Diffractive dissociation process. pi. /sup -/p. -->. pi. /sup -/ (. pi. /sup -/. pi. /sup +/p) at 14 GeV/c. [Cross sections, Deck effect, t- and s-channel helicity conservation]

Technical Report · Sun May 01 04:00:00 EDT 1977

DOI:https://doi.org/10.2172/7211678· OSTI ID:7211678

Rosenfeld, C

An experiment in which a 14 GeV/c ..pi../sup -/ beam was incident on a hydrogen bubble chamber is described. Fast forward scattered pions traversed a wire spark chamber spectrometer downstream of the bubble chamber. Events identified as inelastic by the spectrometer induced a trigger of the bubble chamber camera. The film produced contained a heavy enrichment of events of proton diffractive dissociation. A sample from this exposure of 4400 events of the reaction ..pi../sup -/p ..-->.. ..pi../sup -/N* ..-->.. ..pi../sup -/..pi../sup -/..pi../sup +/p was studied. In the two body mass spectra the only noteworthy feature is the ..delta../sup + +/(1230). In the N* mass spectrum one observes enhancements at 1.49 GeV, 1.72 GeV, and 2.0 GeV. For the prominent 1.72 GeV feature estimates are given of the width and cross section as well as evidence favoring a substantial branching fraction to ..pi delta..(1230). We looked for production of N*(1470) followed by decay to ..pi delta..(1230) with negative result. An examination of the ..delta../sup + +/(1230) decay distribution suggests that the Deck mechanism is the major contributor to the ..pi delta.. subchannel. The s-channel and t-channel helicity conservation rules were tested. One observed violent conflict with sCHC and mild conflict with tCHC. One also tested for simultaneous validity of tCHC and the Gribov--Morrison rule and found no significant contradiction with this dual hypothesis.

• Research Organization: California Univ., Berkeley (USA). Lawrence Berkeley Lab.
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 7211678
• Report Number(s): LBL-6460
• Country of Publication: United States
• Language: English

Related Subjects

645206* -- High Energy Physics-- Particle Interactions & Properties-Theoretical-- Strong Interactions
Baryon No. = 1-- (-1987)
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
BARYON RESONANCES
BARYONS
BOSONS
DECAY
DECK EFFECT
DELTA-1236 RESONANCES
DIFFRACTION MODELS
ELEMENTARY PARTICLES
ENERGY RANGE
FERMIONS
GEV RANGE
GEV RANGE 10-100
HADRON-HADRON INTERACTIONS
HADRONS
INTERACTIONS
LINEAR MOMENTUM
MATHEMATICAL MODELS
MESON-BARYON INTERACTIONS
MESON-NUCLEON INTERACTIONS
MESONS
N RESONANCES
N)RESONANCES
PARTICLE INTERACTIONS
PARTICLE MODELS
PARTICLE PRODUCTION
PARTICLE PROPERTIES
PARTICLE WIDTHS
PION MINUS-PROTON INTERACTIONS
PION-NUCLEON INTERACTIONS
PION-PROTON INTERACTIONS
PIONS
PSEUDOSCALAR MESONS
RESONANCE PARTICLES