Pentaquark and diquark–diquark clustering: a QCD sum rule approach

AbstractIn this work we study the Θ+(1540) in the framework of QCD sum rules based on (ud)2s¯ diquark clustering as suggested by Jaffe and Wilczek. Within errors, the mass of the pentaquark is compatible with the experimentally measured value. The mass difference between the Θ+ and the pentaquark with the quantum numbers of the nucleon amounts to 70 MeV, consistent with the interpretation of the N(1440) as a pentaquark