| Autor: |
Bruno Julia-Diaz, D.O. Riska |
| Rok vydání: |
2005 |
| Předmět: |
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| Zdroj: |
Nuclear Physics A. 757:441-455 |
| ISSN: |
0375-9474 |
| DOI: |
10.1016/j.nuclphysa.2005.04.008 |
| Popis: |
The Δ – N electromagnetic transition form factors are calculated in a schematic Poincare covariant quark model in three forms of relativistic kinematics. Addition of D-state components to pure S-state model wave functions, chosen so as to reproduce the empirical elastic electromagnetic nucleon form factors with single constituent currents, brings the calculated R EM ratio for the Δ ( 1232 ) → N γ transition closer to the empirical values in instant and point form kinematics. The calculated R SM ratio is insensitive to the D-state component. In front form kinematics the substantial violation of the angular condition for the spin 3 / 2 resonance transition amplitude in the impulse approximation prevents a unique determination of R EM and R SM , both of which are very sensitive to D-state components. In no form of kinematics do D-state deformations of the rest frame baryon wave functions alone suffice for a description of the empirical values of these ratios. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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