The ground state Q value of the reaction ${}_{}{}^{58}{}_{}{}^{}\mathrm{Ni}$${(}^7$Li, ${}_{}{}^8{}_{}{}^{}\mathrm{He}$${)}^{57}$Cu has been measured [Q=-29.564(50) MeV]. The cross section for this reaction was found to be 130(30) nb/sr at 5.0 deg in the laboratory. This is the first report of the use of the ${(}^7$Li${,}^8$He) reaction and the first measurement of the ${}_{}{}^{57}{}_{}{}^{}\mathrm{Cu}$ mass excess. The deduced ${}_{}{}^{57}{}_{}{}^{}\mathrm{Cu}$ atomic mass excess is -47.35(5) MeV. The implications of this result with respect to Coulomb displacement energy anomalies and nucleosynthesis of elements with A>56 by the rp process are discussed.

Differential cross sections for elastic and inelastic ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ scattering from ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ at $E_{\mathrm{c}.\mathrm{m}.\mathrm{}=16\mathrm{}}$ and 20 MeV, and scattering from ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ at 18.7 MeV were measured out to ${\theta }_{\mathrm{c}.\mathrm{m}.\mathrm{}\mathrm{\approxeq }170}$°. Also by scattering ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ and ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ from ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$, the inelastic cross sections for the excitation of the $3^{+}$ (2.18 MeV) and the $2^{+}$ (4.31 MeV) states of ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ and an estimate of the continuum inelastic cross sections of ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ were determined. The inelastic data were analyzed using the distorted-wave Born approximation and coupled-channels techniques with folded real and phenomenological imaginary form factors, with the deformations derived from electron scattering. The inelastic data are well described. Coupled-channels effects due to the $3^{+}$ state of ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ were found to play an important role in the scattering. The inclusion of the $3^{+}$ state in the coupled-channels calculations reduced the discrepancy in the normalization of the real double-folded potential between ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ and other heavy-ion projectiles, and the imaginary potential became weaker in the surface region. The present results show that L=2 coupling in the elastic scattering is very important and that the source can be a state in either the projectile, the target, or both.

The nuclear interactions of ${}_{{\mathrm{}}^1{\mathrm{}}_{79}^{97}}{}^{}{}_{}{}^{}\mathrm{Au}$ nuclei of initial energy 990 MeV/nucleon have been studied in nuclear emulsions as they slow down and stop. Typically, these interactions are fragmentations of the incident nucleus into an average of 2.0±0.3 fragments with Z≥3 and 4.2±0.2 helium nuclei. As many as eight Z≥3 fragments or 22 helium nuclei have been observed to be produced in a single interaction. The dependence on incident energy and target nucleus is discussed. Some 7% of the interactions appear to be fission in flight of the excited projectile nucleus emerging from the interaction, with the release of two highly charged fragments that contain most, if not all, of the incident charge. The charge distribution of these fragments ranges from symmetric to highly asymmetric.

Target fragment formation cross sections for nuclides with 24≤A≤237 have been measured for the interaction of 1.0, 3.0, 4.8, and 12.0 GeV ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ and 8.0 and 20.0 GeV ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$ with ${}_{}{}^{238}{}_{}{}^{}\mathrm{U}$. Fragment isobaric yields were deduced from these data. The light fragment (A<60) yields increase rapidly with increasing projectile energy until 4 to 8 GeV with only smaller increases in yield with increasing projectile energy beyond this consistent with the origin of these fragments in a high deposition energy process. The yields of n-rich fragments (80≤A≤145) are energy independent from 1–20 GeV consistent with their origin in low energy fission of a uranium-like species. The n-deficient fragments (80≤A≤145) have excitation functions consistent with their origin in either a deep spallation or high energy fission process. (At a ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ projectile energy of 1.0 GeV, the n-deficient fragments appear to originate primarily from a fission rather than a spallation process.) The excitation functions of the heavy fragments with 60≤A≤200 are similar to those of the light fragments. No large yields of these fragments were observed for any system studied, contrary to a previous report. Both the intranuclear cascade model and the nuclear firestreak model satisfactorily predict the observed yields of fragments with A>60, indicating that the general pattern of yields of these fragments is governed by the excitation energy deposited in the nucleus during the first step of the reaction and the geometry of the collision.

The effects on the forward glory enhancement of Δ${\sigma }_T$≡${\sigma }_R$- F [(d${\sigma }_{\mathrm{Ruth}}$/dΩ)-(dσ/dΩ)]dΩ, where ${\sigma }_R$ is the total reaction cross section, arising from the static deformation of the target in heavy-ion elastic scattering, are investigated. Within a sudden-limit calculation, it is found that the deformed nuclear field merely reduces the amplitude of the energy oscillation of Δ${\sigma }_T$, without inflicting noticeable change in the period. Calculation was performed for several light heavy-ion systems.

A general method is presented for determining an equilibrium point on a potential energy surface subject to an arbitrary number of constraints. The method is then specialized to the calculation of a conditional saddle point in the liquid-drop model for which the constraint is the mass-asymmetry degree of freedom. This approach is useful for cases in which the mass asymmetry is not one of the chosen coordinates but instead is a function of these coordinates. Conditional saddle points are calculated for the liquid-drop and Yukawa-plus-exponential nuclear energy models, with the nuclear shape parametrized using both a three-quadratic-surface model and a Legendre polynomial expansion of the nuclear surface function. We show how the conditional saddle-point shapes and energies change as the fissility x and the mass asymmetry value α are varied. As α increases for fixed x, the saddle-point configurations effectively behave like lighter (less fissile) nuclei. For fissilities less than the Businaro-Gallone value ($x_{\mathrm{BG})}$, the conditional saddle-point energy always decreases with increasing α. For x>$x_{\mathrm{BG}}$, with increasing α the conditional saddle-point energy increases until it reaches the limit of the Businaro-Gallone peak, after which the energy decreases.

Cross sections for ${\pi }^{+}$ and ${\pi }^{\mathrm{-}}$ elastic and inelastic scattering to states in ${}_{}{}^{15}{}_{}{}^{}\mathrm{N}$ have been measured at an incident pion energy of 164 MeV. Transitions to states at 10.7, 12.5, 14.0, and 17.2 MeV were found to contain significant M4 strength. The M4 assignments are supported both by angular distribution shapes and by additional ${\pi }^{+}$ cross sections measured at 120 and 260 MeV. The angular distributions are compared with distorted-wave impulse-approximation calculations to extract isoscalar and isovector spectroscopic amplitudes. These amplitudes are compared with model predictions.

Angular distributions of the deuteron tensor polarization, $t_{20}$, in π-d elastic scattering have been measured at pion energies of 180, 220, and 256 MeV. The experiment and analysis are described in detail. Theoretical calculations in which the effects of pion absorption on the elastic channel are small seem to reproduce the data. An excitation function was measured in order to search for a rap- id energy dependence of $t_{20}$. No rapid angular or energy dependence was found near a pion energy of 134 MeV, where other experiments have suggested the existence of dibaryon resonances.

We consider the manifestation of the quark presence in nuclei. We discuss deep-inelastic electron scattering at both high and low momentum transfer, and also discuss, at some length, elastic electron-nucleus scattering. Recent experiments have led to the conclusion that the quark distribution in nuclei differs from that which would be obtained from a collection of nucleons with properties unmodified from their free-space values. We stress, however, that if the properties of the nucleon are modified in the nucleus there are important consequences for the analysis of other, more traditional, nuclear physics experiments. We discuss nuclear structure functions near the (nucleon) quasielastic peak and show how modified nucleon properties can explain the quenching of the longitudinal response. Most of our discussion, however, is devoted to a study of nuclear charge distributions. We stress that what is being measured in these experiments is the quark charge distribution. We also provide approximate expressions for the quark charge density in terms of modified nucleon electromagnetic form factors and the nucleon density matrix. Numerical estimates of the size of various effects due to the modification of nucleon properties in nuclei are presented. Well-known difficulties found in relating theoretical charge distributions with those measured in electron scattering may be resolved in this approach since we show that only if the nucleon electromagnetic form factors are unmodified in nuclei is the standard analysis correct. Specifically we show that in the case of ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$, certain well-known problems found in relating theoretical and experimental charge densities can be largely resolved by using the matter densities of modern relativistic mean-field theories and the modified electromagnetic form factors we have calculated in an earlier work.

Angular distributions and excitation functions for inelastic scattering of ${\pi }^{+}$ and ${\pi }^{\mathrm{-}}$ from ${}_{}{}^{14}{}_{}{}^{}\mathrm{C}$ were measured at incident pion energies near the ${\Delta }_{33}$ resonance. Three states at excitation energies 11.7, 15.2, and 17.3 MeV were identified as $4^{\mathrm{-}}$ states. Isovector and isoscalar spectroscopic amplitudes $Z_0$ and $Z_1$, and equivalently, neutron and proton amplitudes $Z_{\mathrm{n}}$ and $Z_{\mathrm{p}}$ were deduced by comparison with microscopic distorted wave impulse approximation calculations. The 11.7-MeV state was found to be excited with a $Z_{\mathrm{n}/Z_{\mathrm{p}}}$ amplitude ratio of -1/3, resulting in a complete cancellation of the ${\pi }^{+}$ cross section. A nearly pure proton excitation was observed for the transition to the 17.3-MeV state. Both results are in qualitative agreement with the presented shell-model calculations. A poor correspondence with theory is found for the 15.2-MeV state. Data and distorted-wave impulse approximation calculations using shell-model wave functions are presented for the first $3^{\mathrm{-}}$ state at 6.73 MeV as an example of a transition dominated by ΔS=0 (no spin transfer). Its excitation function and angular-distribution shape contrast sharply with the transitions to the $4^{\mathrm{-}}$ states that proceed by ΔS=1.

The Pauli blocking effect on the pionic decay rate of ${}_{\mathrm{\Lambda }}{}^5{}_{}{}^{}\mathrm{He}$ is investigated with the Λ-α potential obtained from the hard-core Λ-N potential. The repulsive core of the Λ-N interaction reduces the Pauli blocking effect and enhances the pionic decay rate by about 30%. The lifetime of ${}_{\mathrm{\Lambda }}{}^5{}_{}{}^{}\mathrm{He}$ deduced from this investigation is in good agreement with the experimental one.

A four-body force due to the exchange of pions has been derived by means of It includes effects corresponding to pion-pion scattering, pion production, and pion-nucleon rescattering. The strength parameters of this four-body potential are typically one order of magnitude smaller than those of the two-pion-exchange three-body force.

We derive a K-matrix expression starting with three-body unitarity. This is then used to parametrize the results of a Faddeev πd→πd calculation whose poles are known. We find that the K-matrix method is unable to reproduce the known pole in the system when the width of that pole is greater than the width of the Δ resonance. This is explainable in terms of the approximations used in deriving the K matrix.

A special closed set of commutation relations satisfied by the fermion pair and multipole operators for a major shell in LST coupling is found. The case of the neutron (proton) p shell with the structure SO(7)⊃SU(3) is studied in detail. An exact Dyson boson mapping is constructed, which is subsequently hermitized. The method is directly applicable to higher shells and through the use of the experimentally plausible pseudo-SU(3) symmetry may lead to a theoretical foundation for the interacting boson model near the SU(3) limit.

The differential cross section for the reaction p(n,d)γ has been measured for center-of-mass angles between 0° and 65° at a neutron kinetic energy $T_{\mathrm{n}=185\mathrm{}}$ MeV. Assuming time-reversal invariance, our result is in essential agreement with the deuteron photodisintegration measurement at ${\theta }_{\mathrm{p}=0\mathrm{}}$° performed by Hughes et al. at Mainz. In addition to this confirmation of the absolute magnitude, our results, for the first time, provide information on the shape of the cross section distribution near 0°, i.e., the region where existing theories show the largest differences. This paper contains a detailed account of the experiment and a comparison with relevant experimental information. A discussion of some theoretical implications is also included. The best agreement with our data is obtained from these theories where relativistic corrections to the charge density are taken into account.

Photoneutron time-of-flight spectra from the ${}_{}{}^{14}{}_{}{}^{}\mathrm{C}$(γ,${\mathrm{n}}_0$${)}^{13}$C reaction were measured as functions of laboratory angle over the excitation energy region from 10 to 28 MeV. Angular distribution coefficients and differential cross sections were extracted as functions of excitation energy between 10 and 23 MeV. The angle-integrated ground-state cross section indicates that ground state transitions dominate the $T_{<}$ giant dipole resonance region below 13 MeV, but only contribute about 50% of the strength in the neutron channel in the rest of the giant dipole resonance region. The results support a mechanism of dominant E1 absorption in the energy region from 13 to 23 MeV where an average value of $a_2$=-0.5 indicates $p_{1/2}$→$d_{3/2}$ single-particle neutron transitions. Angular distribution information suggests that much of a prominent resonance at 11.3 MeV (with an integrated cross section of about 1.03 MeV mb) is due to an M1 transition from the ground state of ${}_{}{}^{14}{}_{}{}^{}\mathrm{C}$. If this is the case, there is little fragmentation of the M1 strength in ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ brought about by the presence of valence neutrons. When combined with the observation of the lack of a pygmy E1 resonance below the giant dipole resonance region, these results suggest that a model of ${}_{}{}^{14}{}_{}{}^{}\mathrm{C}$ as a ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ ‘‘core’’ with two valence, weakly coupled, neutrons is inappropriate. Below an excitation energy of about 19 MeV, there is reasonably good quantitative and qualitative agreement between the present data and the results of a recent shell model calculation.

The resonating group Faddeev method is formulated and applied to d-α elastic and breakup scattering. The effective interaction of the three-cluster resonating group model for the neutron, proton, and α particle is approximated by the fish bone optical model potential and decomposed into two-body and three-body potentials. The three-body potential is neglected, after being reduced in strength by an off-shell transformation. The two-body potentials are fitted to subsystem on-shell data. Equivalence of subsystem wave functions with resonating group wave functions is checked. Results of the numerical calculation indicate that the three-body observables are sensitive to Pauli effects but are not sensitive to the (unknown) high energy behavior of two-body phase shifts.

States in ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ at 12.71, 16.11, 18.38, 19.55, and 20.62 MeV were populated strongly in the ${}_{}{}^{11}{}_{}{}^{}\mathrm{B}$(d,n${)}^{12}$C reaction at a laboratory beam energy of 12 MeV. The charged-particle decays of these states were measured in coincidence with neutrons detected by time of flight techniques at 0° relative to the beam. Decay protons and α particles were detected and identified in a surface-barrier counter telescope placed at laboratory angles of 45°, 60°, 85°, 110°, and 135°. Angular correlations and branching ratios were determined for the decay particles. The 19.55 MeV peak contains at least two states 300 keV apart with very different α and proton decay rates. An α decay branch to the ground state of ${}_{}{}^8{}_{}{}^{}\mathrm{Be}$ indicates the presence of a natural parity state in the 18.38 MeV peak. Comparisons have been made between the measured angular correlations and calculations based on the ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ alignments predicted by the distorted-wave Born approximation.

The properties of the seven-nucleon system are examined with a multiconfiguration and multi- channel resonating-group calculation. The cluster internal functions employed explain the charge-form-factor data over a wide range of $q^2$ and satisfy the variational stability condition quite well. The model space used is spanned by ${}_{}{}^3{}_{}{}^{}$H+α, n${+\mathrm{}}^6$Li, n${+\mathrm{}}^6$${\mathrm{Li}}^{\mathrm{*}}$, and d${+\mathrm{}}^5$He cluster configurations. The result shows that the specific distortion of the ${}_{}{}^3{}_{}{}^{}$H+α system is quite significant. With our multiconfiguration calculation, the ground-state energy is improved by more than 1 MeV. The calculated level spectrum agrees well with the level spectrum empirically determined. The energy positions of both natural-parity and unnatural-parity levels are reasonably explained. In addition, we find that, because of centrifugal-barrier effects, the aligned configuration generally makes the most sig- nificant contribution. The characteristics of nucleon-exchange terms are also briefly examined. Here it is found that, at sufficiently high energies where sharp resonance levels do not exist, the essential properties of these terms can already be learned by performing relatively simple single-configuration calculations.

An ultralow energy K-capture branch in the decay of 180-yr ${}_{}{}^{158}{}_{}{}^{}\mathrm{Tb}$ has recently been suggested to offer very favorable energetics for investigating the electron neutrino mass. The ${}_{}{}^{158}{}_{}{}^{}\mathrm{Tb}$ Q value relative to ${}_{}{}^{158}{}_{}{}^{}\mathrm{Gd}$ has been measured by means of a (p,d) reaction on a radioactive ${}_{}{}^{158}{}_{}{}^{}\mathrm{Tb}$ target. The ground state electron capture Q value of 1215.4(4.3) keV, inferred here, precludes ${}_{}{}^{158}{}_{}{}^{}\mathrm{Tb}$ K electron capture to the 1187 keV state of ${}_{}{}^{158}{}_{}{}^{}\mathrm{Gd}$.