Quark mass dependence of s-wave baryon resonances

Abstract

We study the quark mass dependence of JP=1/2− s-wave baryon resonances. Parameter free results are obtained in terms of the leading order chiral Lagrangian. In the ‘heavy’ SU(3) limit with mπ=mK≃500 MeV the resonances turn into bound states forming two octets plus a singlet representations of the SU(3) group. A contrasted result is obtained in the ‘light’ SU(3) limit with mπ=mK≃140 MeV for which no resonances exist. Using physical quark masses our analysis suggests to assign to the S=−2 resonances Ξ(1690) and Ξ(1620) the quantum numbers JP=1/2−.