Radiative events e+e-->Z0->qbar(q)gamma were selected from the samples of hadronic Z0 decays collected by the ALEPH, DELPHI, L3 and OPAL detectors at LEP. Exploiting the difference between the flavour composition of multihadronic events with final state isolated photons and that of all multihadrons, te weak couplings of up and down type quarks were measured to be (DELPHI, L3 and OPAL): cu=0.93±0.14; cd=1.64±0.09. The Quark to Photon Fragmentation Function Dq->gamma was determined both from the yield of non isolated photons (ALEPH) and from the inclusive gamma energy spectrum inside hadronic jets (OPAL). The String Effect was investigated from the comparison of the charged particles flow in the region between the quark and the anti-quark in qbar(q)g and qbar(q)gamma events (L3, OPAL). The study of the charged particle multiplicity scale dependence in gluon and quark jets allowed the determination of the colour factors ratio (DELPHI): CA/CF=2.34±0.04±0.11.
Prompt photons at LEP 1
MARGONI, MARTINO
1998
Abstract
Radiative events e+e-->Z0->qbar(q)gamma were selected from the samples of hadronic Z0 decays collected by the ALEPH, DELPHI, L3 and OPAL detectors at LEP. Exploiting the difference between the flavour composition of multihadronic events with final state isolated photons and that of all multihadrons, te weak couplings of up and down type quarks were measured to be (DELPHI, L3 and OPAL): cu=0.93±0.14; cd=1.64±0.09. The Quark to Photon Fragmentation Function Dq->gamma was determined both from the yield of non isolated photons (ALEPH) and from the inclusive gamma energy spectrum inside hadronic jets (OPAL). The String Effect was investigated from the comparison of the charged particles flow in the region between the quark and the anti-quark in qbar(q)g and qbar(q)gamma events (L3, OPAL). The study of the charged particle multiplicity scale dependence in gluon and quark jets allowed the determination of the colour factors ratio (DELPHI): CA/CF=2.34±0.04±0.11.Pubblicazioni consigliate
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