We have measured theR value in non-resonante+e− annihilation using the ARGUS detector at the storage ring DORIS II. At a centre-of-mass energy\(\sqrt s= 9.36\) GeV the ratio of the hadronic cross-section to the μ-pair cross section in lowest order QED has been determined to beR=3.46±0.03±0.13. In addition, we have measured the charged-particle multiplicities in non-resonant hadron production at\(\sqrt s= 10.47\) GeV just below theB\(\bar B\) threshold and in ϒ (4S) resonance decays. For the average charged-particle multiplicities in continuum events and ϒ(4S)→B\(\bar B\) decays we obtain <n>cont=8.35±0.02±0.20 and <n>ϒ(4s)=10.81±0.05±0.23.
Using the ARGUS detector at thee+e− storage ring DORIS II, we have investigated inclusive production of π±,K±,Ks0 and\(\bar p\) in multihadron events at 9.98 GeV and in direct decays of the ϒ(1S) meson, i.e. from quark and gluon fragmentation. The most pronounced difference is the rate of baryon production. The Lund Monte Carlo program gives a reasonable qualitative description, although it cannot reproduce our data in detail.
We report on a high statistics study of π0 and η production in continuum events and in direct decays of the Γ(1S) and Γ(2S) resonances. The measured production rates per event are\(\left\langle {n_{\pi ^0 } } \right\rangle\)=3.22 ± 0.07 ± 0.31 (3.97 ± 0.23 ± 0.38) and 〈nη〉=0.19 ± 0.04 ± 0.04 (0.40 ± 0.14 ± 0.09) for continuum events (direct Γ(1S) decays).