Masses and Sigma Terms of Pentaquarks in Chiral Perturbation Theory

Assuming that the recently theta(+) and other exotic resonances belong to the pentaquark (1) over bar(0) over bar of SU(3)(f) with J(P) = 1/2, we constructed a relativistic effective lagrangian in the frame work of baryon chiral perturbation theory. The masses of pentaquarks under isospin symmetry is determined by calculating the propagator to one loop, where the extended on-mass-shell renormalization scheme is applied. Using the experimental data for masses of (+theta), Xi and N, we estimated the mass of Sigma and the sigma terms.