skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: First year of Mark-J: physics with high energy electron-positron colliding beams. Report No. 107

Technical Report ·
DOI:https://doi.org/10.2172/6949353· OSTI ID:6949353

This report reviews the experimental investigation of high energy e/sup +/e/sup -/ interactions by the MARK J collaboration at PETRA, the electron-positron colliding beam accelerator at DESY in Hamburg, West Germany. The physics objectives include studies of several purely electromagnetic processes and hadronic final states, which further our knowledge of the nature of the fundamental constituents and of their strong, electromagnetic and weak interactions. Before discussing the physics results, the main features and the principal components of the MARK J detector are discussed in terms of design, function, and performance. Several aspects of the online data collection and the offline analysis are also outlined. Results are presented on tests of quantum electrodynamics using e/sup +/e/sup -/ ..-->.. e/sup +/e/sup -/, ..mu../sup +/..mu../sup -/ and tau/sup +/tau/sup -/, on the measurement of R, the ratio of the hadronic to the point-like muon pair cross section, on the search for new quark flavors, on the discovery of three jet events arising from the radiation of hard noncollinear gluons as predicted by quantum chromodynamics, and on the determination of the strong coupling constant ..cap alpha../sub s/.

Research Organization:
Massachusetts Inst. of Tech., Cambridge (USA). Lab. for Nuclear Science
Sponsoring Organization:
USDOE
DOE Contract Number:
AC02-76ER03069
OSTI ID:
6949353
Report Number(s):
DOE/ER/03069-779; TRN: 80-018844
Country of Publication:
United States
Language:
English