Production of three charged pions in pi minus proton interactions at 5 Bev/c

"The 72"" Bubble Chamber at the Lawrence Radiation Laboratory has been exposed to a beam of 5 Bev/c pi- mesons and 150,000 photographs have been taken. As a part of this experiment, the interactions producing four charged particles in the final states have been measured and the reaction pi-p -> ppi+pi-pi- has been studied, with the emphasis placed on the three pions system. The cross section for this reaction was found to be 1.80±0.45 mba For the final analysis 6300 events (.286 ± .071 pb/event) were selected. The mass spectra of the different particle combinations have been investigated. The reaction has been found to be characterized by the following features: (1) Strong production of well-known resonances, in particular the p (35% of the events), N1236 (30%) and various N IS. (2) A broad enhancement in the pi+pi-pi- and in the popi mass between 1.0 and 1.4 Bev, associated wllh momentum transfers to the proton characteristic of diffraction-scattering. The data below the A2 mass (1.26 Bev) are consistent with this enhancement being a state of spinparity I+ with J = 0 along the incident pion direction. It does not z appear to be entirely due to a Deck-type kinematic effect. (3) Three peaks of marginal statistical significance in the pi+pi-pi- mass, with masses (and widths) 1.06 Bev (40 Mev), 1.17 Bev (60 Mev) and 1.475 Bev (30 Mev). (4) Peripheral production of a meson of mass 1.62 Bev, width about 100 Mev, decaying into pi+pi-pi-,and known as the A3 meson. Its spin-parity is most probably 2-."

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physics

Year dc:date

2011

Author dc:creator

• Terreault, Bernard

Contributors dc:contributor

• Kruse, U.E.

• charged pions
• pi proton interactions
• hydrogen bubble chamber

Statement dc:rights

• 1969 Bernard Terreault

Language dc:language

en

Identifier

6066114

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/25776