Measurements of the spin observables D-NN ', P, and A(y) in inelastic proton scattering from C-12 and O-16 at 198 MeV - art. no. 034614

Citation
Ak. Opper et al., Measurements of the spin observables D-NN ', P, and A(y) in inelastic proton scattering from C-12 and O-16 at 198 MeV - art. no. 034614, PHYS REV C, 6303(3), 2001, pp. 4614
Citations number
56
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physics
Journal title
PHYSICAL REVIEW C
ISSN journal
0556-2813 → ACNP
Volume
6303
Issue
3
Year of publication
2001
Database
ISI
SICI code
0556-2813(200103)6303:3<4614:MOTSOD>2.0.ZU;2-X
Abstract
Precise values of the normal-component spin observables D-NN, P, and A(y) h ave been determined at an incident proton energy of 198 MeV for the T=0 (12 .71 MeV) and T=1 (15.11 MeV) 1+ states in C-12 for momentum transfers betwe en 80 and 250 MeV/c. and for the T=0 (17.78 and 19.81 MeV) and T=1 (18.98 M eV) 4(-) states in O-16 for momentum transfers of 225-400 MeV/c. The data a re compared with distorted wave impulse approximation calculations in which a microscopic treatment of the nuclear medium has been used to obtain an e ffective nucleon-nucleon interaction. Nuclear binding and Pauli blocking ef fects. as well as those due to the strong scalar and vector mean held poten tials that arise in covariant treatments of nuclear matter. are incorporate d using a G-matrix approach. Our results suggest that while the isovector c hannel of the effective nucleon-nucleon interaction is reasonably well unde rstood, pronounced discrepancies between theory and experiment for the isos calar transitions point towards problems with the relative strengths of the spin-orbit and tensor components. For the C-12 states, these discrepancies are more difficult to interpret due to ambiguities in the nuclear structur e.