Pentaquarks in the Jaffe–Wilczek Approximation.

The masses of uudds, uuddd, and uussd pentaquarks are evaluated in a framework of both the effective Hamiltonian approach to QCD and the spinless Salpeter equation using the Jaffe–Wilczek diquark approximation and the string interaction for the diquark–diquark–antiquark system. The pentaquark masses are found to be in the region above 2 GeV. That indicates that the Goldstone boson exchange effects may play an important role in the light pentaquarks. The same calculations yield the mass of [ud]2c pentaquark ∼3250 MeV and [ud]2b pentaquark ∼6509 MeV.© 2005 Pleiades Publishing, Inc. [ABSTRACT FROM AUTHOR]