e+e- annihilation into hadrons was studied at CM energies between 39.8 and 45.2 GeV and a search was made for new heavy quarks. No evidence was found for the existence of a narrow state excluding the possible existence of the lowest vector toponium state in this mass range. A search for continuum production of heavy quarks led to lower mass limits for new quarks of 22.0 GeV (eQ = 2 3) and 21.0 GeV (eQ = 1 3). Quarks are found to be pointlike, the corresponding mass parameter being larger than 288 GeV. A fit of the QCD and the electroweak contributions to R=σtot/σμμ yielded sin2θW = 0.30-0.07 +0.23.
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics