Vector transition form factors of the NK∗→Θ+ and in the SU(3) chiral quark–soliton model

We investigate the vector transition form factors of the nucleon and vector meson K∗ to the pentaquark baryon Θ+ within the framework of the SU(3) chiral quark–soliton model. We take into account the rotational 1/Nc and linear ms 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 Θ+: gK∗NΘ=0.74–0.87 and fK∗NΘ=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 γn→K−Θ+ and . The results of the present work are also consistent with the recent experiments at KEK. In addition, we present the results of the transition form factors and its coupling constants.