The Proton-Proton Elastic Scattering Processes in the CLAS Detector

The CSUDH Hadronic Structure Laboratory is conducting a program of nuclear physics using short-lived beams using the CLAS Photon Tagger in Hall B at the Thomas Jefferson National Accelerator Facility in Newport News, VA. The beam particle is produced in a photoproduction process on a liquid hydrogen target, and travels only a few cm before decaying; before doing so, it can rescatter on a second proton in the same target. To verify this technique, we are analyzing the process pp→pp with this same approach. A peak at m_X=0.938 GeV/c² in the missing mass plot of the process Xp→pp is evidence for the pp elastic scattering process. In contrast to traditional accelerator-based nuclear physics experiments, both the beam flux and effective target thickness are complicated to determine. The beam flux is determined in a separate analysis of the same dataset, requiring only a single proton. The effective target thickness is determined by a simple geometrical calculation. The acceptance and analysis efficiency are determined using a simulation designed to produce events that are initiated within the target, with beam particles at directions not along the target axis. A successful comparison of the results of this measurement with existing pp→pp data will enable us to extend this technique to short-lived beam particles. This poster will present the motivation behind this research, discuss the current status of our analysis, and future applications of this technique.