Pion elastic scattering from polarized {sup 13}C in the energy region of the P{sub 33} resonance

Technical Report · Sat Aug 01 04:00:00 EDT 1992

OSTI ID:10179734

Yifen, Yen ^[1]

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1. Minnesota Univ., Minneapolis, MN (United States). Dept. of Physics and Astronomy

Asymmetries (A{sub y}) and differential cross sections (d{sigma}/d{Omega}) were measured for {pi}{sup +} and {pi}{sup {minus}} elastic scattering using polarized and unpolarized {sup 13}C targets. The experiment was done at the Los Alamos Meson Physics Facility with the pion beam from the Low Energy Pion channel. The scattered pions were detected with the Large Acceptance Spectrometer. The {sup 13}C nuclei in {sup 13}C-enriched 1-butanol were polarized by the dynamic nuclear polarilization method. Angular distributions of both A{sub y} and d{sigma}/d{Omega} were measured below the P{sub 33} resonance at the incident energy of 130 MeV for {pi}{sup +} and {pi}{sup {minus}}, and above the resonance at 223 MeV for {pi}{sup +} and at 226 MeV for {pi}{sup {minus}}. In addition, A{sub y} and d{sigma}/d{Omega} were measured in a range of momentum transfers, 1.75 {le} q {le} 2.05 fm{sup {minus}}, at several energies. At 130 MeV, the values of A{sub y} are significantly different from zero for {pi}{sup {minus}} scattering. For {pi}{sup +} at 130 MeV and for both {pi}{sup {minus}} and {pi}{sup +} at all other energies, the A{sub y} are mostly consistent with zero. Theoretical analyses were done using different nuclear structure models. The data were not reproduced by the presently available nuclear wave functions. It was found that the asymmetry is strongly sensitive to the quadrupole spin flip part of the transition. The data of this thesis complement measurements of the magnetic form factor from electron scattering. In attempts to fit both the asymmetry and the magnetic form factor, it was found that the pion asymmetry data are not reproduced by the wavefunctions which fit the magnetic form factor at low momentum transfers.

• Research Organization: Los Alamos National Lab., NM (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 10179734
• Report Number(s): LA--12373-T; ON: DE92040823
• Country of Publication: United States
• Language: English

Related Subjects

663460
663520
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
A = 6-19
ANGULAR DISTRIBUTION
ASYMMETRY
BEAM MONITORS
CARBON 13 TARGET
DATA ACQUISITION SYSTEMS
DIFFERENTIAL CROSS SECTIONS
ELASTIC SCATTERING
ELECTROMAGNETIC FORM FACTORS
ENERGY DEPENDENCE
MESON- AND HYPERON-INDUCED REACTIONS AND SCATTERING
MOMENTUM TRANSFER
NUCLEAR STRUCTURE
PION REACTIONS
POLARIZED TARGETS