A Study of the Properties of Muons Produced in the Decays of Charmed Particles
Patricia Louise McBride · 1984
One or the most efficient ways or studying particles with lifetimes OD the order or 5 x $10^{-13}$ seconds is with a high resolution ( <100 $\mu$) visual detector employed ~ a target in a high energy particle beam. The initial particle interactions and subsequent decays can be directly observed and measured. The High Resolution Streamer Chamber. designed and built at Yale, is one such detector. This detector, used in conjunction with a highly selective trigger, produced a data sample or hadronic interactions rich with charm particle production. This dissertation will describe an experiment in which charmed particles produced in collisions of high energy neutrons ($\sim$330 Gev) on Helium-Neon nucleons were observed inside the Streamer Chamber. The primary focus wiU be OD t.he properties or muons generated in the decays of the charmed particles. The average charm branching ratio into electrons has been measured to be 8%. We employed a muon trigger which enhanced the charm content of our data sample by a factor of 40. We measured the momentum and charge of each trigger muon with two steel toroidal magnets. A sample of 23 charm candidates with a background of 5.68 events was observed. From these events we conclude that $D\bar{D}$ production is dominant over associated production of $\Lambda_c ^+\bar{D}$ and that the D's (c$\bar{q}$) are produced centrally in p-N collisions. The measured momentum and transverse momentum spectra are consistent with $D\bar{D}$ production. Furthermore, the results are consistent with the standard model of charm decay which assumes $\mu$-e universality. The average charm lifetime was measured to be (6±1 )x$10^{-13}$sec.