Vector transition form factors of the N K* -> Theta(+) and N (K)over-bar* -> Sigma((10)over-bar)*(-) in the SU(3) chiral quark-soliton model

摘要

We investigate the vector transition form factors of the nucleon and vector meson K* to the pentaquark baryon Theta(+) within the framework of the SU(3) chiral quark-soliton model. We take into account the rotational 1/N-c and linear m(s) corrections, assuming isospin symmetry and employing the symmetry-conserving quantization. It turns out that the leading-order contributions to the form factors are almost cancelled by the rotational corrections. Because of this, the flavor SU(3) symmetry-breaking terms yield sizeable effects on the vector transition form factors. In particular, the main contribution to the electric-like transition form factor comes from the wave-function corrections, which is a consequence of the generalized Ademollo-Gatto theorem derived in the present work. We estimate with the help of the vector meson dominance the K* vector and tensor coupling constants for the Theta(+): g(K*N Theta) = 0.74-0.87 and f(K*N Theta) = 0.53-1.16. We argue that the outcome of the present work is consistent with the null results of the CLAS experiments in the reactions gamma n -> K-Theta(+) and gamma p -> (K) over bar (0)Theta(+). The results of the present work are also consistent with the recent experiments at KEK. In addition, we present the results of the Sigma((10) over bar) -> N (K) over bar* transition form factors and its (K) over bar* N Sigma((10) over bar) coupling constants.