Stable heavy pentaquark states

If the Theta(+) (1540) is interpreted as a bound state of a (s) over bar quark and two (ud) diquarks in a relative P-wave, then it is very likely that there exist pentaquark states with a heavy antiquark, (b) over bar or (c) over bar, and two light diquarks in a relative S-wave which are stable against strong decays. We make a mass estimate for exotic states of this type and discuss their weak decays. Isospin relations are constructed which test their flavor quantum numbers. (C) 2004 Published by Elsevier B.V.