Chiral perturbation theory for pentaquark baryons and its applications

摘要

We construct a chiral Lagrangian for pentaquark baryons assuming that the recently found Theta(+)(1540) state belongs to an antidecuplet of SU(3) flavor symmetry with J(P) = 1/2 +/-. We derive the Gell-Mann-Okubo formulae for the antidecuplet baryon masses, and a possible mixing between the antidecuplet and the pentaquark octet. Then we calculate the cross sections for pi(-) p -> K(-)Theta(+) and gamma n -> K- Theta(+) using our chiral Lagrangian. The resulting amplitudes respect the underlying chiral symmetry of QCD correctly. We also describe how to include the light vector mesons in the chiral Lagrangian. (c) 2005 Elsevier B.V. All rights reserved.