Pentaquark decay is suppressed by chirality conservation

Abstract

It is shown, that if the pentaquark $Θ^+ = uudd\bar{s}$ baryon can be represented by the local quark current $η_Θ$, its decay $Θ^+ \to n K^+ (p K^0)$ is forbidden in the limit of chirality conservation. The $Θ^+$decay width $Γ$ is proportional to $α^2_s < 0 | \bar{q} q | 0 >^2$, where $<0 | \bar{q} q | 0 >$, $q = u,d,s$ is quark condensate, and, therefore, is strongly suppressed. Also the polarization operator of the pentaquark current with isospin 1 is calculated using the operator product expansion and estimation for it mass is obtained .