The Lambda(1405) state in a chiral unitary approach with off-shell corrections to dimensional regularized loop functions

The Bethe-Salpeter equation is solved in the framework of unitary coupled-channel approximation by using the pseudoscalar meson-baryon octet interaction. The loop function of the intermediate meson and baryon is deduced in a dimensional regularization scheme, where the relativistic kinetic effect and off-shell corrections are taken into account. According to the experimental data, the subtract constants in the loop function are determined. The squared amplitude is suppressed strongly and only one Lambda(1405) state is generated dynamically in the strangeness S=-1 and isospin I=0 sector.