A model is developed which accounts for the observed momentum shift of 10-50 MeV/c between experimental results and distorted wave impulse approximations. Kinematical effects of the binding energy and the Fermi momentum in reactions of the type $A(x,yz)B$ are considered to be responsible for the shift. Several examples are discussed.

Cross sections for elastic and inelastic pion scattering from ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ at 162 MeV at angles from 8° to 32° are presented. Standard static model distorted-wave impulse approximation calculations using realistic form factors show large disagreement with the forward angle data for elastic scattering and for exciting both the $2_1^{+}$ and $0_2^{+}$ states.

An analysis of the coupled $\mathrm{N}\pi -\mathrm{N}\pi \pi$ system is carried out using the Hamiltonian of the Chew-Low theory. This Hamiltonian describes the interaction of pions with a static nucleon through the virtual process $\mathrm{N}\rightleftarrows \mathrm{N}+\pi$. A set of three-particle equations is obtained whose solutions satisfy two-and three-particle unitarity, as well as the discontinuity relations for the production amplitudes ($\mathrm{N}+\pi \to \mathrm{N}+2\mathrm{}\pi$) in the subenergy variables, i.e., the energy of one of the final state pions. It is shown that in order to satisfy the subenergy discontinuity relation, it is necessary to include all four $P$-wave $\pi$-N amplitudes as input to the three-particle equations. In particular, even though the $\Delta$ is not an elementary particle in the model considered, its amplitude must be part of the input. The analysis presented shows how to modify the standard three-particle equations to account for single nucleon intermediate states. An expansion for the production amplitude similar to the isobar expansion emerges from the analysis. An approximation for the nucleon propagator is obtained which includes the effect of two meson states.

The magnetic hyperfine splitting frequencies ${\nu }_m=\left|g{\mu }_{\mathrm{N}}\frac{B_{\mathrm{HF}}}{h}\right|$ of ${}_{}{}^{106}{}_{}{}^{}\mathrm{Ag}_{}^m{}_{}{}^{}(I^{\pi }=6^{+}; T_{\frac{1}{2}}=8.5\mathrm{} \mathrm{d})$ as a dilute impurity in Fe and Ni have been measured with nuclear magnetic resonance on oriented nuclei at temperatures of ∼10 mK as 210.57(3) MHz and 50.76(4) MHz, respectively. With the magnetic hyperfine field known from ${}_{}{}^{110}{}_{}{}^{}\mathrm{Ag}_{}^m{}_{}{}^{}\mathrm{Fe}$ to be $B_{\mathrm{HF}}\left(\mathrm{Ag}Fe\right)=-446.9\mathrm{}\left(5\right)\mathrm{}$ kG, the magnetic moment of ${}_{}{}^{106}{}_{}{}^{}\mathrm{Ag}_{}^m{}_{}{}^{}$ is derived as $\mathrm{}(+)3.709\left(4\right)\mathrm{} {\mu }_N$. The magnetic hyperfine field of Ag in Ni is deduced to be -107.7(2) kG, which is in contradiction to the value in the literature. From the differential resonance displacements of $\gamma$ transitions with different multipolarities, an upper limit for the electric quadrupole splitting of ${}_{}{}^{106}{}_{}{}^{}\mathrm{Ag}_{}^m{}_{}{}^{}\mathrm{Fe}$ is estimated. In addition, multipole mixing ratios for a series of transitions in ${}_{}{}^{106}{}_{}{}^{}\mathrm{Pd}$ were determined. The spin of the 2366 keV level of ${}_{}{}^{106}{}_{}{}^{}\mathrm{Pd}$ is determined to be $I=5\mathrm{}$.

Methods which include the effect of mean-field fluctuations on the nuclear partition function and level density of hot nuclei are tested by applying them to a many-body system for which exact solutions are available, the Lipkin model. It is found that for finite systems fluctuation corrections to the mean field partition function and level density can be substantial, and especially so near a shape phase transition where these fluctuations smooth out discontinuities in the mean-field quantities. The model calculations suggest that only time-independent fluctuations are important at high temperatures or at high excitation energies. Moreover, even when fluctuations are restricted to a small set of constraints, a significant improvement over the mean-field calculations can result. This is thus a practical approximation since it requires only knowledge of the deformation free energy surfaces at finite temperature.

The magnetic moment of the $4_1^{+}$ state in ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$ was measured by the transient field technique, and the transient field was calibrated in a simultaneous measurement on the $2_1^{+}$ state. The resulting $g\left(4_1^{+}\right)=0.49\mathrm{}\pm 0.34$ is in agreement with the shell model description of ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$. The magnitude of the transient field measured in previous experiments on O, Ne, and Mg ions traversing iron foils was reexamined and appears to be in good agreement with the results of this experiment.

The energies of the muonic $4f\to 3d$ and $3d\to 2p$ transitions have been measured in the even-$A$ lead isotopes, with several times the precision of any previous measurement. The isotope shifts and intradoublet energy differences are in excellent agreement with earlier work but the absolute energies generally differ by two or more standard deviations. The new results do not completely resolve the discrepancy between experimental and theoretical binding energies in muonic ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$.

Measurements have been made of the inelastic cross sections and analyzing powers between 2° and 9° for nine $2^{+}$ states in ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$ with excitation energies below 10.0 MeV excited by 334-MeV protons. The data can be well described by macroscopic distorted-wave Born approximation calculations. In general the $\beta R$ values deduced from the analysis are in agreement with those obtained by other means. We do not observe a $2^{+}$ state at 6.422 MeV recently reported in a study of the ($\gamma$,${\gamma }^{\prime }$) reaction. A peak at 9.868 MeV is observed which can be described by an $L=(0\mathrm{} or 1)+2$ admixture. For the $L=2\mathrm{}$ component (i.e., $2^{+}$ state), we deduce $B\left(E2\mathrm{}\right)\mathrm{}\downarrow =2.0\mathrm{}\pm 0.4 e^2$ ${\mathrm{fm}}^4$.

The $\beta$-delayed proton spectra of ${}_{}{}^{147}{}_{}{}^{}\mathrm{Dy}$ and the hitherto unknown isotope ${}_{}{}^{149}{}_{}{}^{}\mathrm{Er}$ were investigated in ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ bombardments of ${}_{}{}^{142}{}_{}{}^{}\mathrm{Nd}$ and ${}_{}{}^{144}{}_{}{}^{}\mathrm{Sm}$., respectively. The ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$+${}_{}{}^{142}{}_{}{}^{}\mathrm{Nd}$ data confirm preliminary results of Klepper et al. that the ${}_{}{}^{147}{}_{}{}^{}\mathrm{Dy}$ delayed-proton spectrum has a high-energy cutoff at ∼5 MeV and is dominated by distinct peaks below 4 MeV in excitation. The proton spectrum following ${}_{}{}^{149}{}_{}{}^{}\mathrm{Er}$ decay has a half-life of 9±1 sec and extends from about 2.0 to 6.5 MeV; it has less of the sharp structure observed for ${}_{}{}^{147}{}_{}{}^{}\mathrm{Dy}$. The difference probably arises from the expected lower level density in ${}_{}{}^{147}{}_{}{}^{}\mathrm{Tb}$, a nucleus with one proton outside the ${}_{}{}^{146}{}_{}{}^{}\mathrm{Gd}$ core.

A practical and flexible variational method is employed to calculate the trinucleon ground state energy, wave function, and charge form factor, using the $s$-wave Malfliet-Tjon potentials V and VI. The results are compared with existing accurate solutions of the same potentials. The charge form factor is found to be rather insensitive to the addition of different three-body forces.

Employing a recently advanced model for fragmentation of heavy targets in medium and high energy nucleus nucleus collisions, we analyze the apparent slopes of the energy distribution of medium mass fragments. In this model a fragment is emitted after it has absorbed a nucleon from a hot spot, which is formed during the initial state of the reaction. The calculated slopes, being a combination of the hot spot temperature and the Fermi momentum, reproduce the available data very well.

The predictions of the intranuclear cascade model for pion-nucleus reactions is reexamined in view of new experimental and theoretical developments that affect the understanding of the true pion absorption process. A strong suppression of pion absorption on $T=1\mathrm{}$ nucleon pairs causes only slight differences in the intranuclear cascade predictions since there is an isospin-dependent distance restriction in the model. We have also shown that the data that were interpreted as an indication for double-$\Delta$ excitation can be explained also by sequential delta formation prior to absorption.

The quantization of an extended time-dependent Hartree-Fock equation is performed by using the path integral formalism. The path integral form of time evolution operator between initial and final states is obtained with the use of the completeness relation of the fermion coherent states. It is shown that the extended time-dependent Hartree-Fock equation is naturally derived as a classical limit of the path integral.

The off-shell properties of a recently proposed $\Lambda -\alpha$ interaction is studied with particular emphasis on the action of the different regions of the potential in producing the on- and off-shell amplitudes. To that end we have made use of a combined variable phase off-shell scattering theory. It is found that the potential has desirable off-shell properties to be useful in hypernuclear few-body problems.

Green's function techniques are used to express the solution of a many-body system in terms of the solutions of any two of its subsystems.

It is shown that a solution to the difficulty encountered in reproducing simultaneously the experimental longitudinal and transverse response functions deduced from deep inelastic electron scattering may be found in a consistent treatment of the electromagnetic interaction in a Dirac equation in which Lorentz scalar and vector potentials are explicitly introduced. Results for ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ and ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$ are given and compared with experiments.

The importance of medium corrections in the excitation of the isovector giant monopole resonance by nucleons is investigated. A large reduction of the cross section, compared to calculations with free $t$ matrices, is found at projectile energies around 100 MeV. This will make observation of the isovector monopole at these energies even more difficult than estimated by Auerbach et al.

The role of medium corrections in isovector excitations induced by the (p,n) reaction near 120 MeV is examined in light of the preceding Comment by Bauhoff which addresses the issue of making reliable estimates of the sizes of (p,n) cross sections for exciting isovector monopole resonances. To establish confidence in such estimates it is important to examine in parallel the much better understood isobaric analog of the ground state and the relative importance of medium modifications on these monopole transitions. Our examination using both density-independent and density-dependent transition operators supports the assertion of Bauhoff.

Differential cross sections of (${}_{}{}^3{}_{}{}^{}\mathrm{He}$, ${\pi }^{\pm }$) exclusive reactions have been measured for ${}_{}{}^7{}_{}{}^{}\mathrm{Li}$ and ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ targets at 235 MeV and 20° laboratory scattering angle. Several levels of the final nuclei have been observed for ${\pi }^{+}$ as well as ${\pi }^{-}$ production. Simple assumptions for the reaction mechanism are considered for explaining the ratio of ${\pi }^{-}$ to ${\pi }^{+}$ production.