TY - JOUR
T1 - Isgur-Karl model revisited
AU - Galeta, Leonardo
AU - Pirjol, Dan
AU - Schat, Carlos
PY - 2009/12/23
Y1 - 2009/12/23
N2 - 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.
AB - 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.
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U2 - 10.1103/PhysRevD.80.116004
DO - 10.1103/PhysRevD.80.116004
M3 - Article
AN - SCOPUS:73449124054
SN - 1550-7998
VL - 80
JO - Physical Review D - Particles, Fields, Gravitation and Cosmology
JF - Physical Review D - Particles, Fields, Gravitation and Cosmology
IS - 11
M1 - 116004
ER -