Abstract
The ratio of the cross section for annihilation into hadronic final states to the QED cross section for muon-pair production is measured to be 4.34±0.45±0.30 and 4.23±0.20±0.21 at c.m. energies of 50 and 52 GeV, respectively. From these values of and an analysis of the event shapes we deduce a 95%-confidence-level upper limit for the production rate of new heavy charge or quarks to be 0.19 units of .
- Received 25 September 1987
DOI:https://doi.org/10.1103/PhysRevLett.60.93
©1988 American Physical Society