Nucleon polarizabilities and. pi. /sup 0/. -->. 2. gamma. , eta/sup 0/. -->. 2. gamma. decay rates from Compton-scattering amplitudes

Journal Article · Wed Sep 01 00:00:00 EDT 1976 · Phys. Rev., D; (United States)

DOI:https://doi.org/10.1103/PhysRevD.14.1335· OSTI ID:7337021

Guiasu, I; Radescu, E E

The difference of the dynamic electric and magnetic polarizabilities of the nucleon ..cap alpha.. - ..beta.. is estimated on the basis of sum rules obtained from unsubtracted backward dispersion relations for the relevant nucleon Compton-scattering amplitudes in the framework of the two-particle unitarity approximation. The s- and u-channel contributions are then evaluated in terms of pion photoproduction data while the contribution of the two-pion state in the t channel is shown to contain a large positive piece, explicitly computed, which could bring the theoretical prediction into qualitative agreement with the existing experimental results. It is consequently pointed out that, if the ordering ..cap alpha.. > ..beta.. is further confirmed experimentally, the annihilation-channel exchanges should be strongly responsible for this fact. The importance of the two-pion continuum for the dispersion determination of the eta/sup 0/ ..-->.. 2..gamma.. decay rate from the superconvergence of certain nucleon Compton-scattering amplitudes for fixed s and large t is also particularly emphasized. (AIP)

• Research Organization: Institute of Atomic Physics, P.O. Box 5206, Bucharest, Romania
• OSTI ID: 7337021
• Journal Information: Phys. Rev., D; (United States), Vol. 14:5
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
COMPTON EFFECT
SCATTERING AMPLITUDES
ETA MESONS
DECAY
NUCLEONS
POLARIZABILITY
PIONS NEUTRAL
DIFFERENTIAL CROSS SECTIONS
DISPERSION RELATIONS
PHOTON-NUCLEON INTERACTIONS
POLARIZED NUCLEI
S CHANNEL
SPECTRA
SUM RULES
U CHANNEL
UNITARY POLE APPROXIMATION
AMPLITUDES
BARYONS
BASIC INTERACTIONS
BOSONS
CROSS SECTIONS
ELASTIC SCATTERING
ELECTRICAL PROPERTIES
ELECTROMAGNETIC INTERACTIONS
ELEMENTARY PARTICLES
EQUATIONS
FERMIONS
HADRONS
INTERACTIONS
MESONS
NUCLEI
PARTICLE INTERACTIONS
PHOTON-BARYON INTERACTIONS
PHOTON-HADRON INTERACTIONS
PHYSICAL PROPERTIES
PIONS
PSEUDOSCALAR MESONS
SCATTERING
645202* - High Energy Physics- Particle Interactions & Properties-Theoretical- Electromagnetic Interactions & Properties
645206 - High Energy Physics- Particle Interactions & Properties-Theoretical- Strong Interactions
Baryon No. = 1- (-1987)