Operator analysis of effective spin-flavor interactions for L=1 excited baryons

We match the nonrelativistic quark model, with both flavor-dependent and flavor-independent effective quark-quark interactions, to the spin-flavor operator basis of the 1=Nc expansion for the L ¼ 1 nonstrange baryons. We obtain analytic expressions for the coefficients of the 1=Nc operators in terms...

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Detalles Bibliográficos
Autores: Willemyns, Cintia Teresita, Schat, Carlos Luis
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2016
País:Argentina
Institución:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/46678
Acceso en línea:http://hdl.handle.net/11336/46678
Access Level:acceso abierto
Palabra clave:Effective Models in Qcd
1/Nc Expansion
Excited Baryons
Quark Model
https://purl.org/becyt/ford/1.3
https://purl.org/becyt/ford/1
Descripción
Sumario:We match the nonrelativistic quark model, with both flavor-dependent and flavor-independent effective quark-quark interactions, to the spin-flavor operator basis of the 1=Nc expansion for the L ¼ 1 nonstrange baryons. We obtain analytic expressions for the coefficients of the 1=Nc operators in terms of radial integrals that depend on the shape and relative strength of the spin-spin, spin-orbit and tensor interactions of the model, which are left unspecified. We obtain several new, parameter-free relations between the seven masses and the two mixing angles that can discriminate between different spin-flavor structures of the effective quark-quark interaction. We discuss in detail how a general parametrization of the mass matrix depends on the mixing angles and is constrained by the assumptions on the effective quark-quark interaction. We find that, within the present experimental uncertainties, consistency with the best values of the mixing angles as determined by a recent global fit to masses and decays does not exclude any of the two most extreme possibilities of flavor-dependent (-independent) quark-quark interactions, as generated by meson (gluon) exchange interactions.