TY - JOUR
T1 - Hybrid baryons in large-Nc QCD
AU - Chow, Chi Keung
AU - Pirjol, Dan
AU - Yan, Tung Mow
PY - 1999/3/1
Y1 - 1999/3/1
N2 - We study the properties and couplings of hybrid baryons in the large-Nc expansion. These are color-neutral baryon states which contain in addition to Nc quarks also one constituent gluon. Hybrid baryons with both symmetric and mixed symmetric orbital wave functions are considered. We introduce a Hartree description for these states, similar to the one used by Witten for ordinary baryons. It is shown that the Hartree equations for Nc, (Nc-1) quarks for symmetric (mixed symmetric) states in hybrid baryons coincide with those in ordinary baryons in the large-Nc limit. The energy due to the gluon field is of order N0cΛQCD and can be interpreted as the mass of a constituent gluon. Under the assumption of color confinement, our results prove the existence of hybrid baryons made up of heavy quarks in the large Nc limit and provide a justification for the constituent gluon picture of these states. The couplings of the hybrid baryons to mesons of arbitrary spin are computed in the quark model. Using constraints from the large Nc scaling laws for the meson-baryon scattering amplitudes, we write down consistency conditions for the meson couplings of the hybrid baryons. These consistency conditions are solved explicitly with results in agreement with those in the quark model for the respective couplings.
AB - We study the properties and couplings of hybrid baryons in the large-Nc expansion. These are color-neutral baryon states which contain in addition to Nc quarks also one constituent gluon. Hybrid baryons with both symmetric and mixed symmetric orbital wave functions are considered. We introduce a Hartree description for these states, similar to the one used by Witten for ordinary baryons. It is shown that the Hartree equations for Nc, (Nc-1) quarks for symmetric (mixed symmetric) states in hybrid baryons coincide with those in ordinary baryons in the large-Nc limit. The energy due to the gluon field is of order N0cΛQCD and can be interpreted as the mass of a constituent gluon. Under the assumption of color confinement, our results prove the existence of hybrid baryons made up of heavy quarks in the large Nc limit and provide a justification for the constituent gluon picture of these states. The couplings of the hybrid baryons to mesons of arbitrary spin are computed in the quark model. Using constraints from the large Nc scaling laws for the meson-baryon scattering amplitudes, we write down consistency conditions for the meson couplings of the hybrid baryons. These consistency conditions are solved explicitly with results in agreement with those in the quark model for the respective couplings.
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U2 - 10.1103/PhysRevD.59.056002
DO - 10.1103/PhysRevD.59.056002
M3 - Article
AN - SCOPUS:17144419273
SN - 0556-2821
VL - 59
SP - 1
EP - 12
JO - Physical Review D - Particles, Fields, Gravitation and Cosmology
JF - Physical Review D - Particles, Fields, Gravitation and Cosmology
IS - 5
M1 - 056002
ER -