info:eu-repo/semantics/article
Isgur-Karl model revisited
Fecha
2009-12Registro en:
Galeta, Leonardo Javier; Pirjol, Dan; Schat, Carlos Luis; Isgur-Karl model revisited; American Physical Society; Physical Review D: Particles, Fields, Gravitation and Cosmology; 80; 11; 12-2009; 1160041-1160049
1550-7998
CONICET Digital
CONICET
Autor
Galeta, Leonardo Javier
Pirjol, Dan
Schat, Carlos Luis
Resumen
We show how to match the Isgur-Karl model to the spin-flavor quark operator expansion used in the 1/Nc studies of the nonstrange negative parity L=1 excited baryons. Using the transformation properties of states and interactions under the permutation group S3 we are able to express the operator coefficients as overlap integrals, without making any assumption on the spatial dependence of the quark wave functions. The general mass operator leads to parameter free mass relations and constraints on the mixing angles that are valid beyond the usual harmonic oscillator approximation. The Isgur-Karl model with harmonic oscillator wave functions provides a simple counterexample that demonstrates explicitly that the alternative operator basis for the 1/Nc expansion for excited baryons recently proposed by Matagne and Stancu is incomplete. © 2009 The American Physical Society.