Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Measurement of the charged particle multiplicity distribution in hadronic Z decays
AU - Decamp, D.
AU - Finch, Alexander
AU - ALEPH Collaboration
PY - 1991
Y1 - 1991
N2 - The charged particle multiplicity distribution of hadronic Z decays was measured on the peak of the Z resonance using the ALEPH detector at LEP. Using a model independent unfolding procedure the distribution was found to have a mean 〈n〉=20.85±0.24 and a dispersion D=6.34±0.12. Comparison with lower energy data supports the KNO scaling hypothesis in the energy range GeV. At GeV the shape of the multiplicity distribution is well described by a log-normal distribution, as predicted from a cascading model for multi-particle production. The same model also successfully describes the energy dependence of the mean and width of the multiplicity distribution. A next-to-leading order QCD prediction in the framework of the modified leading-log approximation and local parton-hadron duality is found to fit the energy dependence of the mean but not the width of the charged multiplicity distribution, indicating that the width of the multiplicity distribution is a sensitive probe for higher order QCD or non-perturbative effects.
AB - The charged particle multiplicity distribution of hadronic Z decays was measured on the peak of the Z resonance using the ALEPH detector at LEP. Using a model independent unfolding procedure the distribution was found to have a mean 〈n〉=20.85±0.24 and a dispersion D=6.34±0.12. Comparison with lower energy data supports the KNO scaling hypothesis in the energy range GeV. At GeV the shape of the multiplicity distribution is well described by a log-normal distribution, as predicted from a cascading model for multi-particle production. The same model also successfully describes the energy dependence of the mean and width of the multiplicity distribution. A next-to-leading order QCD prediction in the framework of the modified leading-log approximation and local parton-hadron duality is found to fit the energy dependence of the mean but not the width of the charged multiplicity distribution, indicating that the width of the multiplicity distribution is a sensitive probe for higher order QCD or non-perturbative effects.
U2 - 10.1016/0370-2693(91)90575-B
DO - 10.1016/0370-2693(91)90575-B
M3 - Journal article
VL - 273
SP - 181
EP - 192
JO - Physics Letters B
JF - Physics Letters B
SN - 0370-2693
IS - 1-2
ER -