308 citations · 2.6k across the 54 of their papers we have counts for
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A Measurement of the tau->electron Branching Ratio
The OPAL Collaboration, G. Abbiendi et al
The branching ratio for the decay tau->e nue nutau has been measured using Z0 decay data collected by the OPAL experiment at LEP. In total 33073 tau->e nue nutau candidates were id…
Bose-Einstein Correlations in e+e- to W+W- at 172 and 183 GeV
The OPAL Collaboration, G. Abbiendi et al
Bose-Einstein correlations between like-charge pions are studied in hadronic final states produced by e+e- annihilations at center-of-mass energies of 172 and 183 GeV. Three event…
Observation of a Coherence Length Effect in Exclusive Rho^0 Electroproduction
K. Ackerstaff
Exclusive incoherent electroproduction of the rho^0(770) meson from 1H, 2H, 3He, and 14N targets has been studied by the HERMES experiment at squared four-momentum transfer Q**2>0.…
Search for Anomalous Photonic Events with Missing Energy in e+e- Collisions at Ecm = 130, 136 and 183 GeV
The OPAL Collaboration, G. Abbiendi et al
Photonic events with large missing energy have been observed in e+e- collisions at centre-of-mass energies of 130, 136 and 183 GeV collected in 1997 using the OPAL detector at LEP.…
A Measurement of Rb using a Double Tagging Method
The OPAL Collaboration, G. Abbiendi et al
The fraction of Z to bbbar events in hadronic Z decays has been measured by the OPAL experiment using the data collected at LEP between 1992 and 1995. The Z to bbbar decays were ta…
Determination of the Deep Inelastic Contribution to the Generalised Gerasimov-Drell-Hearn Integral for the Proton and Neutron
K. Ackerstaff
The virtual photon absorption cross section differences [sigma_1/2-sigma_3/2] for the proton and neutron have been determined from measurements of polarised cross section asymmetri…
Measurement of the Longitudinal Cross-Section using the Direction of the Thrust Axis in Hadronic Events at LEP
The OPAL Collaboration, G. Abbiendi et al
In the process e+e- to hadrons, one of the effects of gluon emission is to modify the 1+cos(theta)**2 form of the angular distribution of the thrust axis, an effect which may be qu…
A Study of Parton Fragmentation in Hadronic Z0 Decays Using Lambda-Lambdabar Correlations
The OPAL Collaboration, G. Abbiendi et al
The correlated production of Lambda and Lambdabar baryons has been studied using 4.3 million multihadronic Zo decays recorded with the OPAL detector at LEP. Di-lambda pairs were in…
First Measurement of Z/gamma* Production in Compton Scattering of Quasi-real Photons
OPAL Collaboration, G. Abbiendi et al
We report the first observation of Z/gamma* production in Compton scattering of quasi-real photons. This is a subprocess of the reaction e+e- to e+e-Z/gamma*, where one of the fina…
Search for Scalar Top and Scalar Bottom Quarks at sqrt(s) = 183 GeV at LEP
The OPAL Collaboration, K. Ackerstaff et al
Searches for a scalar top quark and a scalar bottom quark have been performed using a total data sample of 56.8 pb-1 at a centre-of-mass energy of 183 GeV collected with the OPAL d…
Measurement of the Strong Coupling Constant and the Vector and Axial-Vector Spectral Functions in Hadronic Tau Decays
The OPAL Collaboration, K. Ackerstaff et al
The spectral functions of the vector current and the axial-vector current have been measured in hadronic tau decays using the OPAL detector at LEP. Within the framework of the Oper…
Measurement of the Michel Parameters in Leptonic Tau Decays
The OPAL Collaboration, K. Ackerstaff et al
The Michel parameters of the leptonic tau decays are measured using the OPAL detector at LEP. The Michel parameters are extracted from the energy spectra of the charged decay lepto…
Search for Higgs Bosons and New Particles Decaying into Two Photons at sqrt(s) = 183 GeV
The OPAL Collaboration, K. Ackerstaff et al
A search for the resonant production of high mass photon pairs associated with a leptonic or hadronic system has been performed using a data sample of 57.7 pb-1 collected at an ave…
Measurement of Tau Branching Ratios to Five Charged Hadrons
The OPAL Collaboration, K. Ackerstaff et al
The branching ratios of the decay of the tau lepton to five charged hadrons have been measured with the OPAL detector at LEP using data collected between 1991 and 1995 at e+e- cent…
Inclusive Production of Charged Hadrons and K_s Mesons in Photon-Photon Collisions
The OPAL Collaboration, K. Ackerstaff et al
The production of charged hadrons and K_s mesons in the collisions of quasi-real photons has been measured using the OPAL detector at LEP. The data were taken at e+e- centre-of-mas…
Measurement of the Average Polarization of b Baryons in Hadronic Z^0 Decays
The OPAL Collaboration, G. Abbiendi et al
In the Standard Model, b quarks produced in e^+e^- annihilation at the Z^0 peak have a large average longitudinal polarization of -0.94. Some fraction of this polarization is expec…
Measurements of Flavour Dependent Fragmentation Functions in Z^0 -> qq(bar) Events
The OPAL Collaboration, K. Ackerstaff et al
Fragmentation functions for charged particles in Z -> qq(bar) events have been measured for bottom (b), charm (c) and light (uds) quarks as well as for all flavours together. The r…
The Flavor Asymmetry of the Light Quark Sea from Semi-inclusive Deep-inelastic Scattering
K. Ackerstaff
The flavor asymmetry of the light quark sea of the nucleon is determined in the kinematic range 0.02<x<0.3 and 1 GeV^2<Q^2<10 GeV^2, for the first time from semi-inclusive deep-ine…
The HERMES Spectrometer
K. Ackerstaff
The HERMES experiment is collecting data on inclusive and semi-inclusive deep inelastic scattering of polarised positrons from polarised targets of H, D, and He. These data give in…
Beam-Induced Nuclear Depolarisation in a Gaseous Polarised Hydrogen Target
K. Ackerstaff
Spin-polarised atomic hydrogen is used as a gaseous polarised proton target in high energy and nuclear physics experiments operating with internal beams in storage rings. When such…
Photon and Light Meson Production in Hadronic Z^0 Decays
The OPAL Collaboration, K. Ackerstaff et al
The inclusive production rates and differential cross-sections of photons and mesons with a final state containing photons have been measured with the OPAL detector at LEP. The lig…
Search for Stable and Long-Lived Massive Charged Particles with the OPAL Detector at LEP in e+e- Collisions at \sqrt{s}=130-183 GeV
The OPAL Collaboration, K. Ackerstaff et al
A search for stable and long-lived massive particles of electric charge |Q/e| = 1 or 2/3, pair-produced in e+e- collisions at centre-of-mass energies from 130 to 183 GeV, is report…
An upper limit on the anomalous magnetic moment of the τlepton
The OPAL Collaboration, K. Ackerstaff et al
Using radiative Z^0 -> τ^+ τ^- γevents collected with the OPAL detector at LEP at \sqrt{s}= M_Z during 1990-95, a direct study of the electromagnetic current at the τγvertex has be…
A Search for Neutral Higgs Bosons in the MSSM and Models with Two Scalar Field Doublets
The OPAL Collaboration, K. Ackerstaff et al
A search is described for the neutral Higgs bosons h^0 and A^0 predicted by models with two scalar field doublets and, in particular, the Minimal Supersymmetric Standard Model (MSS…