TY - JOUR
T1 - Positive parity pentaquark towers in large Nc QCD
AU - Pirjol, Dan
AU - Schat, Carlos
PY - 2007/4/25
Y1 - 2007/4/25
N2 - We construct the complete set of positive parity pentaquarks, which correspond in the quark model to s̄qNc+1 states with one unit of orbital angular momentum L=1. In the large Nc limit they fall into the K=1/2 and K=3/2 irreps (towers) of the contracted SU(4)c symmetry. We derive predictions for the mass spectrum and the axial couplings of these states at leading order in 1/Nc. The strong decay width of the lowest-lying positive parity exotic state is of order O(1/Nc), such that this state is narrow in the large Nc limit. Replacing the antiquark with a heavy antiquark Q̄qNc+1, the two towers become degenerate, split only by O(1/mQ) hyperfine interactions. We obtain predictions for the strong decay widths of heavy pentaquarks to ordinary baryons and heavy HQ̄(*) mesons at leading order in 1/Nc and 1/mQ.
AB - We construct the complete set of positive parity pentaquarks, which correspond in the quark model to s̄qNc+1 states with one unit of orbital angular momentum L=1. In the large Nc limit they fall into the K=1/2 and K=3/2 irreps (towers) of the contracted SU(4)c symmetry. We derive predictions for the mass spectrum and the axial couplings of these states at leading order in 1/Nc. The strong decay width of the lowest-lying positive parity exotic state is of order O(1/Nc), such that this state is narrow in the large Nc limit. Replacing the antiquark with a heavy antiquark Q̄qNc+1, the two towers become degenerate, split only by O(1/mQ) hyperfine interactions. We obtain predictions for the strong decay widths of heavy pentaquarks to ordinary baryons and heavy HQ̄(*) mesons at leading order in 1/Nc and 1/mQ.
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U2 - 10.1103/PhysRevD.75.076004
DO - 10.1103/PhysRevD.75.076004
M3 - Article
AN - SCOPUS:34247479712
SN - 1550-7998
VL - 75
JO - Physical Review D - Particles, Fields, Gravitation and Cosmology
JF - Physical Review D - Particles, Fields, Gravitation and Cosmology
IS - 7
M1 - 076004
ER -