Anti-decuplet pentaquarks in the chiral quark-soliton model

This thesis is an investigation of the anti-decuplet pentaquarks, especially the Θ+(udd anti s), within the framework of the χQSM. All baryon properties in this work are calculated by diagonalizing the χQSM Hamiltonian numerically and using these eigenvalues. Using the explicit dynamics of the χQSMenables us to investigate systematically properties of the octet, decuplet and anti-decuplet baryons, all of them within the same set of parameters. The χQSM is in good agreement with octet experimental data and since the new pentaquark discussion was triggered by the rotational picture of the χQSM, it is natural to extend this formalism to the anti-decuplet. At first we extract the mass of the Θ+ in the χQSM. Among the results in this work, there are two of greater interest. In the light of the unsettled experimental situation the production/ formation of the Θ+ plays an outstanding role. These processes are characterized by the coupling constants of the vector kaon and pseudo-scalar kaon coupling to the Θ-N system. In order to be compatible with experiments these coupling constants should be small. The vector kaon coupling strength can be extracted out of the vector-current via the vector-meson dominance. The vector-current will be subject of the third chapter. The pseudo-scalar kaon coupling is discussed in the fourth chapter along with the axial-vector current. By mapping the axial-vector constant to the strong coupling via the Goldberger-Treiman relation we are able to determine the Θ+ decay width. Further aspects in case of the vector-current are the spatial sizes of the Θ+. We will determine the electric radii of the anti-decuplet baryons in order to distinguish whether the Θ+, minimal Fockcomponent of a five-quark state, is some kind of N-K molecule or a compact object like normal baryons. Magnetic anti-decuplet form factors are presented. Magnetic moments are also calculated for decuplet baryons. We consider the symmetry conserving quantization in the axial-vector current which has a sizeable impact on the Θ+ decay width. Axial-vector form factors of the anti-decuplet and constants in case of the decuplet baryons are given. Semi-leptonic octet decays with SU(3)-symmetry breaking effects and the symmetry conserving quantization are calculated. We apply the symmetry conserving quantization to the nucleon tensor charges. The nucleon tensor form factors are considered for the first time up to a momentum transfer of Q2 ≤ 1GeV2 in the χQSM. Necessary analytical and numerical steps for the tensor form factors in the χQSM are presented. (orig.)