Pentaquark Search with Energetic Hadron Beams

Abstract

The strange-anticharmed Pentaquark is a uud(cbar)s or udd(cbar)s five-quark baryon that is expected to be either a narrow resonance, or possibly even stable against strong decay. We describe this hyperon here; its structure, binding energy and lifetime, resonance width, production mechanisms and decay modes. We estimate production cross sections, techniques to reduce backgrounds in search experiments, and how to optimize experiments to observe it. Possibilities for enhancing the signal over background in Pentaquark searches are investigated by examining predictions for detailed momentum and angular distributions in multiparticle final states. General model-independent predictions are presented as well as those from two models: a loosely bound Ds-N "deuteron" and a strongly-bound five-quark model. Fermilab E791 data, currently being analysed, may be marginal for showing definitive signals. Future experiments with more than 10^5 reconstructed charmed baryon events should have sensitivity to determine whether or not the Pentaquark exists.