We present the results of a phenomenological analysis of all existing data on pion single- and double-charge-exchange scattering to isobaric analog states at $T_{\pi }\simeq 164$ MeV. We use a theory in which both reactions are described by the same optical potential, $U$. The form of $U$ is theoretically motivated and separates explicitly the effects of nuclear structure and reaction dynamics. The latter is characterized phenomenologically by two complex numbers, one for the isovector and one for the isotensor term in $U$. Elastic scattering from selected $N=Z$ nuclei is independently fitted to determine the isoscalar terms in $U$. Realistic Skyrme III densities are used to describe the nuclear structure. We find one set of parameters which describes the scattering throughout the periodic table. The striking $N$, $Z$, and $A$ dependence predicted by the lowest-order $U$ and observed in the data is preserved.

Differential cross sections for ${\pi }^{+}\mathrm{d}$ and ${\pi }^{-}\mathrm{d}$ elastic scattering have been measured and compared at 256 MeV in order to provide a sensitive test of charge symmetry in nuclear interactions. New methods for calculating external and internal Coulomb corrections are presented and compared with data at 143 and 256 MeV. Sensitivities to mass and width differences among the components of the $\Delta$ resonance are determined. Accurate absolute ${\pi }^{-}\mathrm{d}$ cross sections were measured for the first time at 256 MeV; the ${\pi }^{+}\mathrm{d}$ differential cross sections agree well with other measurements.

We develop a method for finding resonance poles in Faddeev equations. The method is computationally simpler than previous methods and is based on the rotation of contour technique. It is applied to $\pi \mathrm{d}$ elastic scattering with coupling to the $\mathrm{N}\Delta$ channel. The position of the pole is compared with predictions based on Argand diagram and speed analysis. We find that the conventional methods are unreliable if the pole is further from the real axis than the $\Delta$ resonance pole.

Low temperature nuclear orientation of ${}_{}{}^{106}{}_{}{}^{}\mathrm{Ag}_{}^m{}_{}{}^{}$ and ${}_{}{}^{110}{}_{}{}^{}\mathrm{Ag}_{}^m{}_{}{}^{}$ in Zn and Fe and level mixing resonances on ${}_{}{}^{109}{}_{}{}^{}\mathrm{Ag}_{}^m{}_{}{}^{}$ have been measured in order to deduce $Q$ and $V_{\mathrm{zz}}$ values. A fourth-order resonance in ${}_{}{}^{109}{}_{}{}^{}\mathrm{Ag}_{}^m{}_{}{}^{}\mathrm{Zn}$ has been found with a full width at half maximum of 1.9 × ${10}^{-9\mathrm{}}$ eV, and $\frac{V_{\mathrm{zz}}\left(\mathrm{Ag}Cd\right)}{V_{\mathrm{zz}}\left(\mathrm{Ag}Zn\right)}=1.0064\mathrm{}\left(34\right)\mathrm{}$ was deduced. The electric quadrupole moments found in the literature, reevaluated for Sternheimer correction $Q\left({}_{}{}^{108}{}_{}{}^{}\mathrm{Ag}_{}^m{}_{}{}^{}\right)=+1.32\mathrm{}\left(7\right)\mathrm{}$ b and $Q\left({}_{}{}^{110}{}_{}{}^{}\mathrm{Ag}_{}^m{}_{}{}^{}\right)=+1.44\mathrm{}\left(10\right)\mathrm{}$ b, are used for the calibration of $V_{\mathrm{zz}}$ and yield $Q\left({}_{}{}^{106}{}_{}{}^{}\mathrm{Ag}_{}^m{}_{}{}^{}\right)=+1.11\mathrm{}\left(11\right)\mathrm{}$ b, $Q\left({}_{}{}^{109}{}_{}{}^{}\mathrm{Ag}_{}^m{}_{}{}^{}\right)=(+)0.97\left(11\right)\mathrm{}$ b, and $V_{\mathrm{zz}}\left(\mathrm{Ag}Zn\right)=+4.2\mathrm{}\left(5\right)\mathrm{}\times {10}^{17}$ V/${\mathrm{cm}}^2$. Furthermore, $\mu \left({}_{}{}^{106}{}_{}{}^{}\mathrm{Ag}_{}^m{}_{}{}^{}\right)=(+)3.82\left(8\right)\mathrm{}{\mu }_N$ and several $\delta \left(\frac{E2}{M1}\right)$ mixing ratios in ${}_{}{}^{106}{}_{}{}^{}\mathrm{Pd}$ are also determined. The quadrupole moments are in good agreement with Yukawa-plus-exponential macroscopic model and folded-Yukawa microscopic model calculations. The particle states can be described in terms of deformed Nilsson orbitals or three valence-proton holes coupled to a quadrupole vibrator.

The probability per $K$ capture for double $K$-shell ionization in the electron capture decay of ${}_{}{}^{54}{}_{}{}^{}\mathrm{Mn}$ was studied by recording coincidences between Cr $K$ x rays when the two $K$-shell vacancies were filled. The probability for this decay was found to be (3.6± 0.3)× ${10}^{-4\mathrm{}}$, which is a factor of 1.5 times the theoretical prediction by Suzuki and Law, and 3.2 times that of Intemann. The energy shifts of the $\mathrm{Cr} K{\alpha }^H$ and $\mathrm{Cr} K{\beta }^H$ hypersatellites were found to be 254±18 and 319±22 eV, respectively, which are about 5% higher than the calculation of Chen, Crasemann, and Mark.

It is observed that unlike the versions which rely on auxiliary potentials designed to cancel diagrams exactly, the continuous version of the Brueckner-Bethe-Goldstone theory can be used to calculate the properties and in particular the ground state energy of repulsive many body systems. The only proviso amounts to a trivial requirement on the effective mass at the Fermi momentum. These results are related to those concerning the predictions of the corresponding versions of Green's function theory for the analytical properties of the mass operator. The case of attractive many body systems is also considered.

In considering spherically symmetric three-dimensional systems, inverse methods are applied to the nuclear bound-state problem. While retaining only the self-interactions of the (occupied) bound-state levels, an analytical solution is obtained for the potential. The simplest possible approximation to it corresponding to a single fictitious bound state is used to evaluate (root mean square) radii. Combining this formula with the well-known $A^{\frac{1}{3}}$ dependence of the nuclear radii, a new formula is obtained containing the collective binding energy effect and the one of the saturation of nuclear forces. For absolute and relative radii (of isotopes of Sn, Xe, Nd, Dy, Yb, Os, Hg, Pb, and Pu), the results compare favorably with experiment. In spite of the crude approximations made, this approach yields the typical curvature of the plot of the experimental relative radii as a function of the mass number. The extreme simplicity of the formula recommends its use for global discussions or predictions. Yet, for a correct description of the finer details it is necessary to account explicitly for shell effects and deformations.

The results of a schematic one-BCS-quasiparticle—plus—rotor band mixing calculation, carried out for the $i_{\frac{13}{2}}$ neutron orbital at all deformations and all locations of the Fermi energy, have been used to bring out many new features, which are also supported by the experimental data. It is thus observed that decoupled bands of a generalized nature exist almost everywhere. For the Fermi energy lying in the lower half of the $j$ shell, it is found that a particle with an effective angular momentum $j^{\prime }<j$ is decoupled from the core and gives rise to decoupled bands having band head spin $I=j^{\prime }$. The value of $j^{\prime }$ decreases as the Fermi level rises. However, the nature of the results changes dramatically if the Fermi energy is raised beyond the $K=\frac{5}{2}$ level. This produces new types of decoupled bands, wherein a particle with an effective aligned angular momentum $j^{\prime }$ seems to be decoupled from a core having rotational angular momentum $R=2, 4, or 6$. The systematics from the experimental data is in complete agreement with the results from the calculations. The ${}_{}{}^{173-179}{}_{}{}^{}\mathrm{W}$ isotopes, however, completely disobey the general trends and may be explained by assuming a very small deformation only.

We calculate the three-body potential in Skyrme's chiral symmetric model. Different geometrical configurations like triangles and chains are investigated; the results exhibit a rich structure of the three Skyrmion potential which is in qualitative agreement with calculations using realistic three-nucleon forces. The most significant signs of these three-body effects are a soft attraction for the equilateral triangle and overall repulsion for the chain configuration. Spin-isospin dependences are discussed qualitatively.

Starting from the $A$-nucleon Schrödinger equation, collective and single particle degrees are separated by a transformation. Pure collective and pure single particle states appear as special states of one complete orthogonal system of functions. The formulae of the conventional unified model are obtained, augmented by restrictions caused by constraints on the new single particle coordinates. Sum rules for the magnetic dipole and the electric quadrupole moments of mirror nuclei, which are consequences of these constraints, are presented.

The level structure of ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ over an 80 keV region has been studied with a resolution of several hundred eV by means of resonance absorption of the 9.2 MeV ground-state transition from the ${}_{}{}^{13}{}_{}{}^{}\mathrm{C}(\mathrm{p},\gamma )$ reaction at $E_{\mathrm{p}}=1.75\mathrm{}$ MeV. Six, possibly seven, sharp levels were found. The ratio of average spacing to average width, $\frac{D}{〈\Gamma 〉}$, is about seven. The total photon absorption cross section of these discrete levels accounts for essentially all of the average cross section found in this region in low-resolution ($\gamma$,n) measurements. Two levels overlap, and can be tentatively identified with the position of a possible $1^{+}$ level proposed on the basis of polarization at 90° found in ($\gamma$, ${\overrightarrow{\mathrm{n}}}_0$) in earlier measurements at Argonne National Laboratory. Since the chance of overlap is small, given the value of $\frac{D}{〈\Gamma 〉}$, there may be a considerable amount of non-$E1$ strength in the excitation region from 8 to 10 MeV which has not yet been found.

Cross sections for evaporation residue formation have been measured for the systems ${}_{}{}^{28,30}{}_{}{}^{}\mathrm{Si}$+${}_{}{}^{58,62,64}{}_{}{}^{}\mathrm{Ni}$ in the energy range from about 0.9 up to 1.2 times the conventional Coulomb barrier. The fusion cross sections cover more than four orders of magnitude from ∼30 μb to ∼500 mb, and show isotopic effects which are interpreted in the frame of the model involving coupling of the entrance channel with positive and negative $Q$-value reaction channels.

Energy averaged cross sections for the ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}({}_{}{}^{18}{}_{}{}^{}\mathrm{O},\alpha ){}_{}{}^{26}{}_{}{}^{}\mathrm{Mg}$ reaction were studied. Over 80 states between $E_x\left({}_{}{}^{26}{}_{}{}^{}\mathrm{Mg}\right)=5\mathrm{} \mathrm{and} 20$ MeV were observed for many bombarding energies in the range $E\left({}_{}{}^{18}{}_{}{}^{}\mathrm{O}\right)=46-50\mathrm{}$ MeV. Broad, noncorrelated structures observed in the excitation functions prevent the application of Hauser-Feshbach analysis for spin spectroscopy to this particular data set. By implication, our results cast doubt on the previously suggested backbend in the ${}_{}{}^{26}{}_{}{}^{}\mathrm{Mg}$ yrast sequence.

The dynamical aspects of the correlation between fragment mass (and charge) variance and the energy loss for the ${}_{}{}^{136}{}_{}{}^{}\mathrm{Xe}$+${}_{}{}^{209}{}_{}{}^{}\mathrm{Bi}$ system have been studied. A classical dynamical model has been used to obtain the instantaneous values of the relative kinetic energy. The one-body transport model is used to calculate the corresponding nucleon exchange rate.

It is discussed to what extent nonexponential decay or the so-called zenon effect may lead to a measurable slowing down of extremely rare decay processes as double beta decay or proton decay.

We present results of calculations of the properties of the giant dipole resonance in the transitional Nd and Sm nuclei performed within the framework of the interacting boson model.

We present results of distorted-wave Born approximation calculations of longitudinal contributions to 180° inelastic electron scattering, in the limit of zero electron mass and pure Coulomb distortion. A rough estimate of said contributions is given for the transitions $0^{+}$→$2^{+}$ in ${}_{}{}^{166}{}_{}{}^{}\mathrm{Er}$, and ${\frac{7}{2}}^{+}\to {\frac{9}{2}}^{+}$ and ${\frac{11}{2}}^{+}$ in ${}_{}{}^{181}{}_{}{}^{}\mathrm{Ta}$. Results are compared to plane-wave Born approximation calculations of transverse form factors.

Recently it has been proposed that contributions from inelastic processes can explain the experimental results for nuclear excitation by positron annihilation. We find that these calculations overestimate the cross section for the inelastic process by many orders of magnitude and the mechanism for the excitation process is still an open question.

The decay of ${}_{29}{}^{57}{}_{}{}^{}\mathrm{Cu}_{28}^{}{}_{}{}^{}$ produced with the ${}_{}{}^{58}{}_{}{}^{}\mathrm{Ni}$(p,2n) reaction was identified by a 1112-keV $\gamma$ ray occurring in its daughter nucleus ${}_{}{}^{57}{}_{}{}^{}\mathrm{Ni}$ and the half-life and ${\beta }^{+}$ end-point energy were measured to be 223±16 ms and 7720±130 keV, respectively, applying a technique of fast transportation of irradiated targets. The $log\mathrm{ft}$ value and Gamow-Teller matrix element of the ground-to-ground mirror transition of ${}_{29}{}^{57}{}_{}{}^{}\mathrm{Cu}_{28}^{}{}_{}{}^{}(T_z=-\frac{1}{2})\to {}_{28}{}^{57}{}_{}{}^{}\mathrm{Ni}_{29}^{}{}_{}{}^{}(T_z=\frac{1}{2})$ was deduced to be $logft=3.71\mathrm{}\pm 0.05$ and $〈\sigma \tau 〉=0.37\mathrm{}\pm 0.11$. The present results indicate a large reduction of $〈\sigma \tau 〉$ from the single particle value (1.291) although ${}_{}{}^{57}{}_{}{}^{}\mathrm{Cu}$ is a nucleus obtained by adding one proton to the ${}_{28}{}^{56}{}_{}{}^{}\mathrm{Ni}_{28}^{}{}_{}{}^{}$ core.

The total cross section for ${}_{}{}^7{}_{}{}^{}\mathrm{Li}(\alpha ,\mathrm{n}){}_{}{}^{10}{}_{}{}^{}\mathrm{B}$ has been measured from threshold to $E_{\alpha }=5.67\mathrm{}$ MeV, and inverted by detailed balance to find the ${}_{}{}^{10}{}_{}{}^{}\mathrm{B}(\mathrm{n},{\alpha }_0)$ cross section from $0<\mathrm{}{E}_{\mathrm{n}}\le 0.78$ MeV. Parameters of two resonances, at $E_{\mathrm{n}}=241\mathrm{} \mathrm{and} 493$ keV, are determined from the data.