Study of the reactions. pi. +p. --> pi. /sup +/p. pi. /sup 0//sub fast/ and. pi. /sup +/p. --> pi. /sup +/n. pi. /sup +/. pi. /sup 0//sub fast/ at 15. 7 GeV/c

Thesis/Dissertation · Thu Dec 31 23:00:00 EST 1981

OSTI ID:5210849

Glanzman, T L

The reactions ..pi../sup +/p..--> pi../sup +/p..pi..O and ..pi.. + p..--> pi.. + n..pi..=..pi../sup 0/ are studied at 15.7 GeV/c using the SLAC 1 meter Hybrid Bubble Chamber facility with the addition of a large lead glass photon detector. The 677,000 pictures taken represent a 22.8 event/..mu..b untriggered sensitivity. The present analysis consists of 38,900 2-prong events with an identified and fully measured ..pi../sup 0/. Systematics for incorporating lead gas data for neutral particles with charged particle information from the bubble chamber are developed. Several resonance channels in the ..pi../sup +/p..pi../sup 0/ final state are observed. Isolation of the ..pi../sup +/p..--> delta../sup + +/..pi../sup 0/ events yielded a production cross section of (32.6 +/- 3.5) ..mu..b. The production mechanism for the ..delta../sup + +/, as studied through the spin density matrix elements and t-distribution, is found to be in good agreement with the Regge Pole Model. The appearance of dual solutions for the Regge amplitudes does not rule out a photon-like rho meson (helicity = +/- 1) mediating this reaction. Production of the rho/sup +/ meson in the reaction ..pi../sup +/p..-->..p/sup +/rho is observed with a cross section of (20.6 +/- 7.4) ..mu..b. An analysis of the spin density matrix elements indicates an approximately equal contribution of ..pi.. and ..omega.. exchange mediating p/sup +/ production. The reaction ..pi../sup +/p..-->..g/sup +/(1700)p is seen with a partial cross section of (3.2 +/- 1.1) ..mu..b for ..pi.. + ..pi../sup 0/ decays with a forward ..pi../sup 0/. No other resonance behavior with a cross section greater than 1.4 ..mu..b/0.2 GeV/c/sup 2/ is observed in this system above a mass of 1.8 GeV/c/sup 2/. The first study of the reaction ..pi../sup +/p..-->.. rho /sup +/..pi../sup +/n was made in this experiment and found to have a cross section of (90.2 +/- 10.6) ..mu..b. The spin density matrix elements are fitted, and exchange properties of this reaction studied. This reaction is seen to favor ..pi..-exchange as the dominant production process.

• Research Organization: Duke Univ., Durham, NC (USA)
• OSTI ID: 5210849
• Country of Publication: United States
• Language: English

Related Subjects

645104* -- High Energy Physics-- Particle Interactions & Properties-Experimental-- Strong Meson-Induced Interactions-- (-1987)
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ACCELERATORS
BARYONS
BOSONS
CROSS SECTIONS
DATA
DECAY
DENSITY MATRIX
ELEMENTARY PARTICLES
ENERGY RANGE
EXCHANGE INTERACTIONS
EXPERIMENTAL DATA
FERMIONS
GEV RANGE
GEV RANGE 10-100
HADRON-HADRON INTERACTIONS
HADRONS
INFORMATION
INTERACTIONS
LINEAR ACCELERATORS
MATRICES
MESON-BARYON INTERACTIONS
MESON-NUCLEON INTERACTIONS
MESONS
NEUTRONS
NUCLEONS
NUMERICAL DATA
PARTICLE DECAY
PARTICLE INTERACTIONS
PARTICLE PRODUCTION
PION PLUS-PROTON INTERACTIONS
PION-NUCLEON INTERACTIONS
PION-PROTON INTERACTIONS
PIONS
PIONS NEUTRAL
PIONS PLUS
PROTONS
PSEUDOSCALAR MESONS
REGGE POLES
RESONANCE PARTICLES
STANFORD 20-GEV LINAC