High resolution singles and coincidence measurements have been made on gamma rays from the decay of ${}_{}{}^{148}{}_{}{}^{}\mathrm{Eu}$. On the basis of extensive γ-γ coincidence data, several new placements for transitions have been found. In addition, new weak γ rays have been discovered. The present study has produced a revision of the previously proposed decay schemes for almost every level above the first four excited states. Previously reported levels at 1972, 2173, 2208, 2313, 2633, 2647, and 2752 keV have been discarded for lack of confirmatory evidence. New levels are proposed at 2128, 2532, 2584, 2702, and 2727 keV. For levels at 1733, 1895, 2031, 2096, 2111, 2147, 2214, 2228, 2327, 2490, 2524, 2641, 2723, 2802, and 2831 keV, γ-γ angular correlation studies have been carried out on 22 cascades to confirm $J^{\pi }$ assignments and deduce mixing ratios of the transitions concerned. A complementary study of gamma rays and conversion electrons from the ${}_{}{}^{146}{}_{}{}^{}(\mathit{\alpha }$,2nγ) reaction at 26 MeV has been carried out. Singles, γ-γ coincidence, and γ-ray angular distribution measurements were made to provide information on high-spin states in the ${}_{}{}^{148}{}_{}{}^{}\mathrm{Sm}$ nucleus.

Inelastic scattering of 65-MeV protons on ${}_{}{}^{50}{}_{}{}^{}\mathrm{Ti}$, ${}_{}{}^{52}{}_{}{}^{}\mathrm{Cr}$, and ${}_{}{}^{54}{}_{}{}^{}\mathrm{Fe}$ has been measured for states of up to 11-MeV excitation energy. Clusters of $3^{\mathrm{-}}$ states in all three nuclei are found to form low-energy-octupole resonances at a mean energy of $E_x$∼7.5 MeV. The systematic decrease in excitation strength of the first $3^{\mathrm{-}}$ state with mass number has been observed. This decrease is interpreted in terms of the ‘‘blocking’’ effect on proton transitions from the sd shell orbits to the $f_{7/2}$ orbit. Many $1^{+}$ and possible $1^{+}$ states have been identified at $E_x$=5–10 MeV. In many cases, the $1^{+}$ assignments are in agreement with those of the previous works. A measurement of the ${}_{}{}^{49}{}_{}{}^{}\mathrm{Ti}$(d,p${)}^{50}$Ti reaction at 60 MeV has also been carried out to extract spectroscopic information on the fragmented $1^{+}$ states at around $E_x$=10 MeV in ${}_{}{}^{50}{}_{}{}^{}\mathrm{Ti}$. One-particle–one-hole proton admixtures in the wave functions of the $1^{+}$ states in ${}_{}{}^{50}{}_{}{}^{}\mathrm{Ti}$ are discussed.

The opaque Serber model is extended for ‘‘stripping’’ reaction in heavy ion projectile dissociation by incorporating a critical distance between constituent clusters in the projectile. This model describes the higher energy part of the fragment inclusive spectra. The results are discussed in comparison with the local-momentum plane-wave Born approximation calculations by McVoy and Nemes and with the Friedman model.

The ${}_{}{}^{12}{}_{}{}^{}$C${(\mathrm{}}^{10}$B,p${)}^{21}$Ne reaction has been investigated at an incident energy of 20 MeV. Complete angular distributions were measured in the angular range ${\theta }_{\mathrm{lab}=7.5\mathrm{}\mathrm{°}–161.25\mathrm{°}}$ using a multiangle spectrograph. Angular distributions for states in ${}_{}{}^{21}{}_{}{}^{}\mathrm{Ne}$ up to 6.75 MeV excitation are found to be symmetric around 90°. Results have been analyzed in terms of Hauser-Feshbach compound-nucleus calculations. A simple analysis of the angle-integrated cross sections versus (2J+1) shows that the (2J+1) rule holds for states with angular momenta up to (7/2). States with higher J are significantly enhanced due to kinematical conditions. The Hauser-Feshbach calculations account fairly well for the high-J enhancement of ${\sigma }_{\mathrm{tot}}$.

Complete angular distributions (${\theta }_{\mathrm{c}.\mathrm{m}.\mathrm{}}$=9°–90°) for the reaction ${}_{}{}^{13}{}_{}{}^{}\mathrm{C}$,α)${}^{22}$ Ne in the energy range $E_{\mathrm{c}.\mathrm{m}.\mathrm{}}$=6.25–13.38 MeV have been measured. The data exhibit significant resonancelike behavior and a portion of it has been fitted to extract the amplitudes and phases of the relevant l values with two methods. The first uses a least-squares procedure to fit the angular distributions to a linear sum of Legendre polynomials while the second makes a grid search to find a best fit to an amplitude squared equation.

Complete angular distributions (${\vartheta }_{\mathrm{c}.\mathrm{m}.\mathrm{}}$=9°–90°) for the reaction ${}_{}{}^{13}{}_{}{}^{}\mathrm{C}$,α)${}^{22}$ Ne in the energy range $E_{\mathrm{c}.\mathrm{m}.\mathrm{}}$=6.25–13.38 MeV have been subjected to a battery of tests to determine the existence of a significant nonstatistical component in the cross section. The autocorrelation function, distribution of cross sections, and channel correlations were investigated. The data were also compared with the predictions of Hauser-Feshbach calculations. A large nonstatistical component was found in all tests and comparisons.

Projection operator methods are used to obtain the elastic differential scattering cross section at 90° c.m. for ${}_{}{}^{28}{}_{}{}^{}$Si${+\mathrm{}}^{28}$Si in the region $E_{\mathrm{lab}=100\mathrm{}–}$120 MeV. Good agreement with the energies and structures of resonances seen experimentally is obtained by introducing doorway states for l=34–38 constructed from a particle-vibration model that includes both the $2^{+}$ and $3^{\mathrm{-}}$ excitation energies of ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$. The sudden approximation is used in deriving the ion-ion potential and the density distribution is investigated. The calculated cross sections and widths support the association of the resonances with nuclear molecular formation.

The population of excited states of Li and Be nuclei emitted in the ${}_{}{}^{14}{}_{}{}^{}$N+Ag reaction E/A=35 MeV has been measured. The results confirm a recently measured disagreement between the temperature determined from the slopes of the energy distributions and that obtained from the excited state populations. Recent models which were developed to explain the discrepancy are discussed.

Detailed angular distributions have been measured for ${}_{}{}^7{}_{}{}^{}\mathrm{Li}$ elastic and inelastic scattering to the first ${1/2}^{\mathrm{-}}$ state in ${}_{}{}^7{}_{}{}^{}\mathrm{Li}$ (projectile excitation) and the first $2^{+}$, $3^{\mathrm{-}}$, and $5^{\mathrm{-}}$ states in ${}_{}{}^{40}{}_{}{}^{}$Ca at E${(\mathrm{}}^7$Li)=34 MeV. Distorted-wave Born approximation and coupled-channels calculations of the inelastic processes were carried out with both Woods-Saxon and microscopic double-folded real optical potentials. No renormalization of the real double-folded potential is needed to fit the elastic data when the contribution from the ground state quadrupole moment of ${}_{}{}^7{}_{}{}^{}\mathrm{Li}$ is accounted for in coupled-channels calculations, otherwise a renormalization of 0.6 is required. Moreover, these coupled-channels calculations matched the phase of the oscillations in the projectile excitation data, while calculations employing a Woods-Saxon real potential did not. The calculations for the excitation of states in ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$ were insensitive to the form of real potential chosen.

The mechanisms of transfer and breakup in heavy-ion-induced reactions have been studied for the ${}_{}{}^{20}{}_{}{}^{}$Ne${+\mathrm{}}^{197}$Au system at bombarding energies of 220 and 341 MeV. A 4π detector was used to separate reactions leading to the production of projectilelike fragments into components having either two charged bodies in the final state (transfer) or three or more charged fragments (breakup). For both components, angular distributions, energy spectra, and production cross sections are shown for projectile fragments of Z=3–9. The ratio of transfer to inclusive yields initially drops steeply with decreasing ejectile charge, leveling off for Z≤7. The lower bounds on this ratio are ≃60% and ≃30% at 220 and 341 MeV, respectively. At 341 MeV, the trends in the central moments (mean, width, and skewness) of the ejectile energy spectra, as a function of Z, are similar for transfer and breakup. The primary ejectile yields are deduced from the breakup and transfer cross sections, and comparisons are made with the predictions of various models. The relatively large probabilities for primary ejectiles to be produced in charged-particle-bound states, observed for all Z and at both 220 and 341 MeV, indicate that, on average, most of the excitation energy resides in the heavy, targetlike fragment.

Excitation functions of the reaction ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$${(}^{12}$C,α${)\mathrm{}}^{20}$Ne have been measured in energy steps of 25 and 12.5 keV from $E_{\mathrm{c}.\mathrm{m}.\mathrm{}=5.7\mathrm{}}$ to 6.1 MeV at 18 angles between ${\theta }_{\mathrm{c}.\mathrm{m}.\mathrm{}=5\mathrm{}}$° and 90°. A recently published method for the determination of the true S-matrix elements of a reaction including only spinless particles was applied to the ${\alpha }_0$ exit channel. All quasimolecular resonances previously reported in the energy range studied were confirmed and spin assignments are made.

Exciton model calculations within the geometry-dependent hybrid model have been performed to study the proton-induced fission of ${}_{}{}^{232}{}_{}{}^{}\mathrm{Th}$ and Ir. After adjusting the parameters of the model to reproduce observed (p,xn) and total fission cross section, isotopic distributions of Rb and Cs have been evaluated and compared with experimental distributions measured by on-line mass spectrometry. With simplifying assumptions on the charge division mechanism, the experimental Cs distributions are very well reproduced in the ${}_{}{}^{232}{}_{}{}^{}\mathrm{Th}$(p,f) case. Observed structures are explained in terms of reaction mechanisms. The fission of medium-heavy elements [e.g., Ir(p,f)] appears to be promising for studying high excitation energy fission events and angular momentum effects.

The differential cross section has been measured for the elastic πd scattering reaction between 73° and 172° at 11 energies between 124 and 324 MeV. The data agree well in the regions of angular overlap with previous measurements in the forward hemisphere, but disagree with some earlier large angle measurements. In particular, within the statistical accuracy of our data, no significant structure is observed in the energy dependence of the large angle cross sections.

The influence of dispersive, medium effects on pion-nucleus elastic scattering is investigated in a simple model. The pion-nucleus interaction in the impulse approximation is represented by an optical potential whose form is motivated by field-theoretic considerations and the properties of the ${\Delta }_{33}$ resonance. The intermediate ${\Delta }_{33}$ spectrum is described by a mean spectral energy, $E_{\mathrm{ms}}$, where the shift $E_{\mathrm{ms}}$ represents the average of the ${\Delta }_{33}$-nucleus mean field, $U_{\Delta }$, over the nucleon and pion wave functions. We calculate the real part of $E_{\mathrm{ms}}$ as a function of mass number A and pion energy ω, assuming that $U_{\Delta }$ is numerically the same as the nucleon-nucleus shell-model potential. We compare our theory to more conventional ones, showing that the mean spectral energy is an important correction for pion-nucleus elastic scattering.

Spin observables for inelastic proton nucleus scattering are calculated in plane-wave impulse approximation both nonrelativistically and using the Dirac equation. The relativistic treatment yields nonzero spin difference functions that vanish in the nonrelativistic case. We identify the origin of this important contribution of the relativistic treatment, and stress its universal character. We treat 500 MeV proton scattering from ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ as an example.

We consider a simple model of the π-N scattering amplitude in nuclear matter, in which the intermediate pion propagators appearing in π-N diagrams are dressed through the scattering of the pion from the background nucleons. We use this model to calculate the differential cross section for the exclusive (π,πN) knockout reaction with the geometry of the experiment especially chosen to maximize the possibility of observing renormalization of the Δ resonance in the nuclear interior.

Quasifree p-p and p-d scattering from ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ at intermediate energies has been studied. The ${}_{}{}^3{}_{}{}^{}\mathrm{He}$(p,2p)d reaction has been measured at 300 MeV at the angle pair 70°-33° and at 450 MeV at the angle pairs 70°-30° and 46°-46° for recoil momenta between 350 and 530 MeV/c. For the ${}_{}{}^3{}_{}{}^{}\mathrm{He}$(p,pd)p reaction, energy sharing loci have been measured at 300 MeV at the angle pair 70°-33° and at 450 MeV for the angle pairs 25°-68°, 50°-68°, and 70°-30°, yielding a recoil momentum range from 0 to 480 MeV/c. The spectral function S(q,E) with E equal to the two-body breakup energy for ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ has been deduced from the present results in the framework of the plane-wave impulse approximation as a function of the p-d relative momentum q. The spectral function is compared with other spectral functions obtained from previous ${}_{}{}^3{}_{}{}^{}\mathrm{He}$(p,pd)p and ${}_{}{}^3{}_{}{}^{}\mathrm{He}$(e,e’p)d experiments and with existing theoretical predictions.

Doubly differential cross sections for producing ${\pi }^{+}$ and ${\pi }^{\mathrm{-}}$ were measured for several target-projectile combinations. They were ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ar}$+C, Ca, and U at 1050A MeV and ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$+Be and NaF at 655A MeV. The ${\pi }^{\mathrm{-}}$/${\pi }^{+}$ ratios are smaller than those expected from several Coulomb effect calculations. The Ne+NaF→${\pi }^{\mathrm{-}}$ data exhibit a peak at 90° in the center of mass and $p_{\pi }$=0.4$m_{\pi }$c.

We show that the experimental results for pion elastic scattering from the calcium isotopes in the ${\Delta }_{33}$ resonance region can be well represented at small angles in terms of the variables of diffraction theory. The parameters describing the amplitude reflect physics that can be attributed to pion and ${\Delta }_{33}$ dynamics in a microscopic approach, as well as to details of the neutron and proton densities. Using a phenomenological determination of the former, we show that the expermental results require a neutron skin in excess of that obtained from scaling the proton density according to the relative number of neutrons and protons. The experimental results are consistent with microscopic Hartree-Fock densities, provided that the ratio of isovector to isoscalar optical potential is substantially enhanced over the value obtained from the free pion-nucleon scattering amplitude. The size of this enhancement agrees with pion single-charge-exchange scattering from the calcium isotopes.

Angular distributions have been measured for ${\pi }^{\pm }$ elastic scattering at 50 MeV from ${}_{}{}^{14}{}_{}{}^{}\mathrm{C}$. Comparison with previously measured distributions for ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ shows a significant isotopic difference for ${\pi }^{\mathrm{-}}$ scattering. The data were analyzed using the second order Michigan State University optical potential proposed for low energy pion nucleus elastic scattering. Agreement with the data was obtained using the same density distributions for the protons and neutrons.