The two-proton stripping reaction ${(}^{16}$O${,}^{14}$C) has been measured on some of the even N=28 isotones: ${}_{}{}^{48}{}_{}{}^{}\mathrm{Ca}$, ${}_{}{}^{52}{}_{}{}^{}\mathrm{Cr}$ at 160 MeV and ${}_{}{}^{50}{}_{}{}^{}\mathrm{Ti}$, ${}_{}{}^{54}{}_{}{}^{}\mathrm{Fe}$ at 150 MeV bombarding energy. States of excitation up to 10 MeV have been extracted over an angular range 4°–10° in the center-of-mass system. The angular distributions have been compared to transfer calculations that consist of both the simultaneous and successive transfer processes and were performed in exact finite range. Only the simple, (1$f_{7/2}$${)}^n$ dominated states have been analyzed to investigate whether this reaction mechanism can account for the data. The absolute magnitude of the ${}_{}{}^{48}{}_{}{}^{}\mathrm{Ca}$${(}^{16}$O${,}^{14}$C) ${}_{}{}^{50}{}_{}{}^{}\mathrm{Ti}$ ground-state reaction has been reproduced. However, the experimental and theoretical uncertainties are larger than the sensitivity to different structure descriptions of the target/residual nuclei. Therefore, we have not been able to probe the pairing correlations in the ground state of ${}_{}{}^{50}{}_{}{}^{}\mathrm{Ti}$. The calculations fail to reproduce the magnitude of the transitions to other states in ${}_{}{}^{50}{}_{}{}^{}\mathrm{Ti}$. Similar problems occurred for the other reactions, leading to ${}_{}{}^{52}{}_{}{}^{}\mathrm{Cr}$, ${}_{}{}^{54}{}_{}{}^{}\mathrm{Fe}$, and ${}_{}{}^{56}{}_{}{}^{}\mathrm{Ni}$. The discrepancy ranges from a factor of 2 to nearly 30. In addition, there are phase differences between the calculations and the measured cross sections. Some systematics of the disagreement are investigated. It is suggested that the simultaneous/successive mechanism can account for the data when the transition is kinematically well matched. In cases of poor matching, inelastic/transfer mechanisms may be kinematically enhanced and contribute to the cross section with significant strength.

A detailed investigation of the excited states of ${}_{}{}^{13}{}_{}{}^{}\mathrm{C}$ below 10 MeV excitation energy by means of high-resolution electron scattering at momentum transfers between 0.4 and 2.4 ${\mathrm{fm}}^{\mathrm{-}1}$ has been performed. Additional data taken for excitation energies between 10 and 22 MeV are also selectively discussed. Up to an excitation energy of 12 MeV the data are compared with the results of a shell-model calculation which uses the full 0ħω and 1ħω model spaces together with effective one-body transition operators.

States up to $I^{\pi }$${=(20\mathrm{}}^{+}$) have been established in the neutron-deficient ${}_{}{}^{140}{}_{}{}^{}\mathrm{Gd}$ nucleus by means of the ${}_{}{}^{92}{}_{}{}^{}\mathrm{Mo}$${(}^{50}$Cr, 2pγ) reaction. At a rotational frequency ħω=0.30 MeV, the ground-state band is crossed by a band built on the aligned [π$h_{11/2}$${]}^2$ two-quasiproton configuration. This proton-aligned band was observed from spins ${10}^{+}$ to (${20}^{+}$). A second ${10}^{+}$ state was established which is most likely built on the [ν$h_{11/2}$${]}^2$ two-quasineutron configuration. The γ-vibrational band was observed up to $I^{\pi }$${=(8\mathrm{}}^{+}$) with the odd- and even-spin members exhibiting a pronounced signature splitting. The results are compared to those found recently for the lighter ${}_{}{}^{136}{}_{}{}^{}\mathrm{Nd}$ and ${}_{}{}^{138}{}_{}{}^{}\mathrm{Sm}$ N=76 isotones.

A phase-space description of the collision between two slabs of nuclear-matter is presented. Anisotropic distortions of the Fermi surface are included in the distribution function. The present results are compared with the predictions of the time-dependent Hartree-Fock and hydrodynamical approaches.

The possibilities of the occurrence of liquid-gas phase transition in nuclear matter and finite nuclei are investigated in the framework of temperature-dependent Hartree-Fock theory employing the finite-range Brink-Boeker effective interaction. The equation of state at subnuclear density is obtained. It is found that for infinite nuclear matter critical temperature for the phase transition is substantially reduced because of the finite-range nature of the force as compared to those obtained using zero-range forces. When finite-size effect and Coulomb force are taken into account, critical temperature is found to be around 8 MeV.

An equation of state for asymmetric nuclear matter is derived and used to investigate the instability of hot nuclei caused by the Coulomb force. This equation of state takes into consideration the effect of degeneracy of the Fermi system. The nucleus is treated as a liquid drop with a sharp edge and a surface tension. Both the liquid and the surrounding vapor are described by the derived equation of state. The equations describing the coexistence between the drop and the vapor are determined and solved. The instability of these hot liquid drops at temperatures above a certain limiting value is verified by the absence of any real solution of the coexistence equations at such temperatures. The value of the limiting temperature depends on the nucleus but is always less than the critical temperature of nuclear matter. It is found that high-order degeneracy effects as well as symmetry energy corrections must be included in the calculation if meaningful information about the bulk and surface properties of hot nuclear matter is to be extracted from any measurements of the limiting temperature.

The ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$(e,e’p) reaction at the delta resonance has been measured for protons detected parallel to the momentum transfer at two kinematical situations: at the maximum and the low-energy-loss side of the peak. The cross section was measured for missing energies up to 320 and 220 MeV, respectively. In the missing energy spectrum two distinct structures are observed, which correspond to multinucleon knockout and quasifree pion production processes. In addition, there is a remnant of the quasifree knockout process.

Antiproton and antilambda annihilations involving several nucleons at the same time are assumed and arguments in favor of such processes are discussed. A statistical model for annihilation on one or several nucleons is studied. It is shown to give very good results for annihilation on one nucleon. The predictions of such a model for annihilation on several nucleons are discussed extensively. The most important of those is the enhancement of the strange particle yield. Other predictions are made for remarkable two-body channels and in particular for the mesonless annihilation n${¯}^3$He→pp. A geometrical model is made to estimate the probability of having annihilation on several nucleons in nuclei. Finally, the relationship between our statistical approach and current dynamical models is discussed.

A naive two-amplitude model, in which one amplitude is independent of energy and the other is &, gives an excellent fit to the energy dependence of the double charge exchange cross section on ${}_{}{}^{18}{}_{}{}^{}\mathrm{O}$.

The muonic atom energies of the 2p-1s and the 3d-2p transitions were measured with a statistical accuracy of better than ±70 and ±40 eV, respectively, for ${}_{}{}^{123,124,125,126,128,130}{}_{}{}^{}\mathrm{Te}$. The values for the Barrett equivalent nuclear radii $R_k$,α and for the root-mean-square radii and their differences were calculated first from muonic data alone and second with the addition of published optical data. The latter data provided the radii of ${}_{}{}^{120}{}_{}{}^{}\mathrm{Te}$ and ${}_{}{}^{122}{}_{}{}^{}\mathrm{Te}$ isotopes, which were not measured by muonic x rays. A combined analysis of the muonic atom and optical isotope shift data yielded high-precision values of the differences in radii Δ$R_k$,α (error <±0.5 am) and Δ〈$r^2$${〉}^{1/2}$ (error <±0.9 am) between the neighboring isotopes. The optical constants for the Te line λ=4049 Å were determined (including contributions of higher radial moments) to be F=(509±120) mK/${\mathrm{fm}}^2$ and M=-(104±63)×${10}^3$ mK. Systematic behavior of the radius differences in neighboring isotopes and isotones of Ba, Xe, Te, and Sn, together with odd-even staggering of the Te isotopes, are discussed in this paper. The ΔN=2 Te isotope shifts between even-A nuclei decrease nearly linearly with increasing N, which can be explained by a successive decreasing deformation in accordance with the observed systematics. The experimental data for the Te isotopes proved to be in good agreement with even-A Hartree-Fock calculations and with recent Hartree-Fock calculations for odd-A nuclei in which three-body forces are considered. A linear decrease of the nuclear skin thickness with decreasing deformation was observed and is explained by a simple model.

Inclusive double charge exchange reaction is studied by using a model which combines a microscopic many-body calculation of reaction probabilities with a Monte Carlo simulation procedure. Comparison with present experimental results requires that the (π,2π) reaction be included and a proper evaluation of this latter reaction is also done. The combined results compare favorably with experiment, giving extra support to this model of the pion-nucleus interaction which was previously shown to provide a good description of all other inclusive reactions and elastic scattering.

The internal bremsstrahlung spectrum of ${}_{}{}^{35}{}_{}{}^{}\mathrm{S}$ has been measured in the range from 10 to 100 keV. The magnetic deflection method is adopted for preventing the production of external bremsstrahlung in the detector. The measured spectrum agrees well with the Knipp-Uhlenbeck-Bloch and the Coulomb-corrected Knipp-Uhlenbeck-Bloch theories only in the range from 10 to 50 keV, but agrees well with the Vinh-Mau theory in the entire range from 10 to 100 keV.

In this study the decay of ${}_{}{}^{149}{}_{}{}^{}\mathrm{Er}_{}^{\mathrm{g}+\mathrm{m}}{}_{}{}^{}$ by positron emission, electron capture, and β-delayed proton emission was investigated. Gamma rays associated with ${}_{}{}^{149}{}_{}{}^{}\mathrm{Er}_{}^{\mathrm{m}}{}_{}{}^{}$ decay were placed in a decay scheme on the basis of γγ and xγ coincidences and half-life. We assigned 120 γ rays deexciting 91 levels in ${}_{}{}^{149}{}_{}{}^{}\mathrm{Ho}$ to 8.9±0.2 s ${}_{}{}^{149}{}_{}{}^{}\mathrm{Er}_{}^{\mathrm{m}}{}_{}{}^{}$ decay. The π$s_{1/2}$ single-particle state in ${}_{}{}^{149}{}_{}{}^{}\mathrm{Ho}$ was observed to occur at 49.0 keV above the π$h_{11/2}$ ground state. A (3.5±0.7) % isomeric transition decay branch and a (0.18±0.07) % β-delayed proton decay branch were determined for ${}_{}{}^{149}{}_{}{}^{}\mathrm{Er}_{}^{\mathrm{m}}{}_{}{}^{}$ decay. Three additional γ rays were assigned to 4±2 s ${}_{}{}^{149}{}_{}{}^{}\mathrm{Er}_{}^{\mathrm{g}}{}_{}{}^{}$ decay and a (7±2) % β-delayed proton decay branch was determined. Measured EC/${\beta }^{+}$ ratios to proton emitting states in ${}_{}{}^{149}{}_{}{}^{}\mathrm{Ho}$ resulted in a (${\mathit{Q}}_{\mathit{EC}}$-${\mathit{S}}_{\mathit{p}}$)=7.$0_{\mathrm{-}0.4}^{+5.0\mathrm{}}$ MeV for ${}_{}{}^{149}{}_{}{}^{}\mathrm{ER}_{}^8{}_{}{}^{}$ decay and a ${\mathit{S}}_{\mathit{p}}$=1.$4_{\mathrm{-}0.6}^{+10\mathrm{}}$ MeV for Ho. The β-delayed proton spectrum from ${}_{}{}^{149}{}_{}{}^{}\mathrm{Er}_{}^{\mathrm{g}}{}_{}{}^{}$ consisted of a highly structured component corresponding to the deexcitation of levels between 4 and 5 MeV in ${}_{}{}^{149}{}_{}{}^{}\mathrm{Ho}$ and a structureless component corresponding to decay from higher levels. The β-strength function for ${}_{}{}^{149}{}_{}{}^{}\mathrm{Er}_{}^{\mathrm{g}+\mathrm{m}}{}_{}{}^{}$ decay is discussed in terms of single-particle shell-model structure, weak coupling to the ${}_{}{}^{148}{}_{}{}^{}\mathrm{Dy}$ core, and decay of π$h_{11/2}$ protons across the shell closure to the ν$h_{9/2}$ neutron orbital.

We discuss boson transition densities within the interacting-boson-model picture in deformed nuclei. By using the concept of intrinsic state we determine simple expressions for the transition densities within the ground and to the lowest excited bands. Within this scheme we show that the choice of first and second derivatives of the equilibrium density for the functions ${\alpha }_2$(r) and ${\beta }_2$(r) associated with the transition operators $s^{\mathrm{°}}$d (or $d^{\mathrm{°}}$s) and $d^{\mathrm{°}}$d leads to boson inelastic transition densities within the ground band which are consistent with the description provided by the geometrical model, while deviations between the two models arise for the β and γ bands for characteristic values of the deformation parameters. As an illustration, inelastic quadrupole charge transition densities are analyzed in the case of deformed ${}_{}{}^{154}{}_{}{}^{}\mathrm{Gd}$.

In a recent work we have shown how the reaction matrices of the relativistic-Brueckner-Hartree-Fock theory can be well approximated in a simple model. In that model we could reproduce various matrix elements of the relativistic-Brueckner-Hartree-Fock reaction matrices in the Born approximation, if we added a number of pseudoparticles to the ‘‘mesons’’ used to construct one-boson-exchange models of the nuclear force. Here we present nuclear matter saturation curves, obtained using our pseudoparticle method, for two one-boson-exchange potentials. Our simple model reproduces the saturation curves calculated with the full relativistic-Brueckner-Hartree-Fock theory quite well. Within the context of the pseudoparticle approximation to the full relativistic-Brueckner-Hartree-Fock theory, one obtains reasonable values for the incompressibility parameter. (These values are quite similar to those obtained earlier using the full relativistic-Brueckner-Hartree-Fock analysis.)

The ${}_{}{}^{127}{}_{}{}^{}\mathrm{I}$${(}^3$He,t${)}^{127}$Xe reaction has been measured for low-lying states in ${}_{}{}^{127}{}_{}{}^{}\mathrm{Xe}$ which may play a role in neutrino capture by ${}_{}{}^{127}{}_{}{}^{}\mathrm{I}$. High-spin states at excitation energies $E_x$=309 and 646 keV are found to be much more strongly populated than the $J^{\pi }$=((3/2-${\mathrm{}(7/2)\mathrm{}}^{+}$ states relevant to neutrino capture by ${}_{}{}^{127}{}_{}{}^{}\mathrm{I}$.

Prompt and delayed γ-ray spectroscopy of reaction products selected in a recoil mass spectrometer was used to study both feeding and decay patterns of two successive isomeric decays in ${}_{}{}^{81}{}_{}{}^{}\mathrm{Sr}$ as proposed by Arnell and co-workers. Their assignment was confirmed. The measured lifetimes ($T_{1/2}$) are 0.44±0.10 μs and 6.4±0.5 μs for the 79 keV (${(5/2\mathrm{}}^{\mathrm{-}}$) and 89 keV (${(7/2\mathrm{}}^{+}$) levels, respectively. The former is in excellent agreement with the adopted value of 0.40±0.06 μs.

Photoparticle spectra from the ${}_{}{}^{12}{}_{}{}^{}(\gamma$,$p_i$) and ${}_{}{}^{12}{}_{}{}^{}(\gamma$,${\alpha }_0$) reactions have been measured in an angular aperture (FWHM) of 60° centered around 90°, using 28 MeV quasimonochromatic photons from annihilation-in-flight of positrons. The branching ratio for the (γ,${\alpha }_0$) to (γ,$p_0$) transition amounts to (2.9±1.2)%, while the (γ,$p_i$) branching to excited states in ${}_{}{}^{11}{}_{}{}^{}\mathrm{B}$ contributes (24±2)% to the observed (γ,p) cross section.

Sources of ${}_{}{}^{235}{}_{}{}^{}\mathrm{Th}$ were prepared by 14-MeV neutron irradiation of uranium followed by radiochemical separation. The β and γ spectra were measured with a semiconductor telescope and a HpGe detector, respectively. A β-decay end point energy of 1.44±0.05 MeV and a $Q_{\beta }$ value of 1.47+0.08 MeV for ${}_{}{}^{235}{}_{}{}^{}\mathrm{Th}$ were determined.

The method, previously used to obtain the nucleon momentum distribution in ${}_{}{}^2{}_{}{}^{}\mathrm{H}$ from the y-scaling analysis of inclusive electron scattering data, is extended to ${}_{}{}^3{}_{}{}^{}\mathrm{He}$. It is shown that the binding correction which has to be handled in this case does not hinder the extraction of the momentum distribution from the scaling function. The obtained momentum distribution satisfactorily agrees with the one extracted from exclusive (e,e’p) reactions.