We present new results concerning the electromagnetic form factors of the nucleon using a relativistic version of the hypercentral constituent quark model and a relativistic current.

Self-consistent Skyrme-Hartree-Fock plus BCS calculations are performed to generate potential energy curves (PECs) in various chains of Pd, Xe, Ba, Nd, Sm, Gd, and Dy isotopes. The evolution of shapes with the number of nucleons is studied in a search for signatures of E(5) and X(5) critical point symmetries. It is shown that the energy barriers in the PECs are determined to a large extent by the treatment of the pairing correlations.

Conversion electrons from ${}^{208}\mathrm{Bi}$ have been measured using singles and coincidence techniques with the ${}^{208}\mathrm{Pb}$($p,n$)${}^{208}\mathrm{Bi}$ reaction at 9 MeV. The new information on multipolarities and spins complements that available from recent $\gamma \text{−}\gamma$-coincidence studies with the same reaction [Boutachkov et al., Nucl. Phys. A768, 22 (2006)]. The results on electromagnetic decays taken together with information on spectroscopic factors from earlier single-particle transfer reaction measurements represent an extensive data set on the properties of the one-proton one-neutron-hole states below 3 MeV, a spectrum which is virtually complete. Comparison of the experimental observables, namely, energies, spectroscopic factors, and γ-branching ratios, with those calculated within the shell model allows extraction of the matrix elements of the shell model residual interaction. More than 100 diagonal and nondiagonal elements can be determined in this way, through a least squares fit to the experimental data. This adjustment of the interaction significantly affects the calculated properties of the γ-ray transitions. Nevertheless, the matrix elements thus obtained are remarkably similar to those of a realistic interaction calculated from free-nucleon scattering. Characteristic features of the interaction are discussed.

The recent CLAS 2005, SAPHIR 2003, LEPS, and the old, pre-1972, data on $K^{+}\Lambda$ photoproduction are compared with theoretical calculations in the energy region of $E_{\gamma }^{\mathrm{lab}}<2.6$ GeV in order to learn about their mutual consistency. The isobaric models Kaon-Maid and Saclay-Lyon, along with new fits to the CLAS data, are utilized in this analysis. The SAPHIR 2003 data are shown to be coherently shifted down with respect to the CLAS, LEPS, and pre-1972 data, especially at forward kaon angles. The CLAS, LEPS, and pre-1972 data in the forward hemisphere can be described satisfactorily by using the isobaric model without hadronic form factors. The inclusion of the hadronic form factors yields a strong suppression of the cross sections at small kaon angles and c.m. energies larger than 1.9 GeV, which is not observed in the existing experimental data. We demonstrate that the discrepancy between the CLAS and SAPHIR data has a significant impact on the predicted values of the mass and width of the “missing resonance” $D_{13}(1895)$ in the Kaon-Maid model.

The positive-parity yrast states in the ${}^{89}\mathrm{Rb}$, ${}^{92}\mathrm{Y}$, and ${}^{93}\mathrm{Y}$ nuclei were studied using γ-ray spectroscopy with heavy-ion induced reactions. In the multinucleon transfer reactions ${}^{208}\mathrm{Pb}+{}^{90}\mathrm{Zr}$ (590 MeV) and ${}^{238}\mathrm{U}+{}^{82}\mathrm{Se}$ (505 MeV), several γ-ray transitions were identified in these nuclei by means of coincidences between recoiling ions identified with the PRISMA spectrometer and γ rays detected with the CLARA γ-ray array in thin target experiments. Level schemes were subsequently determined from triple-γ coincidences recorded with the GASP array in a thick target experiment, in the reactions produced by a 470 MeV ${}^{82}\mathrm{Se}$ beam with a ${}^{192}\mathrm{Os}$ target. The observed level schemes are compared to shell-model calculations.

The mean-lifetimes, τ, of various medium-spin excited states in ${}^{103}\mathrm{Pd}$ and ${}^{106,107}\mathrm{Cd}$ have been deduced using the Recoil Distance Doppler Shift technique and the Differential Decay Curve Method. In ${}^{106}\mathrm{Cd}$, the mean-lifetimes of the $I^{\pi }={12}^{+}$ state at $E_x=5418$ keV and the $I^{\pi }={11}^{-}$ state at $E_x=4324$ keV have been deduced as 11.4(17)ps and 8.2(7)ps, respectively. The associated ${\beta }_2$ deformation within the axially-symmetric deformed rotor model for these states are 0.14(1) and 0.14(1), respectively. The ${\beta }_2$ deformation of 0.14(1) for the $I^{\pi }={12}^{+}$ state in ${}^{106}\mathrm{Cd}$ compares with a predicted ${\beta }_2$ value from total Routhian surface (TRS) calculations of 0.17. In addition, the mean-lifetimes of the yrast $I^{\pi }={\frac{15}{2}}^{-}$ states in ${}^{103}\mathrm{Pd}$ (at $E_x=1262$ keV) and ${}^{107}\mathrm{Cd}$ (at $E_x=1360$ keV) have been deduced to be 31.2(44)ps and 31.4(17)ps, respectively, corresponding to ${\beta }_2$ values of 0.16(1) and 0.12(1) assuming axial symmetry. Agreement with TRS calculations are good for ${}^{103}\mathrm{Pd}$ but deviate for that predicted for ${}^{107}\mathrm{Cd}$.

Cross sections were measured by the activation technique for the nuclear reactions ${}^{141}\mathrm{Pr}$($p,n$)${}^{141}\mathrm{Nd}$${}^m$,${}^{141}\mathrm{Pr}$($p,3n$)${}^{139}\mathrm{Nd}$${}^m,{}^{\mathrm{nat}}$Ce(${}^3\mathrm{He}$,$\mathit{xn}$)${}^{141}\mathrm{Nd}$${}^m$, and ${}^{\mathrm{nat}}$Ce(${}^3\mathrm{He}$,$\mathit{xn}$)${}^{139}\mathrm{Nd}$${}^m$ up to proton energies of 44 MeV and ${}^3\mathrm{He}$-particle energies of 35 MeV. Using the present data and some of our earlier experimental results the isomeric cross-section ratios for the nuclide pairs ${}^{139}\mathrm{Nd}$${}^{m,g}$ and ${}^{141}\mathrm{Nd}$${}^{m,g}$ were calculated. The experimental data were compared with the results of nuclear model calculations using the code STAPRE, which combines the statistical and precompound formalisms. In general the experimentally determined excitation functions as well as the isomeric cross-section ratios could be described by the theory within the limits of experimental uncertainties, but using relatively low values of $\eta$ [i.e., the ratio of the effective moment of inertia to the rigid-body moment of inertia (${\Theta }_{\mathrm{eff}}/{\Theta }_{\mathrm{rig}}$)]. The mass dependence of $\eta$ could be confirmed.

The continuum discretized coupled channels (CDCC) method is compared with the exact solution of the three-body Faddeev equations in momentum space. We present results for (i) elastic and breakup observables of $d+$${}^{12}\mathrm{C}$ at $E_d=56$ MeV, (ii) elastic scattering of $d+$${}^{58}\mathrm{Ni}$ at $E_d=80$ MeV, and (iii) elastic, breakup, and transfer observables for ${}^{11}\mathrm{Be}$$+p$ at $E_{{}^{11}\mathrm{Be}}/A=38.4$ MeV. Our comparative studies show that in the first two cases, the CDCC method is a good approximation of the full three-body Faddeev solution, but for the ${}^{11}\mathrm{Be}$ exotic nucleus, depending on the observable or the kinematic regime, it may miss some of the dynamic three-body effects that appear through the explicit coupling to the transfer channel.

As a first step to analyze the electromagnetic meson production reactions in the nucleon resonance region, the parameters of the hadronic interactions of a dynamical coupled-channels model, developed in Physics Reports 439, 193 (2007), are determined by fitting the $\pi N$-scattering data. The channels included in the calculations are $\pi N,\eta N$, and $\pi \pi N$, which has $\pi \Delta ,\rho N$, and $\sigma N$ resonant components. The nonresonant meson-baryon interactions of the model are derived from a set of Lagrangians by using a unitary transformation method. One or two bare excited nucleon states in each of $S,P,D$, and $F$ partial waves are included to generate the resonant amplitudes in the fits. The parameters of the model are first determined by fitting as much as possible the empirical $\pi N$ elastic-scattering amplitudes of SAID up to 2 GeV. We then refine and confirm the resulting parameters by directly comparing the predicted differential cross section and target polarization asymmetry with the original data of the elastic ${\pi }^{\pm }p\to {\pi }^{\pm }p$ and charge-exchange ${\pi }^{-}p\to {\pi }^{0}n$ processes. The predicted total cross sections of $\pi N$ reactions and $\pi N\to \eta N$ reactions are also in good agreement with the data. Applications of the constructed model in analyzing the electromagnetic meson production data as well as the future developments are discussed.

We have measured in-beam γ rays in the neutron-rich ${}^{246}{\mathrm{Pu}}_{152}$ and ${}^{245}{\mathrm{Pu}}_{151}$ nuclei by means of ${}^{244}\mathrm{Pu}$(${}^{18}\mathrm{O}$, ${}^{16}\mathrm{O}$)${}^{246}\mathrm{Pu}$ and ${}^{244}\mathrm{Pu}$(${}^{18}\mathrm{O}$, ${}^{17}\mathrm{O}$)${}^{245}\mathrm{Pu}$ neutron transfer reactions, respectively. The γ rays emitted from ${}^{246}\mathrm{Pu}$ (${}^{245}\mathrm{Pu}$) were identified by selecting the kinetic energy of scattered ${}^{16}\mathrm{O}$ (${}^{17}\mathrm{O}$) detected by Si $\Delta E-E$ detectors. The ground-state band of ${}^{246}\mathrm{Pu}$ was established up to the ${12}^{+}$ state. We have found that the shell gap of $N=152$ is reduced in energy with decreasing atomic number by extending the systematics of the one-quasiparticle energies in $N=151$ nuclei into those in ${}^{245}\mathrm{Pu}$. This reduction of the shell gap clearly affects the $2^{+}$ energy of the ground-state band of ${}^{246}\mathrm{Pu}$.

The cross sections of the ${}^{70}\mathrm{Ge}$($p,\gamma$)${}^{71}\mathrm{As}$ and ${}^{76}\mathrm{Ge}$($p,n$)${}^{76}\mathrm{As}$ reactions have been measured with the activation method in the Gamow window for the astrophysical $p$ process. The experiments were carried out at the Van de Graaff and cyclotron accelerators of ATOMKI. The cross sections have been derived by measuring the decay γ-radiation of the reaction products. The results are compared to the predictions of Hauser-Feshbach statistical model calculations using the code NON-SMOKER. Good agreement between theoretical and experimental $S$ factors is found. Based on the new data, modifications of the optical potential used for low-energy protons are discussed.

By exploiting Coulomb dissociation of high-energy radioactive beams of the neutron-rich nuclei ${}^{129-132}\mathrm{Sn}$ and ${}^{133,134}\mathrm{Sb}$, their dipole-strength distributions have been measured. A sizable fraction of “pygmy” dipole strength, energetically located below the giant dipole resonance, is observed in all of these nuclei. A comparison with available pygmy resonance data in stable nuclei (${}^{208}\mathrm{Pb}$ and $N=82$ isotones) indicates a trend of strength increasing with the proton-to-neutron asymmetry. On theoretical grounds, employing the RQRPA approach, a one-to-one correlation is found between the pygmy strength and parameters describing the density dependence of the nuclear symmetry energy, and in turn with the thicknesses of the neutron skins. On this basis, by using the experimental pygmy strength, parameters of the nuclear symmetry energy ($a_4=32.0\pm 1.8$ MeV and $p_o=2.3\pm 0.8$ MeV/fm${}^3$) are deduced as well as neutron-skin thicknesses $R_n-R_p$ of $0.24\pm 0.04$ fm for ${}^{132}\mathrm{Sn}$ and of $0.18\pm 0.035$ fm for ${}^{208}\mathrm{Pb}$, both doubly magic nuclei. Astrophysical implications with regard to neutron stars are briefly addressed.

First measurement of subthreshold Σ(1385) production is presented. Experimental data are presented for Al+Al reactions at $1.9A$ GeV measured with the FOPI detector at SIS/GSI. The $\Sigma (1385)/\Lambda$ ratio is found to be in good agreement with the transport and statistical model predictions. The results allow for a better understanding of subthreshold strangeness production and strangeness exchange reaction which is the dominant process for $K^{-}$ production below and close-to threshold.

Kaon electroproduction from light nuclei and hydrogen, using ${}^1\mathrm{H}$, ${}^2\mathrm{H}$, ${}^3\mathrm{He}$, ${}^4\mathrm{He}$, and carbon targets has been measured at the Thomas Jefferson National Accelerator Facility. The quasifree angular distributions of Λ and Σ hyperons were determined at $Q^2=0.35$ (GeV/$c$)${}^2$ and $W=1.91$ GeV. Electroproduction on hydrogen was measured at the same kinematics for reference.

The tensor properties of the algebra generators and the basis are determined in respect to the reduction chain Sp($12,R$) ⊃ U(6) ⊃ U(3) ⊗ U(2) ⊃ O(3) ⊗ U(1), which defines one of the dynamical symmetries of the interacting vector boson model. The action of the Sp($12,R$) generators as transition operators between the basis states is presented. Analytical expressions for their matrix elements in the symmetry-adapted basis are obtained. As an example the matrix elements of the $E2$ transition operator between collective states of the ground band are determined and compared with the experimental data for the corresponding intraband transition probabilities of nuclei in the actinide and rare-earth region. On the basis of this application the important role of the symplectic extension of the model is analyzed.

We calculate the doublet and quartet neutron-deuteron scattering lengths using a nonlocal nucleon-nucleon interaction fully derived from quark-quark interactions. We use as input the $\mathit{NN}{}^1{S}_0$ and ${}^3{S}_1\text{−}{}^3{D}_1$ partial waves. Our result for the quartet scattering length agrees well with the experimental value but the result for the doublet scattering length does not. However, if we take the result for the doublet scattering length together with the one for the triton binding energy they agree well with the so-called Phillips line.

We establish the bridge between the commonly used Nabetani-Ogaito-Sato-Kishimoto (NOSK) formula for the asymmetry parameter $a_{\Lambda }$ in the $\overrightarrow{\Lambda }p\to \mathit{np}$ emission of polarized hypernuclei, and the shell-model (SM) formalism for finite hypernuclei. We demonstrate that the $s$-wave approximation leads to a SM formula for $a_{\Lambda }$ that is as simple as the NOSK one and that reproduces the exact results for ${}_{\Lambda }^5$He and ${}_{\Lambda }^{12}$C better than initially expected. The simplicity achieved here is indeed remarkable. The new formalism makes the theoretical evaluation of $a_{\Lambda }$ more transparent and explains clearly why the one-meson exchange model is unable to account for the experimental data of ${}_{\Lambda }^5$He.

We study two recently proposed equations of state obtained from high-temperature QCD and show how they can be adapted to use them for making predictions for relativistic heavy ion collisions. The method involves extracting equilibrium distribution functions for quarks and gluons from the equation of state (EOS), which in turn will allow a determination of the transport and other bulk properties of the quark gluon-plasma. Simultaneously, the method also yields a quasiparticle description of interacting quarks and gluons. The first EOS is perturbative in the QCD coupling constant and has contributions of $O(g^5)$. The second EOS is an improvement over the first, with contributions up to $O[g^6\ln (1/g)]$; it incorporates the nonperturbative hard thermal contributions. The interaction effects are shown to be captured entirely by the effective chemical potentials for the gluons and the quarks, in both cases. The chemical potential is seen to be highly sensitive to the EOS. As an application, we determine the screening lengths, which are, indeed, the most important diagnostics for QGP. The screening lengths are seen to behave drastically differently depending on the EOS considered and therefore yield a way to distinguish the two equations of state in heavy ion collisions.