Pion charge radius and the pion form factor
The pion charge-form factor data for positive and negative values of k/sup 2/, the P-wave ..pi..-..pi.. phase-shift data, and the pion charge-radius data are analyzed using form factors previously developed by us and other authors. The peaked behavior near threshold for the P-wave ..pi..-..pi.. phase shift suggested by Levin and Okubo is found not to be necessary for large charge-radius values, but larger slopes (ddelta/sub 11//dk/sup 2/) at threshold do seem to be the important factor. We conclude that a more precise measurement of the pion charge radius is necessary to separate the different theoretical models. We also find that the form-factor data near (timelike) k/sup 2/ approx. - 1.51 (GeV/c)/sup 2/ are sufficiently imprecise that nothing definitive can be said about the existence of the rho' resonance. If such a resonance exists and if the pion has no hard core, the data are either consistent with a rho' resonance of width GAMMA/sub rho prime/ approx. 2 MeV or consistent with a rho' resonance of large width if at least one additional rho' resonance, rho'', exists.
- Research Organization:
- Ames Laboratory-ERDA and Department of Physics, Iowa State University, Ames, Iowa 50011
- OSTI ID:
- 7312186
- Journal Information:
- Phys. Rev., D; (United States), Vol. 15:3
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
PION-PION INTERACTIONS
PHASE SHIFT
RHO-1250 RESONANCES
PARTICLE WIDTHS
CHARGE DISTRIBUTION
FORM FACTORS
P WAVES
PIONS
RESONANCE
SCATTERING AMPLITUDES
THRESHOLD ENERGY
AMPLITUDES
BOSONS
ELEMENTARY PARTICLES
ENERGY
EXOTIC RESONANCES
HADRON-HADRON INTERACTIONS
HADRONS
INTERACTIONS
MESON RESONANCES
MESON-MESON INTERACTIONS
MESONS
PARTIAL WAVES
PARTICLE INTERACTIONS
PARTICLE PROPERTIES
PSEUDOSCALAR MESONS
RESONANCE PARTICLES
645205* - High Energy Physics- Particle Interactions & Properties-Theoretical- Strong Interactions
Baryon No. = 0- (-1987)