Search for a “top” threshold in hadronic e+e− annihilation at energies between 22 and 31.6 GeV

Abstract Results on e + e − annihilation into hadrons at c.m. energies between 22 and 31.6 GeV are presented. The data were accumulated with the PLUTO detector at PETRA. The events are dominantly of the two-jet type. The value of the relative hadronic cross section R =3.88 ± 0.22 along with the details of the sphericity and thrust distribution rule out an open (tt) channel (Q t = 2 3 ) below 30 GeV. The inclusive muon results support the above conclusion.