Differential cross sections for elastic and inelastic scattering of 800 MeV protons from 58Ni have been measured to momentum transfers of 4 fm−1. The elastic scattering data were fit using a phenomenological optical model potential. The inelastic scattering was analyzed in the distorted wave Born approximation (DWBA) to obtain deformation lengths.

New differential cross sections for 0.8 GeV proton inelastic excitation of the first 2 + and 4 + states in 58 Ni are compared with distorted wave Born approximation and coupled-channels predictions. Multistep processes and multi-phonon mixing are both shown to be important in describing the excitation of the 4 + state.

Angular distributions for the elastic and inelastic scattering of 0.8 GeV protons from /sup 12/C, /sup 13/C, and /sup 208/Pb have been measured. Reported are data for the ground, 4.4 MeV 2/sup +/, 7.6 MeV 0/sup +/, 9.6 MeV 3/sup -/, and 14.1 MeV 4/sup +/ states of /sup 12/C; the ground, 3.1 MeV 1/2/sup +/, 3.7 MeV 3/2/sup -/, 6.9 MeV 5/2/sup +/, 7.6 MeV 5/2/sup -/, and 11.9 MeV () states of /sup 13/C; and the ground, 2.6 MeV 3/sup -/, and 3.2 MeV 5/sup -/ states of /sup 208/Pb. Analyses of the elastic angular distributions are made using the partial wave formalism and the Kerman-McManus-Thaler approach to the nucleon-nucleus optical potential; a realistic spin-orbit term is included. The inelastic transitions are analyzed within the framework of the distorted-wave Born-approximation, using transition strengths consistent with previous low-energy studies of inelastic scattering. A simple single-particle-plus-excited-core model is used for /sup 13/C. In terms of this analysis, an assignment of J/sup ..pi../ = (5/2,7/2)/sup +/ is made for the 11.9 MeV state in /sup 13/C.

Angular distributions for the elastic and inelastic scattering of 0.8 GeV protons from $^{12}\mathrm{C}$, $^{13}\mathrm{C}$, and $^{208}\mathrm{Pb}$ have been measured. Reported are data for the ground, 4.4 MeV 2+, 7.6 MeV 0+, 9.6 MeV ${3}^{\ensuremath{-}}$, and 14.1 MeV 4+ states of $^{12}\mathrm{C}$; the ground, 3.1 MeV $\frac{1}{{2}^{+}}$, 3.7 MeV $\frac{3}{{2}^{\ensuremath{-}}}$, 6.9 MeV $\frac{5}{{2}^{+}}$, 7.6 MeV $\frac{5}{{2}^{\ensuremath{-}}}$, and 11.9 MeV (?) states of $^{13}\mathrm{C}$; and the ground, 2.6 MeV ${3}^{\ensuremath{-}}$, and 3.2 MeV ${5}^{\ensuremath{-}}$ states of $^{208}\mathrm{Pb}$. Analyses of the elastic angular distributions are made using the partial wave formalism and the Kerman-McManus-Thaler approach to the nucleon-nucleus optical potential; a realistic spin-orbit term is included. The inelastic transitions are analyzed within the framework of the distorted-wave Born-approximation, using transition strengths consistent with previous low-energy studies of inelastic scattering. A simple single-particle-plus-excited-core model is used for $^{13}\mathrm{C}$. In terms of this analysis, an assignment of ${J}^{\ensuremath{\pi}}={(\frac{5}{2}, \frac{7}{2})}^{+}$ is made for the 11.9 MeV state in $^{13}\mathrm{C}$.NUCLEAR REACTIONS $^{12,\phantom{\rule{0ex}{0ex}}13}\mathrm{C}$, $^{208}\mathrm{Pb}(p, {p}^{\ensuremath{'}})$, $E=0.8$ GeV; measured $\ensuremath{\sigma}(\ensuremath{\theta})$; enriched targets; resolution \ensuremath{\geqslant} 80 keV, ${\ensuremath{\theta}}_{\mathrm{c}.\mathrm{m}.}=2\ensuremath{-}40\ifmmode^\circ\else\textdegree\fi{}$, $\ensuremath{\Delta}\ensuremath{\theta}=0.2\ifmmode^\circ\else\textdegree\fi{}$. Optical potential analysis, DWBA, inelastic deformation lengths, ${\ensuremath{\beta}}_{l}R$.

J. FONG 1, T.S. BAUER, G.J. IGO, G. PAULETTA, R. RIDGE i, R. ROLFE l, j. SOUKUP 2, C.A. WHITTEN, Jr. Department of Physics, University of California, Los Angeles, CA 90024, USA G.W. HOFFMANN University of Texas, Austin, Texas 78712, and Los Alamos Scientific Laboratory, Los Alamos, NM87545, USA N. HINTZ, M. OOTHOUDT Department of Physics, University of Minnesota, Minneapolis, MN 55455, USA G. BLANPIED, R.L. LILJESTRAND Department of Physics, University of Texas at Austin, Austin, TX 78712, USA and T. KOZLOWSKI Brookhaven National Laboratory, Upton, NY 11973, USA Received 20 June 1978 The p-4He elastic cross section at 788 MeV has been measured for laboratory angles between 13.3 ° and 165.5 ° corre- sponding to a range of four-momentum-transfer, -t, from 0.11 to 4.19 GeV2/c 2 . Evidence is presented for a backward diffraction-like structure not previously observed (3.4 < -t < 4.22 GeV2/c2). In the region 1.6 < -t < -3.4 GeV2/c 2 a smooth fall off from the shoulder due to triple scattering is observed with no evidence for quadruple scattering. In the present letter we present the measurement of essentially the entire angular distribution for p-4He elastic scattering at 788 MeV. For the first time da/dt has been systematically studied in the intermediate range of angles as well as for the far backward angles, thus allowing a connection to be made between the direct amplitude and exchange amplitudes which may be important at back angles. In recent years there has been considerable exper- imental and theoretical work on the elastic scattering of protons on 4He at intermediate energies (order of 1 GeV). From an experimental point of view, this 1 Present address: Formal Computers Inc., 925 Westwood Boulevard, Los Angeles, Calif 90024. 2 Present address: Department of Physics, University of Al- berta, Edmonton T6G2J 1, Canada. elastic scattering process is relatively easy to study since the ground state of 4He is separated from a mul- tibody continuum by at least 20 MeV. With regard to theoretical interpretation of the data, the nuclear structure of 4He is reasonably well known so that proton:He elastic scattering is a good test for theo- ries of nucleon-nucleus elastic scattering at interme- diate energies. The experimental data can be used to study various effects on the reaction mechanism such as two body correlations in the nuclear wave func- tion [1], effects due to the spin dependence of the nucleon-nucleon amplitudes [2], the effects of iso- bar intermediate states [3], non-eikonal effects in the reaction mechanism [4-6], and exchange effects at backward angles [7]. Most of the past experimen- tal data, which include both cross section [8] and polarization measurements [9], have been taken for 205

Differential cross sections for elastic scattering of 0.8-GeV protons from /sup 12/C, /sup 58/Ni, and /sup 208/Pb have been measured. Preliminary analysis of the data in terms of the Kerman-McManus-Thaler formalism with spin-dependent nucleon-nucleon amplitudes shows sensitivity to details of proton and neutron matter distributions.

Differential cross sections for elastic scattering of 0.8-GeV protons from /sup 12/C, /sup 58/Ni, and /sup 208/Pb have been measured. Preliminary analysis of the data in terms of the Kerman-McManus-Thaler formalism with spin-dependent nucleon-nucleon amplitudes shows sensitivity to details of proton and neutron matter distributions.

Elastic scattering of α-particles from helium has been measured at bombarding energies of 0.85 and 0.65 GeV over the range of four momentum transfer from 0.9 to 3.8 (GeV/c)2. The results are compared with the predictions of an α-α potential obtained by a folding procedure using a p-4He potential and 4He charge distribution.

Techniques used in the particle identification and energy measurement of helium ions with several hundred MeV of kinetic energy are described. In a two arm array, magnetic rigidity, specific ionization, and time-of-flight measurements were employed in the forward arm, while time-of-flight, specific ionization and total energy measurements were employed in the recoil arm. Very clean particle identification was obtained for hydrogen and helium isotopes.

Measurements of the (α, 2α) reaction in the GeV region on 16O and 28Si are described. The results are compared with a calculation employing the plane wave impulse approximation (PWIA) and with a calculation employing the distorted wave impulse approximation (DWIA). The PWIA calculation reproduces the shape of the angular distribution of the observed quasi-elastic events. The main effect of the distortion introduced in the DWIA calculation is to attenuate the quasi-elastic cross section by a factor of five. As a consequence, the (α, 2α) reaction in the GeV region is expected to be more useful to measure the spectroscopic factor Neff than in the region below 100 MeV since the attenuation is considerably larger (≈ 103) in the latter case.