Constituent quark model study of light- and strange-baryon spectra

We investigate the structure of the SU(3) octet and decuplet baryons employing a constituent quark model designed for the study of the baryon-baryon interaction and successfully applied to the meson spectra. The model considers through the interacting potential perturbative, one-gluon exchange, and non-perturbative, boson exchanges and confinement, aspects of the underlying theory, QCD. We solve the three-quark problem by means of the Faddeev method in momentum space. We analyze the effect of the different terms in the interaction and make contact with the use of relativistic kinematics. We find an explanation to the strong contribution of the pseudoscalar forces in the semirelativistic approach for the octet baryons. A phenomenological recipe for the regularization parameter of the one-gluon exchange is found.Comment: 17 pages, 6 figures, accepted for publication in Phys. Rev.

Coupled channels calculation of a pion-Lambda-nucleon quasibound state

We extend the study of a JP=2+, I=3/2 pion-Lambda-nucleon quasibound state [Phys. Rev. D 78, 014013 (2008)] by solving nonrelativistic Faddeev equations, using 3S1-3D1, Lambda N - Sigma N coupled channels Chiral Quark Model local interactions, and pion-nucleon and coupled pion-Lambda - pion-Sigma separable interactions fitted to the position and decay parameters of the Delta(1232) and Sigma(1385) resonances, respectively. The results exhibit a strong sensitivity to the p-wave pion-hyperon interaction, with a pion-Lambda-nucleon quasibound state persisting over a wide range of acceptable parametrizations.Comment: references corrected, matches Phys. Rev. C versio

Does the quark cluster model predict any isospin two dibaryon resonance?

We analyze the possible existence of a resonance in the $J^P=0^-$ channel with isospin two by means of nucleon-$\Delta$ interactions based on the constituent quark model. We solve the bound state and the scattering problem using two different potentials, a local and a non-local one. The non-local potential results to be the more attractive, although not enough to generate the experimentally predicted resonance.Comment: 9 pages in Latex (revtex), 2 eps figures available under reques

ndnd scattering lengths from a quark-model based NNNN interaction

We calculate the doublet and quartet neutron-deuteron scattering lengths using a nonlocal nucleon-nucleon interaction fully derived from quark-quark interactions. We use as input the $NN$ $^1S_0$ and $^3S_1$-${}^3 D_1$ partial waves. Our result for the quartet scattering length agrees well with the experimental value while the result for the doublet scattering length does not. However, if we take the result for the doublet scattering length together with the one for the triton binding energy they agree well with the so-called Phillips line.Comment: 6 pages, 2 tables. Accepted for publication in Physical Review