TY - JOUR
T1 - 1/Nc expansion and the spin-flavor structure of the quark interaction in the constituent quark model
AU - Pirjol, Dan
AU - Schat, Carlos
PY - 2010/12/6
Y1 - 2010/12/6
N2 - We study the hierarchy of the coefficients in the 1/Nc expansion for the negative parity L=1 excited baryons from the perspective of the constituent quark model. This is related to the problem of determining the spin-flavor structure of the quark interaction. The most general two-body scalar interaction between quarks contains the spin-flavor structures t1at2a,s →1•s→2 and s→1•s →2t1at2a. We show that in the limit of a zero range interaction all these structures are matched onto the same hadronic mass operator Sc2, which gives a possible explanation for the dominance of this operator in the 1/N c expansion for the L=1 states and implies that in this limit it is impossible to distinguish between these different spin-flavor structures. Modeling a finite range interaction through the exchange of a vector and pseudoscalar meson, we propose a test for the spin-flavor dependence of the quark forces. For the scalar part of the quark interaction, we find that both pion exchange and gluon exchange are compatible with the data.
AB - We study the hierarchy of the coefficients in the 1/Nc expansion for the negative parity L=1 excited baryons from the perspective of the constituent quark model. This is related to the problem of determining the spin-flavor structure of the quark interaction. The most general two-body scalar interaction between quarks contains the spin-flavor structures t1at2a,s →1•s→2 and s→1•s →2t1at2a. We show that in the limit of a zero range interaction all these structures are matched onto the same hadronic mass operator Sc2, which gives a possible explanation for the dominance of this operator in the 1/N c expansion for the L=1 states and implies that in this limit it is impossible to distinguish between these different spin-flavor structures. Modeling a finite range interaction through the exchange of a vector and pseudoscalar meson, we propose a test for the spin-flavor dependence of the quark forces. For the scalar part of the quark interaction, we find that both pion exchange and gluon exchange are compatible with the data.
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U2 - 10.1103/PhysRevD.82.114005
DO - 10.1103/PhysRevD.82.114005
M3 - Article
AN - SCOPUS:78651338282
SN - 1550-7998
VL - 82
JO - Physical Review D - Particles, Fields, Gravitation and Cosmology
JF - Physical Review D - Particles, Fields, Gravitation and Cosmology
IS - 11
M1 - 114005
ER -