Pentaquark Update After Ten Years

Studying scattering of heavy flavor hadrons and looking for bound states is shown to give experimental information otherwise unobtainable about effective two-body interactions between constituent (qq)6 and (q̄q)8 pairs respectively in color sextet and color octet states. All the successes of the constituent quark model in (uds) hadron spectroscopy are shown to depend only on effective two-body interactions in color 3 and singlet states. New directions for bound pentaquark searches are discussed following the availability of vertex detectors which can pinpoint events where a proton is emitted from a secondary vertex. Any such event indicates a particle decaying weakly by proton emission and the discovery of a new particle if its mass is higher than that of known charmed baryons. There is no combinatorial background and striking decay signatures like pφπ are no longer needed. The beauty pentaquark (b̄suud) and the doubly-strange pentaquark (c̄ssud) may be relevant to future searches. A simple calculation shows that the effects of flavor-SU(3) breaking on their binding relative to the relevant thresholds are similar to that for the singly-strange pentaquark (c̄suud) relative to the Dsp threshold.