Vector transition form factors of the $N{K}^{\ast }\to {\Theta }^{+}$ and $N{\bar{K}}^{\ast }\to {\Sigma }_{\overline{10}}^{\ast -}$ in the SU(3) chiral quark-soliton model

Abstract

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 $m_{\mathrm{s}}$ 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^+: $g_{K^{\ast }N\Theta }=0.74-0.87$ and $f_{K^{\ast }N\Theta }=0.53-1.16$. 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 ->bar{K}^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 ${\Sigma }_{\overline{10}}\to N{\bar{K}}^{\ast }$ transition form factors and its ${\bar{K}}^{\ast }N{\Sigma }_{\overline{10}}$ coupling constants.

26 pages, 10 figures

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• Measurement of eta photoproduction on the proton from threshold to 1500 MeV
• Measurement of the beam asymmetry in eta-photoproduction off the proton
• Photoproduction of eta-mesons on the deuteron above S11(1535) in the presence of a narrow P11(1670) resonance
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Cited by in corpus (1)

• Baryon vector and axial content up to the 7Q component