Quark mass dependence of s-wave baryon resonances

C Garcı́A-Recio,M.F.M Lutz,J Nieves

doi:10.1016/j.physletb.2003.11.073

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−.

Highlights

The question what is the true nature of baryon resonances has attracted considerable attention in recent modern constructions of effective field theories describing meson-baryon scattering
Of particular interest is the S(Strangeness) = −2 sector where we find a narrow state with a strong coupling to K Σ suggesting the identification with the three star resonance Ξ(1690)
In the S = −2 sector, we find, besides the resonance which we identify to the Ξ(1690) and mentioned above, a resonance with the same features as that described in [12], which can be identified with the one star Ξ(1620) resonance

Summary

We study the quark mass dependence of JP

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−. PACS numbers: 11.10.St;11.30.Rd;14.20.Gk;14.20.Jn arXiv:nucl-th/0305100v3 16 Dec 2003

INTRODUCTION

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RESULTS AND CONCLUDING