Pentaquark decay is suppressed by chirality conservation

It is shown that, if the pentaquark \(\Theta ^ + = uudd\bar s\) baryon can be represented by the local quark current η_Θ, its decay Θ⁺→nK⁺(pK⁰) is forbidden in the limit of chirality conservation. The Θ⁺ decay width Γ is proportional to \(\alpha _s^2 \left\langle {0\left| {\bar qq} \right|0} \right\rangle ^2\), where \(\left\langle {0\left| {\bar qq} \right|0} \right\rangle ,q = u,d,s\), is quark condensate, and, therefore, is strongly suppressed. The polarization operator of the pentaquark current is calculated using the operator product expansion. The Θ⁺ mass found by the QCD sum rules method is in reasonable agreement with experiment.