Study of qqqc(c)over-bar five quark system with three kinds of quark-quark hyperfine interaction

The low-lying energy spectra of five quark systems uudc (c) over bar (I = 1/2, S = 0) and udsc (c) over bar (I = 0, S = -1) are investigated with three kinds of schematic interaction: the chromomagnetic interaction, the flavor-spin-dependent interaction and the instanton-induced interaction. In all the three models, the lowest five-quark state (uudc (c) over bar or udsc (c) over bar) has an orbital angular momentum L = 0 and the spin-parity J(P) = 1/2(-); the mass of the lowest udsc (c) over bar state is heavier than the lowest uudc (c) over bar state.