Measure of back angle cross sections of antiproton-nucleus elastic scattering at 48 and 180 MeV
Description
Antiproton-nucleus elastic scattering was studied in the LEAR ring at CERN. The scattering cross section at back angles (θ LAB = 142 to 164 deg inclusive) was measured using plastic scintillation detectors. Analysis of experimental data at 47 MeV for a CH target and at 182 MeV for CH, C12, 016, and 018 targets produces differential cross sections for back angles less than or equal to a few dozen microbarns. These results agree with theoretical microscopic predictions. The analysis improves understanding of antiproton-nucleus interaction and introduces a constraint on the construction of optical potentials. The antiproton-nucleus potential is shown to be highly absorbing, thereby excluding S type potentials, and removing the ambiguity arising from the analysis of antiprotonic atoms. The results also show that there is no attractive pocket in the real potential likely to lead to an increase of the back angle cross sections
Availability note (English)
MF available from INIS under the Report Number.Abstract (French)
La diffusion elastique antiproton-noyau a ete etudiee aupres de l'anneau d'Antiprotons de Basse Energie LEAR au CERN. La mesure aux angles avant inferieurs a 60 deg a ete realisee avec le spectrometre SPES II. Nous avons complete ces mesures, en etudiant la section efficace de diffusion aux angles arriere compris entre 142 et 164 deg avec un ensemble de detection compose de scintillateurs plastiques. L'analyse des donnees experimentales a 47 MeV pour la cible CH et a 182 MeV pour les cibles CH, 12C, 16O, et 18O conduit a des sections efficaces differentielles aux angles arriere inferieures ou egales a quelques dizaines de microbarns. Les resultats auxquels on a abouti sont compatibles avec les predictions microscopiques developpees par M. von Geramb qui reproduisent egalement de maniere tres satisfaisante les mesures faites aux angles avant. Notre analyse apporte par ailleurs une contribution notable a la determination de l'interaction antiproton-noyau et une contrainte supplementaire pour la construction des potentiels optiques. Les conclusions auxquelles on a abouti montrent que le potentiel antiproton-noyau est fortement absorbant, ce qui exclut les potentiels de type S et leve ainsi l'ambiguite qui decoule de l'analyse des donnees des atomes antiprotoniques, et qu'il n'existe pas de poche attactive dans le potentiel reel susceptible de conduire a une remontee des sections efficaces aux angles arriereFiles
20059063.pdf
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Additional details
Additional titles
- Original title (French)
- Mesure aux angles arriere de la section efficace de diffusion elastique antiproton-noyau a 48 MeV et 180 MeV
Publishing Information
- Imprint Pagination
- 129 p.
- Report number
- FRCEA-TH--158
INIS
- Country of Publication
- France
- Country of Input or Organization
- France
- INIS RN
- 20059063
- Subject category
- S73: NUCLEAR PHYSICS AND RADIATION PHYSICS;
- Resource subtype / Literary indicator
- Thesis
- Descriptors DEI
- ANTIPROTON REACTIONS; CARBON 12 TARGET; CERN LEAR; DIFFERENTIAL CROSS SECTIONS; ELASTIC SCATTERING; HYDROCARBONS; MEV RANGE 10-100; MEV RANGE 100-1000; OPTICAL THEOREM; OXYGEN 16 TARGET; OXYGEN 18 TARGET; PLASTIC SCINTILLATION DETECTOR
- Descriptors DEC
- ANTINUCLEON REACTIONS; BARYON REACTIONS; CROSS SECTIONS; ENERGY RANGE; HADRON REACTIONS; MEASURING INSTRUMENTS; MEV RANGE; NUCLEAR REACTIONS; NUCLEON REACTIONS; ORGANIC COMPOUNDS; RADIATION DETECTORS; SCATTERING; SCINTILLATION COUNTERS; SOLID SCINTILLATION DETECTORS; TARGETS