Measurement of the near-threshold H(π+,π+ π+)n cross section and chiral symmetry

• Published in: Physical review letters 1991-05, Vol.66 (20), p.2569-2572
• Main Authors: SEVIOR, M. E, AMBARDAR, A, MEIRAV, O, OTTEWELL, D. F, RUI, R, SMITH, G. R, SOSSI, V, THEIS, D, VETTERLI, D, BRACK, J. T, CAMERINI, P, DUNCAN, F, ERNST, J, FELTHAM, A, GRION, N, JOHNSON, R. R, KOCH, G
• Format: Article
• Language: English
• Subjects: 645103 > High Energy Physics-- Particle Interactions & Properties-Experimental-- Strong Interactions & Baryon & Meson Properties; 645300 > High Energy Physics-- Particle Invariance Principles & Symmetries; AMPLITUDES; CHARGED-PARTICLE REACTIONS; CHIRAL SYMMETRY; CROSS SECTIONS; DATA; DIMENSIONS; ENERGY RANGE; Exact sciences and technology; EXPERIMENTAL DATA; HADRON REACTIONS; HADRON-HADRON INTERACTIONS; Hadron-induced low- and intermediate-energy reactions and scattering (energy ≤ 10 gev); HYDROGEN 1 TARGET; INELASTIC SCATTERING; INFORMATION; INTERACTIONS; LENGTH; MATRIX ELEMENTS; MESON REACTIONS; MESON-MESON INTERACTIONS; MEV RANGE; MEV RANGE 10-100; MEV RANGE 100-1000; MONTE CARLO METHOD; NUCLEAR PHYSICS AND RADIATION PHYSICS; NUCLEAR REACTIONS; NUMERICAL DATA; PARTICLE INTERACTIONS; Physics; PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; PION PLUS REACTIONS; PION REACTIONS; PION-PION INTERACTIONS; SCATTERING; SCATTERING AMPLITUDES; SCATTERING LENGTHS; Specific reactions and phenomenology; SYMMETRY; TARGETS 651220 > Nuclear Properties & Reactions, A=1-5, Experimental; The physics of elementary particles and fields; TOTAL CROSS SECTIONS
• ISSN: 0031-9007; 1079-7114
• DOI: 10.1103/PhysRevLett.66.2569

Total cross sections for the H({pi}{sup +},{pi}{sup +}{pi}{sup +}){ital n} reaction have been measured at pion kinetic energies of 180, 184, 190 and 200 MeV. The threshold value for the matrix element {ital a}({pi}{sup +}{pi}{sup +}) and the {ital s}-wave, isospin-2, {pi}{pi} scattering length {ital a}{sub 2}{sup 0} were determined. The results were found to be in agreement with chiral perturbation theory and inconsistent with the model of dominance by quark loop anomalies.