Lifetimes of Charmed Particles Produced in a 20 GeV γp Experiment

摘要

The experiment was performed at the SLAC Hybrid Facility with a backward scattered laser beam incident on the 1 m hydrogen bubble chamber operated at 10 Hz. The beam was 3 mm in diameter, peaked at 20 GeV with a FWHM of 2. GeV, and usually contained 25 photons per pulse. Following the bubble chamber were four sets of multiwire proportional chambers (MWPC's), two atmospheric pressure Cerenkov counters, and a lead-glass wall³. All the downstream detectors were deadened in the region containing the e+e- pairs from beam conversions.