A relativistic, partial wave $\frac{N}{D}$ dispersion theory is developed for low energy pion-nucleon elastic scattering. The theory is simplified by treating crossing symmetry only to lowest order in the inverse nucleon mass. The coupling of elastic scattering to inelastic channels is included by taking the necessary inelasticity from experimental data. Three models are examined: pseudoscalar coupling of pions and nucleons, pseudovector coupling, and a model in which all intermediate antinucleons are projected out of the amplitude. The phase shifts in the dominant $P_{33}$ channel are quantitatively reproduced for $P_{\mathrm{lab}}\le 1.2$ GeV/c with a pion-nucleon vertex of range 1110 MeV/c. We find that there are large (not of the order of the inverse nucleon mass) kinematic corrections to Chew-Low models, and that the Chew-Low model is successful because a reduction in the pion-nucleon cutoff provides a remarkable compensation for the large kinematic corrections. The intermediate antinucleon states are found to provide a significant fraction of the interaction in both $S$ and $P$ waves, and the model which explicitly removes them is incompatible with the $P_{33}$ phase shifts. Thus a model of the pion-nucleon interaction which does not include antinucleon degrees of freedom is found to be unphysical.

NUCLEAR REACTIONS Pion-nucleon scattering, kinematic corrections, role of intermediate antinucleon states.

We have performed proton inclusive scattering measurements at 500 MeV on ${}_{}{}^4{}_{}{}^{}\mathrm{He}$, Ni, and Ta at angles at 65°, 90°, 120°, and 160°. Analyzing powers were also obtained for ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ and Ni. The data extend in energy to the elastic scattering peak for ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ at 90°. The cross-section data are described well by a direct knockout model and by quasi-two-body scaling calculations. Fits to analyzing power results by these theories are poor, and furthermore, we find a qualitative difference between the ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ and Ni results. The Ni data show large positive analyzing powers at high detected particle energies, in keeping with results obtained on various targets from ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ to ${}_{}{}^{181}{}_{}{}^{}\mathrm{Ta}$ at 800 MeV bombarding energy; the ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ analyzing powers are predominantly negative or close to zero.

NUCLEAR REACTIONS Proton inclusive scattering; ${}_{}{}^4{}_{}{}^{}\mathrm{He}$, Ni, ${}_{}{}^{181}{}_{}{}^{}\mathrm{Ta}$; $E=500\mathrm{}$ MeV; measured $\sigma \left(E_p\right)$, $P\left(E_p\right)$.

A simple isospin model of inelastic pion-nucleus scattering is discussed and quantitative results compared with recent experiments on light nuclei.

NUCLEAR REACTIONS ${}_{}{}^{13}{}_{}{}^{}\mathrm{C}$, ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}(\pi ,{\pi }^{\prime })$ (3, 3) resonance energy to stretched configuration states; ratios of $\frac{{\pi }^{-}}{{\pi }^{+}}$ and isoscalar-isovector transitions estimated; effects of isospin ½ reaction channel ascertained.

The absorption rate for a low energy pion in infinite nuclear matter has been calculated in the random phase approximation. It is found that particle-hole plus phonon states can play as important a role as that played by two-particle-two-hole states. The calculated imaginary part of the optical potential is compared with the results of recent phenomenological analyses.

NUCLEAR REACTIONS Pion absorption calculated at and near threshold in nuclear matter, taking into account particle-hole plus phonon states and two-phonon states as well as two-particle-two-hole states.

The three-body final-state reaction of charged single-pion production, $pp\to {\pi }^{+}\mathrm{pn}$, and that for charged double-pion production, $pp\to {\pi }^{-}{\pi }^{-}pp$, have been studied at $T_P=800\mathrm{}$ MeV by measuring the momentum spectra for ${\pi }^{+}$ and ${\pi }^{-}$ emitted from proton-proton collisions. The momentum spectra for single-pion production are fit with the peripheral model calculations of VerWest, and a similar model by one of us is discussed. The spectra for double-pion production follow an extrapolation of the Lindenbaum and Sternheimer model from higher energies toward threshold. This result is in disagreement with the results of Cochran et al.

NUCLEAR REACTIONS Pion production in the two-nucleon system: $pp\to {\pi }^{+}\mathrm{pn}$, $pp\to {\pi }^{-}{\pi }^{+}pp$; $E_p=800\mathrm{}$, $\theta =16.5\mathrm{}°-60°$. Observed $\frac{d^2\sigma }{d\Omega d{q}_{\pi }}$. Peripheral model analyses.

The width $\Gamma$ and the potential well depth $-V_{\Sigma }$ of the $\Sigma$ hyperon in nuclear matter are calculated with the help of the Brueckner theory. Results obtained for $\Gamma$ and $V_{\Sigma }$ with model D of the Nijmegen baryon-baryon interaction and simple estimates of $\Gamma$ in terms of the cross section for the ${\Sigma }^{-}p\to \Lambda n$ process are consistent with empirical estimates. It is shown that the exclusion principle and dispersive effects strongly suppress the $\Sigma N\to \Lambda N$ process in nuclear matter and are capable of reducing $\Gamma$ to values suggested by recent ($K,\pi$) experiments.

NUCLEAR STRUCTURE Energy and width of $\Sigma$ hyperon in nuclear matter calculated; $\Sigma N$ interaction with $\Sigma \Lambda$ coupling.

Electron capture decay of ${}_{}{}^{135}{}_{}{}^{}\mathrm{Ce}$ (17.6 h) has been used to determine the mass difference between ${}_{}{}^{135}{}_{}{}^{}\mathrm{Ce}$ and ${}_{}{}^{135}{}_{}{}^{}\mathrm{La}$. The main component of the positrons (0.36%/decay) was found to feed the 300 keV level in ${}_{}{}^{135}{}_{}{}^{}\mathrm{La}$ with triple coincidences between two annihilation radiations and $\gamma$ rays. The end-point energy of the ${\beta }^{+}$ main component was determined to be 694 ± 13 keV. Thus the mass difference between ${}_{}{}^{135}{}_{}{}^{}\mathrm{Ce}$ and ${}_{}{}^{135}{}_{}{}^{}\mathrm{La}$ is determined to be 2016 ± 13 keV. No anomaly is found for the $\frac{\mathrm{EC}}{{\beta }^{+}}$ ratio.

RADIOACTIVITY ${}_{}{}^{135}{}_{}{}^{}\mathrm{Ce}$ [from ${}_{}{}^{139}{}_{}{}^{}\mathrm{La} \mathrm{}(p,5n)\mathrm{}$]; measured $E_{\beta }$, $\gamma {\gamma }^{\pm }{\gamma }^{\pm }$ coin; deduced $Q$. Magnetic spectrometer, Ge(Li) and NaI(Tl) detectors.

The isotopes ${}_{}{}^{206}{}_{}{}^{}\mathrm{Fr}$ and ${}_{}{}^{208}{}_{}{}^{}\mathrm{Fr}$ were produced by the reactions $\mathrm{Ir}({}_{}{}^{20}{}_{}{}^{}\mathrm{Ne},xn){}_{}{}^{206,208}{}_{}{}^{}\mathrm{Fr}$ and mass separated on-line. The electron-capture and positron decays to ${}_{}{}^{206}{}_{}{}^{}\mathrm{Rn}$ and ${}_{}{}^{208}{}_{}{}^{}\mathrm{Rn}$ were studied by collecting $\gamma$ ray and internal conversion electron singles spectra as a function of decay time as well as $\gamma -\gamma$, $\gamma -e^{-}$, and $\gamma -\mathrm{x}$ ray coincidence spectra. The energies and many of the spins were determined for 18 excited, even parity states in ${}_{}{}^{208}{}_{}{}^{}\mathrm{Rn}$ and for 10 excited, even parity states in ${}_{}{}^{206}{}_{}{}^{}\mathrm{Rn}$. These nuclei appear to be excellent candidates for interpretation in terms of a weak coupling shell model. The energy levels were also compared to the predictions of the interacting boson approximation model.

RADIOACTIVITY ${}_{}{}^{206,208}{}_{}{}^{}\mathrm{Fr}$ from mass separated products of ${}_{}{}^{\mathrm{nat}}{}_{}{}^{}\mathrm{Ir}({}_{}{}^{20}{}_{}{}^{}\mathrm{Ne},xn){}_{}{}^{206,208}{}_{}{}^{}\mathrm{Fr}$. Measured $E_{\gamma }$, ICC, $\gamma -\gamma -t$, $e^{-}\gamma -t$. Deduced levels $E$, $J$, $\pi$ in ${}_{}{}^{206,208}{}_{}{}^{}\mathrm{Rn}$.

The $\beta$ and subsequent $\gamma$ decays of ${}_{}{}^{90}{}_{}{}^{}\mathrm{Rb}_{}^g{}_{}{}^{}$ and ${}_{}{}^{90}{}_{}{}^{}\mathrm{Rb}_{}^m{}_{}{}^{}$ have been studied using an on-line isotope separator system. Ge(Li) $\gamma$-ray singles and $\gamma -\gamma$ coincidence measurements were used to construct level schemes for ${}_{}{}^{90}{}_{}{}^{}\mathrm{Sr}$. The decays of the two ${}_{}{}^{90}{}_{}{}^{}\mathrm{Rb}$ activities were distinguished using a set of four experiments in which the collection and observation parameters were adjusted to change the relative decay intensities. For the decay of ${}_{}{}^{90}{}_{}{}^{}\mathrm{Rb}_{}^g{}_{}{}^{}$, 83 attributed $\gamma$-ray transitions were placed among 33 excited states of ${}_{}{}^{90}{}_{}{}^{}\mathrm{Sr}$, whereas for the decay of ${}_{}{}^{90}{}_{}{}^{}\mathrm{Rb}_{}^m{}_{}{}^{}$, 43 excited states of ${}_{}{}^{90}{}_{}{}^{}\mathrm{Sr}$ provided placement for 108 attributed $\gamma$ rays. Twelve $\gamma$ rays were not placed in either level scheme, and 42 transitions are common to both decays. Spin and parity assignments have been deduced using $\gamma$-decay $log\mathrm{ft}$ values, $\gamma -\gamma$ angular correlation data, and reaction data in the literature. Interpretation of some of the energy levels is made from a shell-model viewpoint.

RADIOACTIVITY ${}_{}{}^{90}{}_{}{}^{}\mathrm{Rb}_{}^g{}_{}{}^{}$, ${}_{}{}^{90}{}_{}{}^{}\mathrm{Rb}_{}^m{}_{}{}^{}$ [decay products of ${}_{}{}^{90}{}_{}{}^{}\mathrm{Kr}$ from ${}_{}{}^{235}{}_{}{}^{}\mathrm{U}\mathrm{}(n,f)\mathrm{}$]; measured $E_{\gamma }$, $I_{\gamma }$, $\gamma -{\gamma }^{\mathrm{coin}}$, $\gamma {\gamma }^{\theta }$. Ge(Li) and NaI(Tl) detectors. ${}_{}{}^{90}{}_{}{}^{}\mathrm{Sr}$ deduced levels, $J$, $\pi$, $log\mathrm{ft}$. Mass-separated ${}_{}{}^{90}{}_{}{}^{}\mathrm{Kr}$ activity.

The quadrupole interaction frequencies ${\nu }_Q=\frac{e^2\mathrm{qQ}}{h}$ of radioactive ${}_{}{}^{182,183,184,186,188}{}_{}{}^{}\mathrm{Re}$ in a Re single crystal have been determined by the nuclear orientation technique at temperatures down to 3 mK as - 223(21), - 262(24), - 390(33), - 104(14), and - 103(16) MHz, respectively. With the known electric field gradient $eq\left(\mathrm{Re}Re\right)=-4.87\mathrm{}\left(15\right)\mathrm{}\times {10}^{17}$ ${\mathrm{V}/\mathrm{c}\mathrm{m}}^2$ the following ground-state quadrupole moments are deduced: $Q({}_{}{}^{182}{}_{}{}^{}\mathrm{Re};2^{+})=+1.9\mathrm{}\left(2\right)\mathrm{}$ b; $Q({}_{}{}^{183}{}_{}{}^{}\mathrm{Re};\frac{5}{2^{+}})=+2.2\mathrm{}\left(2\right)\mathrm{}$ b; $Q({}_{}{}^{184}{}_{}{}^{}\mathrm{Re};3^{-})=+3.3\mathrm{}\left(3\right)\mathrm{}$ b; $Q({}_{}{}^{186}{}_{}{}^{}\mathrm{Re};1^{-})=+0.88\mathrm{}\left(12\right)\mathrm{}$ b; $Q({}_{}{}^{188}{}_{}{}^{}\mathrm{Re};1^{-})=+0.88\mathrm{}\left(14\right)\mathrm{}$ b.

RADIOACTIVITY ${}_{}{}^{182}{}_{}{}^{}\mathrm{Re}$ from ${}_{}{}^{185}{}_{}{}^{}\mathrm{Re}\mathrm{}(d,5n)\mathrm{}$, ${}_{}{}^{183,184}{}_{}{}^{}\mathrm{Re}$ from ${}_{}{}^{186,188}{}_{}{}^{}\mathrm{Re}$ from ${}_{}{}^{183,184}{}_{}{}^{}\mathrm{W}\mathrm{}(d,2n)\mathrm{}$, ${}_{}{}^{185,187}{}_{}{}^{}\mathrm{Re}(n,\gamma )$; measured $I_{\gamma }(\theta ,T)$ of oriented states. Deduced $Q_0$, $Q$ of ground states. Hyperfine enhanced nuclear cooling.

The half-life of ${}_{}{}^{241}{}_{}{}^{}\mathrm{Pu}$ was determined by studying the ingrowth of ${}_{}{}^{241}{}_{}{}^{}\mathrm{Am}$ in two independent sets of experiments: (i) by $\alpha$ spectrometry taking ${}_{}{}^{242}{}_{}{}^{}\mathrm{Pu}$ as well as ${}_{}{}^{239}{}_{}{}^{}\mathrm{Pu}$ and ${}_{}{}^{240}{}_{}{}^{}\mathrm{Pu}$ as reference isotopes, and (ii) by $\alpha$ proportional counting. In these experiments, separate synthetic mixtures, prepared by mixing different isotopes of plutonium, were used with an objective of obtaining periodically a desired change in the $\alpha$ activity ratio (as in $\alpha$ spectrometry) or in the total $\alpha$ activity (as in $\alpha$ proportional counting) and to measure this change with high precision and accuracy. In $\alpha$ spectrometry, from the 65 measurements carried out on five electrodeposited sources over a period of 574 days, a value of 14.37±0.09 yr was obtained for the half-life of ${}_{}{}^{241}{}_{}{}^{}\mathrm{Pu}$. In the $\alpha$ proportional counting, from the 20 measurements carried out on five sources over a period of 704 days, a value of 14.50±0.08 yr was obtained. The average of these two independent determinations leads to a value of 14.44±0.06 yr for the half-life of ${}_{}{}^{241}{}_{}{}^{}\mathrm{Pu}$. The uncertainty quoted on the values is a combination of one standard deviation on the average value and the error evaluated from estimates on various error components. The half-life obtained in this work is in good agreement with the results reported earlier from this laboratory by $\alpha$ spectrometry, taking ${}_{}{}^{239}{}_{}{}^{}\mathrm{Pu}$ and ${}_{}{}^{240}{}_{}{}^{}\mathrm{Pu}$ as reference isotopes as well as with the preliminary results reported by other laboratories using different methods.

RADIOACTIVITY ${}_{}{}^{241}{}_{}{}^{}\mathrm{Pu}$ half-life, $\alpha$ spectrometry using ${}_{}{}^{242}{}_{}{}^{}\mathrm{Pu}$ as well as ${}_{}{}^{239}{}_{}{}^{}\mathrm{Pu}$ and ${}_{}{}^{240}{}_{}{}^{}\mathrm{Pu}$ as reference isotopes; measured $\alpha$ activity ratio by $\alpha$ spectrometry, isotopic composition by mass spectrometry; $\alpha$ proportional counting; measured $\alpha$ activity by gas flow proportional counter, concentration by isotope dilution mass spectrometry.

Recently Ballot and Fabre de la Ripelle pointed out that the central depression in the "empirical" point proton distribution of ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ could be attributed to the two-pion-exchange three-body force. We examine this mechanism by constructing simple phenomenological wave functions of the form of $f\left(x\right)f\left(y\right)f\left(z\right)\mathrm{}{[1-\Sigma g\left(x\right)g\left(y\right)(3\mathrm{}{cos}^2{\theta }_z-1)]}^n$, where $x$, $y$, and $z$ are the interparticle distances, $cos{\theta }_z=\frac{\overrightarrow{\mathrm{x}}·\overrightarrow{\mathrm{y}}}{\mathrm{xy}}$, $n=\frac{1}{2} or 1$, and $\Sigma$ implies the cyclic summation over $x$, $y$, and $z$. The angle dependent term simulates the effect of the two-pion-exchange three-body force. We find that the density near the origin is indeed very sensitive to the angle dependent term of the model wave function, and the central depression can be easily fitted. The analysis is extended to ${}_{}{}^4{}_{}{}^{}\mathrm{He}$, with similar results. We then try to relate the model wave function of ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ to the two-pion-exchange three-body force by a variational calculation. About one third of the phenomenological angle dependent term can be obtained, but the result is quite sensitive to the short-range part of the three-body force.

NUCLEAR STRUCTURE Charge distributions of ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ and ${}_{}{}^4{}_{}{}^{}\mathrm{He}$, effect of three-body force.

We reexamine the intermediate state convergence problem for the core polarization diagram ($G_{3\mathrm{p}1\mathrm{h}}$) in the expansion of an effective shell-model interaction using a modern meson exchange Bonn-Jülich potential in comparison to the phenomenological Reid soft-core interaction. The Bonn-Jülich $N-N$ potential contains a much weaker tensor force as compared with the Reid soft-core interaction. As a consequence its repulsive contributions to $G_{3\mathrm{p}1\mathrm{h}}$ from high momentum intermediate particle states are much reduced and $G_{3\mathrm{p}1\mathrm{h}}$ can be calculated in a good approximation with $2\hslash \omega$ particle-hole excitations alone. This opens up the possibility of calculating higher order processes in a reliable and expendient way. We have further determined the spectra of ${}_{}{}^{18}{}_{}{}^{}\mathrm{O}$ and ${}_{}{}^{18}{}_{}{}^{}\mathrm{F}$ using the folded diagram perturbation theory to determine the effective interaction. The energy levels are best reproduced by the Bonn-Jülich $N-N$ potential.

NUCLEAR STRUCTURE ${}_{}{}^{18}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{18}{}_{}{}^{}\mathrm{F}$; dependence of effective interaction on $N-N$ tensor force. Convergence of intermediate state summation in core polarization.

The nuclei ${}_{}{}^{187}{}_{}{}^{}\mathrm{Ir}$, ${}_{}{}^{187}{}_{}{}^{}\mathrm{Os}$, and ${}_{}{}^{189}{}_{}{}^{}\mathrm{Ir}$ are described in terms of a quasiparticle coupled to the neighboring even-even nuclei ${}_{}{}^{188}{}_{}{}^{}\mathrm{Os}$ and ${}_{}{}^{188}{}_{}{}^{}\mathrm{Pt}$. The wave functions of the various levels of the ground and $\gamma$ bands of these even-even nuclei have been previously determined in a microscopic triaxial theory, where variation after angular momentum projection from triaxailly symmetric intrinsic wave functions is performed in the framework of a Hartree-BCS model employing the pairing $+Q·Q$ interaction of Baranger and Kumar. The level energies of both the negative as well as positive parity bands of the odd $A$ nuclei are calculated. On the basis of their wave functions, these levels have been classified into various bands. The comparison with experiment is reasonably good. Also, many $B\left(E2\mathrm{}\right)\mathrm{}$ values, electromagnetic moments, and $B\left(M1\mathrm{}\right)\mathrm{}$ values so calculated compare well with experiment. Predictions for many new levels have been made. Thus taking the Hamiltonian of Baranger and Kumar, it has been possible to describe the properties of both the even-even and neighboring odd $A$ nuclei simultaneously in a consistent manner without any adjustable free parameter.

NUCLEAR STRUCTURE Microscopic triaxial description of odd $A$ nuclei. Even-even core determined previously by variation after angular momentum projection, pairing $+Q·Q$ interaction, Hartree-BCS theory.

We present the complete momentum space three-nucleon potential of the two-pion-exchange type in the partial wave decomposition needed for the Faddeev equations of the three-nucleon bound state. The potential arises from an off-mass-shell model for $\pi N$ scattering based upon current algebra and a dispersion-theoretical axial vector amplitude dominated by the $\Delta \mathrm{}\left(1230\right)\mathrm{}$ isobar. The potential is manifestly Hermitian and defined for all three nucleon momenta. We display some matrix elements of the potential in the five three-body partial waves corresponding to the ${}_{}{}^1{}_{}{}^{}S_0^{}{}_{}{}^{}$ and ${}_{}{}^3{}_{}{}^{}S_1^{}{}_{}{}^{}-{}_{}{}^3{}_{}{}^{}D_1^{}{}_{}{}^{}$ states of the two-body subsystem. These matrix elements show a striking contrast to those of an older three-body potential mediated only by the $\Delta \mathrm{}\left(1230\right)\mathrm{}$ $p$-wave resonance.

NUCLEAR STRUCTURE Three-body potential; few-nucleon system, Faddeev approach, partial wave decomposition in Jacobi variables.

An independent particle model is obtained from the fundamental constrained variational equations for a many-body system by making certain assumptions. The resulting model contains the attractive feature of the Nilsson model but has the advantage of a traceable connection to the exact equations and thus is more amenable to interpretation. In particular, the energy deformation surface is calculated using the new model and is shown to differ significantly from the one obtained in the usual approach.

NUCLEAR STRUCTURE Modified independent particle model proposed and compared to that of Nilsson.

We present a procedure which allows the extension of linear-response calculations to open-shell nuclei. Using simple and intermediate coupling shell model wave functions for the ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ ground state we apply our procedure to calculate the characteristics of multipole giant resonances. Our results agree well with experiment and are compatible with the predictions of other open-shell random phase approximation models.

NUCLEAR STRUCTURE Extended linear response random phase approximation to open shell nuclei. Strength distributions for $L=1\mathrm{}-3$ electric transitions in ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$.

The reaction ${}_{}{}^{209}{}_{}{}^{}\mathrm{Bi}(\overrightarrow{d},p)$ has been used to study the structure of the ground state multiplet of ${}_{}{}^{210}{}_{}{}^{}\mathrm{Bi}$. The cross section and vector analyzing power were measured at $E_d=12\mathrm{}$ MeV for angles between 65° and 100°. No evidence of configuration mixing was seen in the analyzing power measurements. The cross section measurements confirm previous observations of fragmentation of the $8^{-}$ level at 580 keV.

NUCLEAR REACTIONS ${}_{}{}^{209}{}_{}{}^{}\mathrm{Bi}(\overrightarrow{d},p)$, $E_d=12.0\mathrm{}$ MeV; measured $\sigma \left(\theta \right)$, $i{T}_{11}\left(\theta \right)$ for $65°<\theta <100\mathrm{}°$; natural target.

Analyzing power measurements from the ($\overrightarrow{p},d$) reaction on ${}_{}{}^{90}{}_{}{}^{}\mathrm{Zr}$ and ${}_{}{}^{120}{}_{}{}^{}\mathrm{Sn}$ have been made using a 90 MeV polarized proton beam. The spin of the broad structure near 5 MeV excitation energy in ${}_{}{}^{119}{}_{}{}^{}\mathrm{Sn}$ has been unambiguously determined to be 9/2 from comparison with the empirical analyzing power for the ground state of ${}_{}{}^{89}{}_{}{}^{}\mathrm{Zr}$ and from distorted wave Born approximation calculations.

NUCLEAR REACTIONS ${}_{}{}^{90}{}_{}{}^{}\mathrm{Zr}\mathrm{}(p,d)\mathrm{}$, ${}_{}{}^{120}{}_{}{}^{}\mathrm{Sn}\mathrm{}(p,d)\mathrm{}$ $E=90\mathrm{}$ MeV; polarized beam, measured $\sigma \left(\theta \right)$, $A_y\left(\theta \right)$ DWBA analysis, deduced by $J^{\pi }$, resolution 100 keV.

Excitation functions are presented for the reactions ${}_{}{}^{68}{}_{}{}^{}\mathrm{Zn}(p,\gamma ){}_{}{}^{69}{}_{}{}^{}\mathrm{Ga}$, ${}_{}{}^{68}{}_{}{}^{}\mathrm{Zn}(p,\alpha ){}_{}{}^{65}{}_{}{}^{}\mathrm{Cu}$, and ${}_{}{}^{68}{}_{}{}^{}\mathrm{Zn}\mathrm{}(p,n)\mathrm{}{}_{}{}^{68}{}_{}{}^{}\mathrm{Ga}$. The first two reactions show substantial competition effects above the neutron threshold. Global Hauser-Feshbach calculations using particle transmission functions deduced from optical model analysis of elastic scattering data agree well with the results. Calculations using transmission functions obtained from the equivalent square-well representation of the optical potential are less successful, probably because of inadequate experimental information on particle strength functions.

NUCLEAR REACTIONS ${}_{}{}^{68}{}_{}{}^{}\mathrm{Zn}(p,\gamma )$, $E=1.67\mathrm{}-4.97$ MeV; ${}_{}{}^{68}{}_{}{}^{}\mathrm{Zn}(p,\alpha )$, $E=3.36\mathrm{}-5.48$ MeV; ${}_{}{}^{68}{}_{}{}^{}\mathrm{Zn}\mathrm{}(p,n)\mathrm{}$, $E=3.77\mathrm{}-5.03$ MeV; measured $\sigma \mathrm{}\left(E\right)\mathrm{}$; Hauser-Feshbach calculations. Enriched targets.