Projectile breakup processes are probed by studying the emission of α particles in coincidence with projectile-like fragments as a function of the dissipated energy in the collisions of 35 MeV/nucleon ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ with ${}_{}{}^{58}{}_{}{}^{}\mathrm{Ni}$. Energy correlations between α particles and projectile-like fragments at small-angle geometries allow the separation of the sources of α emission from projectile-like and target-like fragments. We find that the slope parameters of the decay energy distributions, the average excitation energies, and the α particle multiplicities of the projectile-like fragments increase with increasing dissipation of energy. If the linear dependence, exhibited by the data, of the slope parameter with the dissipated energy is included in model calculations, the majority of the coincidence yield in the forward hemisphere can be explained. However, an excess yield of the data on the opposite side of the beam from the observed projectile-like fragment still remains. Such analysis of the data suggests that the breakup of the projectile is the dominant source of light particles at forward angles. Processes resulting in the breakup of the projectile must be better understood in order to study other processes leading to similar phenomena.

A framework is developed for the quantitative analysis of the electromagnetic dissociation of relativistic nuclei. This includes treatment of multiple excitations of the giant dipole resonance, coupled with calculations of the fragmentation probabilities in the framework of the statistical model. Experimental data on electromagnetic projectile dissociation at relativistic energies are compared to the model predictions and shown to be consistent with first-order excitation followed by statistical decay of the excited nucleus. Strategies for the search for multiple excitation processes and subsequent rare decay modes are discussed.

The ${}_{}{}^{32}{}_{}{}^{}\mathrm{S}$${+}^{12}$C and ${}_{}{}^{32}{}_{}{}^{}\mathrm{S}$${+}^{13}$C fusion cross sections have been measured in the energy range ${\mathit{E}}_{\mathrm{c}.\mathrm{m}.\mathrm{}}$=13.6 to 20 MeV. The comparison of both sets of measurements provides information on the influence of the inelastic and transfer channels on fusion. Our results indicate that both systems exhibit similar behavior in spite of the large positive Q value for the one-neutron-transfer channel in the ${}_{}{}^{32}{}_{}{}^{}\mathrm{S}$${+}^{13}$C case compared to the less favorable ${}_{}{}^{32}{}_{}{}^{}\mathrm{S}$${+}^{12}$C case. A small enhancement of the fusion cross sections relative to the predictions of an uncoupled barrier penetration model could be easily accounted for by including the effect of coupling to low-lying excited states of the participant nuclei.

High-spin states in ${}_{}{}^{74}{}_{}{}^{}\mathrm{Kr}$ were studied using the ${}_{}{}^{58}{}_{}{}^{}\mathrm{Ni}$${(}^{19}$F,p2n${)}^{74}$Kr reaction at 62 MeV. States up to (${14}^{+}$) in the ground state band and a number of states in three side bands were placed in the level scheme. The level scheme of ${}_{}{}^{74}{}_{}{}^{}\mathrm{Kr}$ closely resembles those of ${}_{}{}^{76}{}_{}{}^{}\mathrm{Kr}$ and ${}_{}{}^{78}{}_{}{}^{}\mathrm{Kr}$. Quasiparticle alignment occurs at ħω≊0.65 MeV in agreement with a recent calculation. There is no evidence for an alignment at lower frequency as was previously reported. Mean lifetimes were measured for six states in the ground state band of ${}_{}{}^{74}{}_{}{}^{}\mathrm{Kr}$ using the Doppler shift attenuation and recoil-distance methods. The lifetimes imply transition quadrupole moments of 3.2-3.3 eb, the highest known among Kr isotopes. The corresponding axial deformation is ${\mathrm{\beta }}_2$≊0.41.

We have performed detailed particle-γ and particle-γ-γ angular correlation measurements for two strong resonances observed in the elastic and inelastic scattering of ${}_{}{}^{24}{}_{}{}^{}\mathrm{Mg}$${+}^{24}$Mg. These data provide us with spectroscopic information relatively uncontaminated by nonresonant amplitudes, and allow spin assignments of ${\mathit{J}}^{\mathrm{\pi }}$=${36}^{+}$ for two resonances at ${\mathit{E}}_{\mathrm{c}.\mathrm{m}.\mathrm{}}$=45.70 and 46.65 MeV. The angular correlation data for the mutual $2^{+}$ inelastic scattering channel suggest a dominant decay l value of l=34 for both resonances. Correlated spin alignment data for this channel confirm our expectations for the relationship between angular momentum coupling and spin alignment for these resonances. The relatively high spin values suggest a resonance configuration in which the two ${}_{}{}^{24}{}_{}{}^{}\mathrm{Mg}$ nuclei interact pole-to-pole, allowing the system to sustain a large amount of angular momentum. The pole-to-pole grazing picture is supported by the results of model calculations of the ${}_{}{}^{24}{}_{}{}^{}\mathrm{Mg}$${+}^{24}$Mg${\to }^{48}$Cr system.

High-spin states in ${}_{}{}^{122}{}_{}{}^{}\mathrm{Cs}$ have been studied via the ${}_{}{}^{112}{}_{}{}^{}\mathrm{Sn}$${(}^{12}$C,pn) reaction. Two ΔI=1 band structures, along with E2 crossover transitions, are observed. One band is believed to be based on the π${\mathit{h}}_{11/2}$⊗ν${\mathit{g}}_{7/2}$ configuration. A band crossing is observed at a rotational frequency of ħ${\mathrm{\omega }}_{\mathit{c}}$=0.46 MeV which is expected from the alignment of an ${\mathit{h}}_{11/2}$ neutron pair. The second band, believed to be based on the π${\mathit{g}}_{7/2}$⊗ν${\mathit{h}}_{11/2}$ configuration, is observed up to high spin. The two signatures of this negative parity band show a small signature splitting as well as a common upbend. Calculations with both the cranked shell model (CSM) and a geometrical model are utilized to define the configurations and quasiparticles corresponding to the band crossings in this nucleus.

The ${(}^{20}$Ne${,}^{19}$Ne), ${(}^{20}$Ne${,}^{21}$Ne), and ${(}^{20}$Ne${,}^{21}$Na) reactions on ${}_{}{}^{90}{}_{}{}^{}\mathrm{Zr}$ and ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ have been investigated at 500 and 600 MeV incident energies. Experimental spectra have been compared with predictions of distorted-wave Born approximation calculations. The different shapes observed for proton and neutron pickup spectra are explained quite well by the calculations. In particular, the broad peak observed at about 6.5 MeV in the ${(}^{20}$Ne${,}^{21}$Ne) spectra is shown to originate from ejectile excitation in the 1${\mathit{d}}_{3/2}$, 1${\mathit{f}}_{7/2}$, and 2${\mathit{p}}_{3/2}$ orbitals. An important component of the ${(}^{20}$Ne${,}^{19}$Ne) cross section is due to three-body processes, such as the elastic breakup of ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$ into ${}_{}{}^{19}{}_{}{}^{}\mathrm{Ne}$ and one neutron. In addition, bumps are observed at about 1.5 and 10 MeV excitation energy in ${}_{}{}^{209}{}_{}{}^{}\mathrm{Pb}$ and 2.5 and 14 MeV in ${}_{}{}^{91}{}_{}{}^{}\mathrm{Zr}$. The low energy peaks are shown to originate mainly from neutron transfer to high spin orbitals, i.e., 1${\mathit{i}}_{11/2}$ and 1${\mathit{j}}_{15/2}$ in ${}_{}{}^{209}{}_{}{}^{}\mathrm{Pb}$ and 1${\mathit{g}}_{7/2}$ and 1${\mathit{h}}_{11/2}$ in ${}_{}{}^{91}{}_{}{}^{}\mathrm{Zr}$. Because of the selectivity of the ${(}^{20}$Ne, ${}_{}{}^{19}{}_{}{}^{}\mathrm{Ne}$) reaction for large angular momentum transfer, it is proposed that the structures observed at 14 MeV in ${}_{}{}^{91}{}_{}{}^{}\mathrm{Zr}$ and 10 MeV ${}_{}{}^{209}{}_{}{}^{}\mathrm{Pb}$ are due to a neutron transfer to high spin orbitals, such as 1${\mathit{i}}_{13/2}$ and 1${\mathit{k}}_{17/2}$ in ${}_{}{}^{91}{}_{}{}^{}\mathrm{Zr}$ and ${}_{}{}^{209}{}_{}{}^{}\mathrm{Pb}$, respectively.

The ${(}^6$Li${,}^6$He) reaction was studied on the target nuclei ${}_{}{}^{48}{}_{}{}^{}\mathrm{Ca}$ and ${}_{}{}^{90}{}_{}{}^{}\mathrm{Zr}$ at ${\mathit{E}}_{\mathrm{Li}}$=156 MeV at extreme forward reaction angles. From the zero degree spectra Gamow-Teller strength was extracted for excitation energies 0≤${\mathit{E}}_{\mathit{x}}$≲20 MeV. The results are compared with distorted-wave Born approximation calculations and (p,n) data.

The macroscopic model of nuclear shape evolutions describing nuclear coalescence and reseparation in heavy-ion collisions is applied to the sub-barrier region. The model brings out the important role of neck formation on sub-barrier fusion in addition to effects arising from collective excitations of the colliding partners and nucleons transfer in the entrance channel.

Revised NN elastic phase shifts are presented, with particular attention to isospin zero, and with extensive comments on the absolute normalization of np polarizations. The incentive for this revision is that new np data on ${\mathit{D}}_{\mathit{T}}$/${\mathit{R}}_{\mathit{T}}$, ${\mathit{A}}_{\mathit{N}\mathit{N}}$, ${\mathit{A}}_{\mathit{N}\mathit{O}}$, and ${\mathit{A}}_{\mathit{O}\mathit{N}}$ improve markedly the determination of ɛ${\mathrm{¯}}_1$ from 210 to 515 MeV. At these energies, phase shifts are accurately determined, despite a strong correlation between ${}_{}{}^1{}_{}{}^{}$${\mathit{P}}_1$ and ${}_{}{}^3{}_{}{}^{}$${\mathit{G}}_4$; a very precise measurement of either ${\mathit{A}}_{\mathit{L}\mathit{L}}$ or ${\mathit{K}}_{\mathit{L}\mathit{L}}$ could eliminate this problem. More extensive uncertainties in I=0 phase shifts at 800 MeV are discussed.

The locations of the dynamic poles in the complex energy plane of the s-wave T matrix for the coupled (K¯N,Σπ) system are calculated. Investigated are a quark bag model and several potential models, including one that agrees with the strong interaction shift in kaonic hydrogen as well as scattering data. Each potential model is found to support either one or no poles, while the bag model is found to support two. The poles energies are found to be quite different from the energy of the ${\mathrm{\Lambda }}^{\mathrm{*}}$(1405) determined by phenomenological analyses along the real energy axis.

Antinucleon-nucleus elastic scattering is addressed from the point of view of the off-shell properties of the two-body p¯-nucleon system. The energy dependence of the interaction is studied. Comparison with p¯${\mathrm{-}}^{12}$C elastic-scattering data at 50 MeV is satisfactory but shows very little sensitivity to the underlying potential. Scattering data at lower projectile energies should improve the situation.

A measurement of the analyzing power for n-p scattering has been made at center-of-mass angles, 8.8°, 15.0°, and 20.7° with a nearly monoenergetic polarized neutron beam peaked at 790 MeV. These angles represent an acceptance from 5° to 30° in the center of mass, and therefore extend to the smallest angles yet reached for measurement of this observable. The data are compared with the predictions of several phase shift analyses, and with the results from previous measurements that extend to larger angles for both free and quasifree n-p scattering.

We present global Dirac optical model fits to elastic proton scattering data from heavy nuclear targets at energies between 65 and 1040 MeV. Such optical potentials provide critical input for a wide variety of nuclear reactions. The energy and mass number dependence of the parameters in the Lorentz four-vector and scalar potentials of Dirac phenomenology are given. The characteristic features of the potentials are discussed and the predictive power of the global approach presented here is tested for both interpolation and extrapolation.

Convolution formulas for the inelastic structure functions of a nucleus are derived using the ‘‘instant’’ form of relativistic particle dynamics, and are contrasted with other convolution approaches. Using only physical nucleon constituents and harmonic oscillator shell model wave functions, the magnitude of the dip in the European Muon Collaboration ratio in the intermediate range of x is reproduced. The calculations of this ratio fail to come back up towards unity as x decreases below 0.4, and possible reasons for this are discussed.

Charge-symmetry breaking operators induced by quantum chromodynamical corrections to one-photon-exchange and one-photon loop graphs have been recently shown to contribute to isomultiplet splittings in the hadron spectrum at a level comparable to that of one-photon-exchange operators. We investigate the consequences of the existence of such (color-dependent) operators for charge-symmetry breaking in the ${}_{}{}^3{}_{}{}^{}\mathrm{-}_{}^3{}_{}{}^{}$H and ${}_{\mathrm{\Lambda }}{}^4{}_{}{}^{}\mathrm{-}_{\mathrm{\Lambda }}^4{}_{}{}^{}$H systems and demonstrate that sizable contributions to the charge-symmetry-breaking binding-energy differences are expected, especially in the former system.

Results are presented for the charge-symmetry superratio R, simple ratios ${\mathit{r}}_1$ and ${\mathit{r}}_2$, and the differential cross sections of ${\mathrm{\pi }}^{+}$ and ${\mathrm{\pi }}^{\mathrm{-}}$ elastic scattering on ${}_{}{}^3{}_{}{}^{}\mathrm{H}$ and ${}_{}{}^3{}_{}{}^{}\mathrm{He}$: R=${\mathit{r}}_1$${\mathit{r}}_2$, ${\mathit{r}}_1$=σ(θ)[${\mathrm{\pi }}^{+}$ ${}_{}{}^3{}_{}{}^{}\mathrm{\pi }_{}^{+}{}_{}{}^{}$ ${}_{}{}^3{}_{}{}^{}]$/σ(θ)[${\mathrm{\pi }}^{\mathrm{-}}$ ${}_{}{}^3{}_{}{}^{}\mathrm{\pi }_{}^{\mathrm{-}}{}_{}{}^{}$ ${}_{}{}^3{}_{}{}^{}]$, and ${\mathit{r}}_2$=σ(θ)[${\mathrm{\pi }}^{\mathrm{-}}$ ${}_{}{}^3{}_{}{}^{}\mathrm{\pi }_{}^{\mathrm{-}}{}_{}{}^{}$ ${}_{}{}^3{}_{}{}^{}]$/σ(θ)[${\mathrm{\pi }}^{+}$ ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ →${\mathrm{\pi }}^{+}$ ${}_{}{}^3{}_{}{}^{}]$. The measurements were made at ${\mathit{T}}_{\mathrm{\pi }}$=180 MeV and ${\mathrm{\theta }}_{\mathrm{\pi }}$(lab)=40°–90°; some data were obtained at ${\mathit{T}}_{\mathrm{\pi }}$=143 MeV also. At all angles, R>1 and ${\mathit{r}}_2$>1 indicative of a violation of charge symmetry; however, we also find that ${\mathit{r}}_1$≃1. Our data are consistent with ${\mathit{F}}_{\mathit{p}}$${(}^3$H)≃${\mathit{F}}_{\mathit{n}}$${(}^3$He) and ${\mathit{F}}_{\mathit{n}}$${(}^3$H)>${\mathit{F}}_{\mathit{p}}$${(}^3$He), where ${\mathit{F}}_{\mathit{p}}$ and ${\mathit{F}}_{\mathit{n}}$ are the proton and neutron matter form factors. σ(θ)[${\mathrm{\pi }}^{\pm }$ ${}_{}{}^3{}_{}{}^{}\mathrm{\pi }_{}^{\pm }{}_{}{}^{}$ ${}_{}{}^3{}_{}{}^{}]$ decreases with increasing magnitude of the four-momentum transfer t up to ${\mathrm{\theta }}_{\mathrm{c}.\mathrm{m}.\mathrm{}}$≃70°; the t dependence of the F ’s is comparable to that of the electromagnetic form factors. σ(θ)[${\mathrm{\pi }}^{\mathrm{-}}$ ${}_{}{}^3{}_{}{}^{}\mathrm{\pi }_{}^{\mathrm{-}3}{}_{}{}^{}$H] has a non-spin-flip dip at ${\mathrm{\theta }}_{\mathrm{c}.\mathrm{m}.\mathrm{}}$≃78°.

Relativistic ${\mathit{P}}_{11}$ wave functions are constructed that have 2S and 1S character in the static limit. Their constraint-free electromagnetic N-${\mathit{N}}^{\mathrm{*}}$ transition form factors are calculated from a conserved current. A gauge condition at ${\mathit{q}}^2$=0 is met by a three-quark current. The 2S helicity amplitudes are too large compared with the sparse data, while the 1S results are an order too low. A mixture of the 1S and 2S states agrees with the electroproduction but misses the photon point.

The separable potential equations that describe the hypertriton when ΛN-ΣN coupling and noncentral NN and YN forces are included, are formulated. Numerical solution of the equations for various potential models shows that Λ-Σ conversion in the YN interaction plays a significant role, even in the lightly bound ${}_{\mathrm{\Lambda }}{}^3{}_{}{}^{}\mathrm{H}$. When the ΣN channel is formally eliminated, the dispersive energy dependence of the resulting ΛN effective interaction is repulsive, whereas the resulting ΛNN three-body force is attractive. The contribution of the ΛN tensor force is shown to depend upon the inclusion of the NN tensor force and the relative sign of the ${}_{}{}^3{}_{}{}^{}$${\mathit{S}}_1$${\mathrm{-}}^3$${\mathit{D}}_1$ NN and ΛN tensor coupling. Also, a model which supports a ΣN bound state in the continuum appears to severely overbind the ${}_{\mathrm{\Lambda }}{}^3{}_{}{}^{}\mathrm{H}$ system, indicating that such a phenomenon is not present in the ${\mathit{K}}^{\mathrm{-}}$d→ΛNπ reaction.

Differential cross sections for the elastic scattering of 30 and 50 MeV ${\mathrm{\pi }}^{\mathrm{-}}$ by nuclei ranging from ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ to ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ have been measured using a range spectrometer. Comparison is made with the predictions of a recent optical-model calculation and the general nature of discrepancies is discussed.