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.
Corrected for radiative effects and acceptance.
Unfolded charged particle multiplicity distribution for continuum events.
Unfolded charged particle multiplicity distribution for UPSILON(4S) events.
We present a study of inclusive π0 and ŋ production ine+e− annihilation at
Particle multiplicities in the continuum.
Particle multiplicities in the UPSILON (1S).
Inclusive pi0 spectra in the continuum.
We report a measurement of the production of antideuterons d in e + e − annihilation at centre-of-mass energies around 10 GeV using the ARGUS detector at the DORIS II storage ring. We observe an enhancement of d production in direct hadronic ϒ (1S) and ϒ (2S) resonance decays. From 21 events width a d candidate the inclusive cross section 1 σ dir had · d σ d p and the production rate of antideuterons are determined. A production rate of (6.0±2.0±0.6) × 10 -5 d per direct hadronic ϒ decay and a 90% CL upper limit of 1.7 × 10 −5 d per e + e − →q q continuum event are obtained. These results are related to antiproton production through a simple model.
Acceptance corrected, background subtracted momentum spectrum observed in UPSI(1S) and UPSI(2S) resonance decays.
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).
First data point in table is from the continuum at sqrt(s)=9.46 GeV.
First data point in table is from the continuum at sqrt(s)=9.46 GeV.
PI0 spectrum in the continuum.
We report on the first observation of Δ(1232) ++ and Δ(1232)++¯ baryons in e + e − annihilation at energies around 10 GeV, using the ARGUS detector at DORIS II. The sum of the rates of Δ ++ and Δ++¯ per hadronic event in the continuum is measured to be 0.040±0.008±0.006, and the rate in direct ϒ(1S) decays is 0.124±0.016±0.015. The momentum spectrum of Δ ++ baryons in direct ϒ(1S) decays has been measured.
Production on the UPSI(1S) resonance.
No description provided.
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.
No description provided.
No description provided.
No description provided.
We report on a high precision measurement of ϕ-meson production in continuum events and in direct decays of the Υ(1S)- and Υ(2S)-mesons. The ratio of the total production rate of ϕ-mesons in direct Υ(1S)- and Υ(2S)-decays over that in continuum events is 1.32±0.08±0.09 and 1.07±0.13±0.11 respectively. This is compatible with the corresponding ratio obtained for lighter mesons, but is appreciably smaller than the relative baryon production rate.
PHI meson cross section on the continuum.
Differential particle density for PHI mesons in decays of upsilon(1S) and upsilon(2S).
No description provided.