Low-energy pion-pion scattering and pion electromagnetic vertex functions

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1986

OSTI ID:6316499

Erkal, C

A two-channel N/D method is used to analyze the ..pi pi.. scattering p-wave phase shift and inelasticity data up to 2 GeV c.m. energy. They show that if the inelastic scattering of the pions is represented by the second quasi-two-body channel, a two-channel parameterization with two subtractions provides an excellent representation of the data. In addition, the correct p-wave scattering length is obtained in agreement with dispersive sum rules. The same two-channel model is used to construct 2..pi.. and 4..pi.. electromagnetic form factors. They find that a good representation of the pion form factor can be achieved but only at the expense of the F/sub 4..pi../ form factor. It seems to be difficult to reconcile all of the data in the rho (1600) region within a two resonance framework indicating additional rho-like resonant structure in this energy region. A minimal multichannel N/D model which can describe the pion-pion scattering processes (..pi pi.. ..-->.. ..pi pi.., ..pi../sup 0/omega, 4..pi..) has three channels one of which is nonresonant. N and D are parameterized in the channel space as 3 x 3 matrices. The matrix elements N/sub ij/ and D/sub ij/ are represented by a dispersion relation. The pion form factors and pion-pion elastic scattering amplitude are obtained from the model and compared to the existing data to reveal the resonance structure in the p-wave amplitude up to ..sqrt..s = 2 GeV c.m. energy.

• Research Organization: Wisconsin Univ., Madison (USA)
• OSTI ID: 6316499
• Country of Publication: United States
• Language: English

Related Subjects

645204* -- High Energy Physics-- Particle Interactions & Properties-Theoretical-- Strong Interactions & Properties
653003 -- Nuclear Theory-- Nuclear Reactions & Scattering
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
AMPLITUDES
BOSONS
COUPLED CHANNEL THEORY
DATA
DISPERSION RELATIONS
ELEMENTARY PARTICLES
ENERGY RANGE
FORM FACTORS
FUNCTIONS
GEV RANGE
HADRON-HADRON INTERACTIONS
HADRONS
INFORMATION
INTERACTIONS
MATRIX ELEMENTS
MESON-MESON INTERACTIONS
MESONS
NUMERICAL DATA
PARTICLE INTERACTIONS
PARTICLE PROPERTIES
PHASE SHIFT
PION-PION INTERACTIONS
PIONS
PSEUDOSCALAR MESONS
RESONANCE
RHO-1250 RESONANCES
RHO-1600 RESONANCES
RHO-765 RESONANCES
SCATTERING
SCATTERING AMPLITUDES
THEORETICAL DATA
VERTEX FUNCTIONS