Measurement of event shape and inclusive distributions at $\sqrt{s} =$ 130 and 136 GeV

Abstract

Inclusive charged particle and event shape distributions are measured using 321 hadronic events collected with the DELPHI experiment at LEP at effective centre of mass energies of 130 to 136 GeV. These distributions are presented and compared to data at lower energies, in particular to the precise Z data. Fragmentation models describe the observed changes of the distributions well. The energy dependence of the means of the event shape variables can also be described using second order QCD plus power terms. A method independent of fragmentation model corrections is used to determine s from the energy dependence of the mean thrust and heavy jet mass. It is measured to be: s(133 GeV) = 0:116 0:007exp +0:005 􀀀0:004theo from the high energy data.