Coincidence measurements of the (. pi. /sup +/,. pi. /sup 0/p) reaction in the /triangle/-resonance region

Technical Report · Mon May 01 04:00:00 EDT 1989

DOI:https://doi.org/10.2172/6031362· OSTI ID:6031362

Hoeibraten, S

This thesis describes an experimental study of the (..pi../sup +/, ..pi../sup 0/p) reaction at incident energy T/sub ..pi../sup +// = 165 MeV. This work is part of the first experiment to detect neutral pions and protons in coincidence in kinematically complete measurements. The reaction was studied on /sup 16/O (using water targets) at several pion angles: theta/sub ..pi../sup 0// = 70/degree/, 80/degree/, 110/degree/, and 130/degree/. At theta/sub ..pi../sup 0// = 110/degree/ measurements were also made on /sup 56/Fe, /sup 120/Sn, and /sup 208/Pb. The neutral pions were detected with the LAMPF ..pi../sup 0/ spectrometer, while the protons were detected in a vertical array of plastic-scintillator ..delta..E-E telescopes, each spanning 8.5 msr. Energy spectra of the differential cross sections d/sup 4/sigma/dE/sub ..pi../sup 0// dE/sub p/d..cap omega../sub ..pi../sup 0//d..cap omega../sub p/ were obtained for each proton telescope and subsequently integrated over proton and pion energy and proton angle. The characteristics of these spectra are consistent with a quasi-free description of the (..pi../sup +/,..pi../sup 0/p) reaction. The angular dependence of dsigma/d..cap omega../sub ..pi../sup 0//(theta/sub ..pi../sup 0//) for /sup 16/O(..pi../sup +/,..pi../sup 0/p) was found to be in accordance with that of the cross section for the corresponding free reaction at backward ..pi../sup 0/ angles. For the /sup 16/O(..pi../sup +/,..pi../sup 0/p) reaction, events in which a p-shell nucleon had been removed were identified. The p-shell events were found to constitute only 40--50% of the total cross section for quasi-free one-nucleon removal. The (..pi../sup +/,..pi../sup 0/p) cross section at theta/sub ..pi../sup 0// = 110/degree/ proved to be almost the same for all target nuclei, possibly slightly decreasing as a function of A. 102 refs., 108 figs., 24 tabs.

• Research Organization: Los Alamos National Lab., NM (USA)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 6031362
• Report Number(s): LA-11582-T; ON: DE89011400
• Country of Publication: United States
• Language: English

Related Subjects

651320* -- Nuclear Properties & Reactions
A=6-19
Experimental
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
BARYONS
CHARGED PARTICLE DETECTION
CHARGED-PARTICLE REACTIONS
COINCIDENCE METHODS
COUNTING TECHNIQUES
CROSS SECTIONS
DATA ACQUISITION SYSTEMS
DELTA BARYONS
DETECTION
DIFFERENTIAL CROSS SECTIONS
ELEMENTARY PARTICLES
ENERGY SPECTRA
FERMIONS
HADRON REACTIONS
HADRONS
MESON REACTIONS
N BARYONS
NUCLEAR REACTIONS
OXYGEN 16 TARGET
PHOSPHORS
PION DETECTION
PION PLUS REACTIONS
PION REACTIONS
PLASTIC SCINTILLATORS
RADIATION DETECTION
SPECTRA
TARGETS