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Negative parity pentaquarks in large Nc QCD and quark model

Dan Pirjol·Carlos Schat
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Abstract

Recently, the 1/Nc expansion has been applied to the study of exotic baryons containing both quarks and antiquarks. We extend this approach to exotic states with mixed symmetric spin-flavor symmetry, which correspond in the quark model to negative parity pentaquarks, and discuss the large Nc predictions for their mass spectrum. The heavy exotics Qbar q^4 transform as 3, 6bar,15 and 15' under flavor SU(3), while the light states include the exotic multiplets 10bar, 27, 35. We give mass relations among these multiplets following from the 1/Nc expansion. In the quark model, the mass splittings between these states are given by color-spin interactions. Using the observation of an anticharmed exotic by the H1 collaboration, we give predictions for the masses of other expected heavy pentaquarks.

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Dan Pirjol, Carlos Schat. 2005-02-16. Negative parity pentaquarks in large Nc QCD and quark model. https://doi.org/10.1103/physrevd.71.036004

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