Investigation For Electromagnetic Form Factors Dipole Formulas Of The Octet Strange Baryons

As fundamental parameters for the internal structure of a particle, the electromagnetic form factors play a key role in the investigation for the internal dynamics of the particle. As shown by the early experiments, electromagnetic form factors of nucleons which depend on momentum transfer can be well characterized by the dipole formula; the possible origin for this dipole formula has been interpreted in the framework of vector meson dominance model (VMD) theoretically. Due to the SU(3) flavor symmetry for octet strange baryons and nucleons, people consider that octet strange baryons have the same physics mechanism as nucleons on electromagnetic quality, and they extract the magnetic moments by the simulation for dipole formulas. While the dipole formulas for octet baryons have not been testified. In addition, the measurement for the charge radius ofΣ? makes it possible to study the electromagnetic structure of strange baryons in experiment. Therefore, the investigations for electromagnetic form factors dipole formulas of octet strange baryons not only have important significance in theory, but also get close to the evolution of experiments.In this thesis, the electromagnetic form factors of the octet strange baryons are examined to verify the assumption that these hadrons have the similar dipole character as the case of the nucleons. We make a summary of the nucleon electromagnetic form factors, and give a detailed introduction of the vector meson dominance model. Starting from the origin of the nucleon electromagnetic form factors dipole formula, the investigation has been carried out in the hadronic level with some models which are pertinent to the electromagnetic characteristics of the baryons. We have fixed the vector mesons which play dominant roles for electromagnetic form factors of different octet strange baryons, and then the formulas which depend on the momentum transfer for these form factors have been obtained. Our results show that, the electromagnetic form factors of the octet strange baryons can be well described by the dipole formulas at low momentum transfer, whereas deviate from the dipole formulas at high momentum transfer due to the different masses between the dominated vector mesons. As an application of the above formulas, the charge and magnetic radii of the related baryons have been evaluated, which are in accordance with the existing data.