Lund Washington University Silicon Array), and a neutron detector array. The results yield a significantly extended level scheme of ${}^{58}\mathrm{Ni}$ comprising some 340 $\gamma$-ray transitions and include a total of at least 14 discrete particle decays into excited states of the daughter nuclei ${}^{54}\mathrm{Fe}$ and ${}^{57}\mathrm{Co}$. The level scheme is compared with large-scale shell-model calculations and cranked Nilsson-Strutinsky calculations.

Analytical expressions for the saturation density of asymmetric nuclear matter as well as its binding energy and incompressibility at saturation density are given up to fourth order in the isospin asymmetry $\delta =({\rho }_n-{\rho }_p)/\rho$ using 11 characteristic parameters defined by the density derivatives of the binding energy per nucleon of symmetric nuclear matter, the symmetry energy $E_{\mathrm{sym}}\hspace{0.5em}(\rho )$, and the fourth-order symmetry energy $E_{\mathrm{sym},4}(\rho )$ at normal nuclear density ${\rho }_0$. Using an isospin- and momentum-dependent modified Gogny interaction (MDI) and the Skyrme-Hartree-Fock (SHF) approach with 63 popular Skyrme interactions, we have systematically studied the isospin dependence of the saturation properties of asymmetric nuclear matter, particularly the incompressibility $K_{\mathrm{sat}}(\delta )=K_0+K_{\mathrm{sat},2}{\delta }^2+K_{\mathrm{sat},4}{\delta }^4+O({\delta }^6)$ at saturation density. Our results show that the magnitude of the higher order $K_{\mathrm{sat},4}$ parameter is generally small compared to that of the $K_{\mathrm{sat},2}$ parameter. The latter essentially characterizes the isospin dependence of the incompressibility at saturation density and can be expressed as $K_{\mathrm{sat},2}=K_{\mathrm{sym}}-6L-\frac{J_0}{K_0}L$, where $L$ and $K_{\mathrm{sym}}$ represent, respectively, the slope and curvature parameters of the symmetry energy at ${\rho }_0$ and $J_0$ is the third-order derivative parameter of symmetric nuclear matter at ${\rho }_0$. Furthermore, we have constructed a phenomenological modified Skyrme-like (MSL) model that can reasonably describe the general properties of symmetric nuclear matter and the symmetry energy predicted by both the MDI model and the SHF approach. The results indicate that the higher order $J_0$ contribution to $K_{\mathrm{sat},2}$ generally cannot be neglected. In addition, it is found that there exists a nicely linear correlation between $K_{\mathrm{sym}}$ and $L$ as well as between $J_0/K_0$ and $K_0$. These correlations together with the empirical constraints on $K_0,L,E_{\mathrm{sym}}\hspace{0.5em}({\rho }_0)$, and the nucleon effective mass lead to an estimate of $K_{\mathrm{sat},2}=-370\pm 120$ MeV.

The Russian-American experiment SAGE began to measure the solar neutrino capture rate with a target of gallium metal in December 1989. Measurements have continued with only a few brief interruptions since that time. In this article we present the experimental improvements in SAGE since its last published data summary in December 2001. Assuming the solar neutrino production rate was constant during the period of data collection, combined analysis of 168 extractions through December 2007 gives a capture rate of solar neutrinos with energy more than 233 keV of $65.4_{-3.0}^{+3.1}$ (stat) ${}_{-2.8}^{+2.6}$ (syst) SNU. The weighted average of the results of all three Ga solar neutrino experiments, SAGE, Gallex, and GNO, is now $66.1\pm 3.1$ SNU, where statistical and systematic uncertainties have been combined in quadrature. During the recent period of data collection a new test of SAGE was made with a reactor-produced ${}^{37}\mathrm{Ar}$ neutrino source. The ratio of observed to calculated rates in this experiment, combined with the measured rates in the three prior ${}^{51}\mathrm{Cr}$ neutrino-source experiments with Ga, is $0.87\pm 0.05$. A probable explanation for this low result is that the cross section for neutrino capture by the two lowest-lying excited states in ${}^{71}\mathrm{Ge}$ has been overestimated. If we assume these cross sections are zero, then the standard solar model including neutrino oscillations predicts a total capture rate in Ga in the range of 63 SNU to 66 SNU with an uncertainty of about 4%, in good agreement with experiment. We derive the current value of the neutrino flux produced in the Sun by the proton-proton fusion reaction to be ${\varphi }_{\mathit{pp}}^{\odot }=(6.0\pm 0.8)\times {10}^{10}/({\mathrm{cm}}^2\hspace{0.5em}\mathrm{s})$, which agrees well with the $\mathit{pp}$ flux predicted by the standard solar model. Finally, we make several tests and show that the data are consistent with the assumption that the solar neutrino production rate is constant in time.

Isospin-breaking effects have been studied for the first time in $T=\frac{3}{2}$ isobaric analog states. Gamma decays have been observed from $T_z=-\frac{3}{2}$ nuclei, ${}^{49}\mathrm{Fe}$ and ${}^{53}\mathrm{Ni}$, presented here in new level schemes, and mirror energy differences have been computed following observation of analog states in ${}^{49}\mathrm{V}$ and ${}^{53}\mathrm{Mn}$, respectively. Shell-model calculations in the $\mathit{fp}$ shell are in good agreement with the data and reveal the importance of non-Coulomb isospin-breaking effects in $T=\frac{3}{2}$ isobaric analog states. A two-step fragmentation process was developed to allow access to highly proton-rich nuclei and to produce each member of a mirror pair via mirrored fragmentation of a ${}^{56}\mathrm{Ni}$ secondary beam. This work represents the first study using this technique and demonstrates the power of this approach for future studies of isobaric analog states in very proton-rich systems.

Nuclei are propitious tools to investigate the role of the superfluidity in the compressibility of a Fermionic system. The centroid of the Giant Monopole Resonance (GMR) in Tin isotopes is predicted using a constrained Hartree-Fock Bogoliubov approach, ensuring a full self-consistent treatment. Superfluidity is found to favour the compressibitily of nuclei. Pairing correlations explain why doubly magic nuclei such as ${}^{208}\mathrm{Pb}$ are stiffer compared to open-shell nuclei. Fully self-consistent predictions of the GMR on an isotopic chain should be the way to microscopically extract both the incompressibility and the density dependence of a given energy functional. The macroscopic extraction of $K_{\mathit{sym}}$, the asymmetry incompressibility, is questioned. Investigations of the GMR in unstable nuclei are called for. Pairing gap dependence of the nuclear matter incompressibility should also be investigated.