Pion Absorption on Polarized Lithium-7 at 165 MeV

<p>Pion absorption is not well understood. Cross section data alone does not provide a complete description since the cross section tends to be sensitive only to the spin-independent terms in the transition amplitude. Polarization observables are thus necessary to complete the picture. In this experiment, analyzing powers for the reaction ^7→Li(π⁺,pp)⁵He at T_π = 165 MeV were measured at the Paul Scherrer Institut, Switzerland. The emitted protons were detected with the SUSI spectrometer at 38° in coincidence with an array of five scintillator telescopes centered around the quasi-free angle for absorption on a nucleon pair. Theoretical predictions were made using a Distorted Wave Impulse Approximation (DWIA) and assuming that the absorption occurs on deuteron-like nucleon pairs. The measured analyzing powers were found to be consistent with zero in complete disagreement with the DWIA predictions. The reason for the discrepancy may be attributed to the reaction mechanism and the nuclear structure input to the DWIA, indicating a need for a more microscopic calculation.</p>

Name thesis:degree_name

Doctor of Philosophy (PhD)

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physics

Year dc:date.available

1996

Author dc:creator

• Greco, Thomas A.

Contributors dc:contributor

• Andreas Klein
• J. Wallace Van Orden

• Intermediate energy
• Pions
• Nuclear

Statement dc:rights

• <p>In Copyright. URI: <a href="http://rightsstatements.org/vocab/InC/1.0/">http://rightsstatements.org/vocab/InC/1.0/</a> This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).</p>

Repository record dc:identifier

https://digitalcommons.odu.edu/physics_etds/42

OAI identifier oai:identifier

oai:digitalcommons.odu.edu:physics_etds-1047