Pentaquark decay width in QCD sum rules

In a diquark-diquark-antiquark picture of the pentaquark we study the decay $\ensuremath{\Theta}\ensuremath{\rightarrow}{K}^{+}n$ within the framework of QCD sum rules. After evaluation of the relevant three-point function, we extract the coupling ${g}_{\ensuremath{\Theta}nK}$ which is directly related to the pentaquark width. Restricting the decay diagrams to those with color exchange between the mesonlike and baryonlike clusters reduces the coupling constant by a factor of 4. Whereas a small decay width might be possible for a positive parity pentaquark, it seems difficult to explain the measured width for a pentaquark with negative parity.