Dynamical coupled-channels model of {pi}N scattering in the W{<=}2 GeV nucleon resonance region

Journal Article · Sat Dec 15 00:00:00 EST 2007 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.76.065201· OSTI ID:21067999

Julia-Diaz, B ^[1]; Lee, T.-S. H. ^[1]; Matsuyama, A ^[1]; Sato, T ^[1]

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1. Excited Baryon Analysis Center (EBAC), Thomas Jefferson National Accelerator Facility, Newport News, Virginia 22901 (United States)

As a first step to analyze the electromagnetic meson production reactions in the nucleon resonance region, the parameters of the hadronic interactions of a dynamical coupled-channels model, developed in Physics Reports 439, 193 (2007), are determined by fitting the {pi}N-scattering data. The channels included in the calculations are {pi}N,{eta}N, and {pi}{pi}N, which has {pi}{delta},{rho}N, and {sigma}N resonant components. The nonresonant meson-baryon interactions of the model are derived from a set of Lagrangians by using a unitary transformation method. One or two bare excited nucleon states in each of S,P,D, and F partial waves are included to generate the resonant amplitudes in the fits. The parameters of the model are first determined by fitting as much as possible the empirical {pi}N elastic-scattering amplitudes of SAID up to 2 GeV. We then refine and confirm the resulting parameters by directly comparing the predicted differential cross section and target polarization asymmetry with the original data of the elastic {pi}{sup {+-}}p{yields}{pi}{sup {+-}}p and charge-exchange {pi}{sup -}p{yields}{pi}{sup 0}n processes. The predicted total cross sections of {pi}N reactions and {pi}N{yields}{eta}N reactions are also in good agreement with the data. Applications of the constructed model in analyzing the electromagnetic meson production data as well as the future developments are discussed.

• OSTI ID: 21067999
• Journal Information: Physical Review. C, Nuclear Physics, Vol. 76, Issue 6; Other Information: DOI: 10.1103/PhysRevC.76.065201; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ASYMMETRY
CHARGE EXCHANGE
COUPLED CHANNEL THEORY
DIFFERENTIAL CROSS SECTIONS
ELASTIC SCATTERING
ETA MESONS
GEV RANGE
LAGRANGIAN FUNCTION
NUCLEONS
PARTIAL WAVES
PARTICLE PRODUCTION
PION-NUCLEON INTERACTIONS
PIONS MINUS
POLARIZATION
RESONANCE PARTICLES
RHO-770 MESONS
SCATTERING AMPLITUDES
TOTAL CROSS SECTIONS
TRANSFORMATIONS