pi. N S/sub 11/ partial-wave amplitude near the etan production threshold. [Cusp size and orientation, partial wave unitarity]

Journal Article · Sat Jan 01 04:00:00 EST 1977 · Phys. Rev., D; (United States)

DOI:https://doi.org/10.1103/PhysRevD.15.192· OSTI ID:7333760

Bhandari, R; Chao, Y

From an analysis of the ..pi../sup -/p backward differential cross-section data, which clearly shows a cusplike structure near the etan threshold, we deduce, using partial-wave unitarity relations, the size and the orientation of the cusp. The cusp appears because of the strong coupling of the etan channel to an N' resonance just above its threshold. Using the above information on the cusp, the ..pi..N S/sub 11/ partial-wave amplitude is fitted through the etan threshold and the resonance. The effect of the size of the cusp, acting as a constraint, on the resonance parameters determined in the fit is emphasized. The fit also determines the phase of the etaN production amplitude at the etan threshold, which then using the knowledge of the orientation of the cusp gives information on the phase of the elastic no-spin-flip amplitude at the etan threshold. This information could be a useful constraint in ..pi..N partial-wave analysis. (AIP)

• Research Organization: Department of Physics, Carnegie-Mellon University Pittsubrgh, Pennsylvania 15213
• OSTI ID: 7333760
• Journal Information: Phys. Rev., D; (United States), Journal Name: Phys. Rev., D; (United States) Vol. 15:1; ISSN PRVDA
• Country of Publication: United States
• Language: English

Related Subjects

645205* -- High Energy Physics-- Particle Interactions & Properties-Theoretical-- Strong Interactions
Baryon No. = 0-- (-1987)
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
AMPLITUDES
ANGULAR MOMENTUM
BARYONS
BOSONS
BRANCHING RATIO
CROSS SECTIONS
DIFFERENTIAL CROSS SECTIONS
ELASTIC SCATTERING
ELEMENTARY PARTICLES
ENERGY
ETA MESONS
FERMIONS
HADRON-HADRON INTERACTIONS
HADRONS
INELASTIC SCATTERING
INTERACTIONS
MESON-BARYON INTERACTIONS
MESON-NUCLEON INTERACTIONS
MESONS
NEUTRONS
NUCLEONS
PARTICLE INTERACTIONS
PARTICLE PRODUCTION
PION MINUS-PROTON INTERACTIONS
PION-NUCLEON INTERACTIONS
PION-PROTON INTERACTIONS
PSEUDOSCALAR MESONS
RESONANCE SCATTERING
SCATTERING
SCATTERING AMPLITUDES
SPIN FLIP
THRESHOLD ENERGY