2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/184152We present a model for the formation of the charmed pentaquark Theta_c in hard scattering processes such as deep inelastic scattering, e^+e^- annihilation, and high-energy p pbar collisions. The model assumes that the cross section for Theta_c formation is proportional to the rate of production of p D^{*-} (or pbar D^{*+}) pairs in close proximity both in momentum space and in coordinate space. The constant of proportionality is determined from the Theta_c cross section in deep inelastic scattering as reported by the H1 experiment. The HERWIG Monte Carlo is used to generate simulated DIS events and also to model the space-time structure of the final state. Requiring the proton and the D^* be within a 100 MeV mass window and separated by a spacelike distance of no more than 2 fm, we find that a large "coalescence enhancement factor" F_co \sim 10 is required to account for the H1 signal. The same approach is then applied in order to estimate the number and characteristics of Theta_c events produced at LEP and the Tevatron.Expanded general discussion of the coalescence model. Revised sec. 2.4, following correction of an error in HERWIG in the programming of the space-time structure of the underlying event in hadron-hadron collisions. Quantitative changes are smallHigh Energy Physics - PhenomenologyHigh Energy Physics - ExperimentCoalescence model for Theta_c pentaquark formationtext