Pentaquark baryon production in nuclear reactions
Using a hadronic model with empirical coupling constants and form factors, we have evaluated the cross sections for the production of exotic pentaquark $\Theta^+$ and/or $\Xi_5^+$ and $\Xi_5^{--}$ in reactions induced by photons, nucleons, pions, and kaons on nucleon targets. We have also predicted the $\Theta^+$ yield in relativistic heavy ion collisions using a kinetic model that takes into account both $\Theta^+$ production from the coalescence of quarks and antiquarks in the quark-gluon plasma and the effects due to subsequent hadronic absorption and regeneration.