A Search For Single Electron Production In Electron Positron Annihilation At E PDF Download

This thesis presents experimental results from the ASP detector which took data on ee− interactions in the PEP storage ring at SLAC. Its design was particularly suitable for searching for production of supersymmetric particles. The motivations for and phenomenology of Supersymmetry are discussed. In particular, the production of a single supersymmetric electron (selectron'', {tilde e}) in combination with a supersymmetric photon (photino'', {tilde {gamma}}) would result in events in which a single electron and no other particles are observed in the detector at an ee− collider such as PEP, provided the masses of these particles are not too large. Such events would also result from the production of a single supersymmetric W-boson (wino'', {tilde W}) in combination with a supersymmetric neutrino (sneutrino'', {tilde {nu}}). These processes make it possible to search for electrons and winos with masses greater than the beam energy. Observation of these unusual events would distinctly indicate the production of new particles. The ASP detector was designed to be hermetic and to provide efficient event reconstruction for low multiplicity events. The detector is described and its performance is evaluated; it is found to be well-suited to this study. The data sample collected with the detector was thoroughly analyzed for evidence of single-electron events. The various possible background processes are considered and Monte Carlo calculations of the distributions from single selectron and single wino production are presented. Using this information an efficient off-line event selection process was developed, and it is described in detail. 82 refs., 41 figs., 4 tabs.