Effective theory approach to the skyrme model and application to pentaquarks

The Skyrme model is reconsidered from an effective theory point of view. From the most general chiral Lagrangian up to and including terms of order p⁴, N_c and δm² (δm ≡ m _s - m), new interactions, which have not been previously considered, appear upon collective coordinate quantization. We obtain the parameter set that best fits the observed low-lying baryon masses by carrying out second-order perturbative calculations with respect to δm. We calculate the masses and the decay widths of the other members of (mainly) anti-decuplet pentaquark states. The formula for the decay widths is reconsidered, and its baryon mass dependence is clarified.