Cross sections and analyzing powers for the(p→,n)reaction on3Heand4Heat 200 MeV
| Autor: | M. A. Franey, Daniel S. Carman, N. S. Chant, C. M. Riedel, M. A. Espy, Yan Alexander Wang, D. Dehnhard, J. W. Watson, B. Brinkmöller, Richard Madey, M. Palarczyk, L. C. Bland, J. L. Langenbrunner |
|---|---|
| Rok vydání: | 1998 |
| Předmět: | |
| Zdroj: | Physical Review C. 58:645-657 |
| ISSN: | 1089-490X 0556-2813 |
| DOI: | 10.1103/physrevc.58.645 |
| Popis: | Double-differential cross sections and analyzing powers A{sub y} for the ({rvec p},n) reactions on {sup 3}He and {sup 4}He were measured at 200 MeV between {theta}{sub lab}=0{degree} and 44{degree}. The neutron spectra from {sup 3}He({rvec p},n) are dominated by the quasifree scattering peak and show no evidence for resonances in the three-proton system. The spectra from {sup 4}He({rvec p},n) exhibit strong resonance behavior in the p{sup 3}He system at low relative p{sup 3}He energies owing to the excitation of known L=1 resonances in {sup 4}Li, but there is no distinct quasifree peak in the measured spectra. The experimental A{sub y} for {sup 3}He({rvec p},n), averaged over the experimental range of neutron energies, are similar to those for free nucleon-nucleon (NN) scattering, whereas for {sup 4}He({rvec p},n) the A{sub y} are generally larger than the free values. The cross sections at far forward angles for both {sup 3}He and {sup 4}He appear to be suppressed relative to the free {ital NN} cross sections by Pauli blocking. At most angles, the shapes of the cross section spectra from both {sup 3}He and {sup 4}He are reproduced by distorted-wave impulse approximation (DWIA) calculations using a quasifree scattering model. Specifically for {sup 4}He({rvec p},n),more » the model requires the use of an optical potential which has a strong L=1 potential resonance corresponding to the low-lying L=1 states in {sup 4}Li. {copyright} {ital 1998} {ital The American Physical Society}« less |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|