Quartic Gauge Couplings and the Radiation Zero in pp to l nu gamma gamma events at the LHC (2009)
We report a study of the process pp to l nu gamma gamma at CERN's Large Hadron Collider, using a leading order partonic-level event generator interfaced to the Pythia program for showering and...
Measurement of $\alpha_{s}$ with Radiative Hadronic Events (2009)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Anagnostou, G, Anderson, K J, ...
Hadronic final states with a hard isolated photon are studied using data taken at centre-of-mass energies around the mass of the Z0 boson with the OPAL detector at LEP. The strong coupling alpha S is...
Expected Performance of the ATLAS Experiment - Detector, Trigger and Physics (2008)
Abat, E., Abbott, B., Abdallah, J., Abdelalim, A. A., Abdesselam, A., ...
A detailed study is presented of the expected performance of the ATLAS detector. The reconstruction of tracks, leptons, photons, missing energy and jets is investigated, together with the performance...
Search for Charged Higgs Bosos in $e^{+}e^{-}$ Collisions at $\sqrt{s}$ = 189-209 GeV (2008)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Anagnostou, G, Anderson, K J, ...
A search is made for charged Higgs bosons predicted by Two-Higgs-Doublet extensions of the Standard Model (2HDM) using electron-positron collision data collected by the OPAL experiment at...
Search for Charged Higgs Bosos in e+e- Collisions at sqrts(s) = 189-209 GeV (2008)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Anagnostou, G, Anderson, K J, ...
A search is made for charged Higgs bosons predicted by Two-Higgs-Doublet extensions of the Standard Model (2HDM) using electron-positron collision data collected by the OPAL experiment at...
Alignment of the Pixel and SCT Modules for the 2004 ATLAS Combined Test Beam (2008)
Ahmad, A., Andreazza, A., Atkinson, T., Baines, J., Barr, A. J., Beccherle, R., ...
A small set of final prototypes of the ATLAS Inner Detector silicon tracker (Pixel and SCT) were used to take data during the 2004 Combined Test Beam. Data were collected from runs with beams of...
Glutamate dehydrogenase as putative target for antimalarial drug design (2008)
I. M. Mcmillan, P. J. Bell, A. Müller
Every year 300-500 million cases of malaria occur worldwide, resulting in over one million deaths, most of which are among children under 5 years of age. In humans the disease is caused by one or...
Measurement of the $e^+ e^- \to W^+ W^-$ cross section and W decay branching fractions at LEP (2007)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Anagnostou, G, Anderson, K J, ...
From a total data sample of 701.1 pb^-1 recorded with e+e- centre-of-mass energies of sqrt = 161-209 GeV with the OPAL detector at LEP, 11693 W-pair candidate events are selected. These data are used...
Bose-Einstein study of position-momentum correlations of charged pions in hadronic Z0 decays (2007)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Anagnostou, G, Anderson, K J, ...
A study of Bose-Einstein correlations in pairs of identically charged pions produced in e+e- annihilations at the Z0 peak has been performed for the first time assuming a non-static emitting source....
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Anagnostou, G, Anderson, K J, ...
A search is performed for Higgs bosons decaying into invisible final states, produced in association with a Zo boson in e+e- collisions at energies between 183 and 209 GeV. The search is based on...
Search for Dirac Magnetic Monopoles in $e^{+}e^{-}$ Collisions with the OPAL Detector at LEP2 (2007)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Anagnostou, G, Anderson, K J, ...
This letter describes a direct search for pair produced magnetic monopoles in e+e- collisions. The analysis is based on 62.7 pb^-1 of data collected with the OPAL detector at an average...
Inclusive Jet Production in Photon-Photon Collisions at $\sqrt{^{s}ee}$ from 189 to 209 GeV (2007)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Anagnostou, G, Anderson, K J, ...
Inclusive jet production (e+e- -> e+e- +jet+X) is studied in collisions of quasi-real photons radiated by the LEP beams at e+e- centre-of-mass energies sqrt see from 189 to 209 GeV. Jets are...
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Anagnostou, G, Anderson, K J, ...
This paper describes a topological search for an invisibly decaying Higgs boson,H, produced via the Bjorken process (e+e- -> HZ). The analysis is based on data recorded using the OPAL detector at LEP...
QCD coherence and correlations of particles with restricted momenta in hadronic Z decays (2006)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Anagnostou, G, Anderson, K J, ...
QCD coherence effects are studied based on measurements of correlations of particles with either restricted transverse momenta, pT
Precision Electroweak Measurements on the Z Resonance (2006)
Schael, S, Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Allison, J, ...
We report on the final electroweak measurements performed with data taken at the Z resonance by the experiments operating at the electron-positron colliders SLC and LEP. The data consist of 17...
Search for Neutral MSSM Higgs Bosons at LEP (2006)
Schael, S, Zivkovic, L, Achard, P, Adriani, O, Aguilar-Benítez, M, Alcaraz, J, ...
The four LEP collaborations, ALEPH, DELPHI, L3 and OPAL, have searched for the neutral Higgs bosons which are predicted by the Minimal Supersymmetric Standard Model (MSSM). The data of the four...
Search for Neutral MSSM Higgs Bosons at LEP (2006)
Schael, S, Achard, P, Adriani, O, Aguilar-Benítez, M, Alcaraz, J, Alemanni, G, ...
The four LEP collaborations, ALEPH, DELPHI, L3 and OPAL, have searched for the neutral Higgs bosons which are predicted by the Minimal Supersymmetric Standard Model (MSSM). The data of the four...
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Anagnostou, G, Anderson, K J, ...
Data from e+e- annihilation into hadrons at centre-of-mass energies between 91 GeV and 209 GeV collected with the OPAL detector at LEP, are used to study the four-jet rate as a function of the Durham...
Search for neutral MSSM Higgs bosons at LEP (2006)
Schael, S., Barate, R., Bruneliere, R., De Bonis, I., Decamp, D., Goy, C., ...
The four LEP collaborations, ALEPH, DELPHI, L3 and OPAL, have searched for the neutral Higgs bosons which are predicted by the Minimal Supersymmetric standard model (MSSM). The data of the four...
Colour reconnection in $e^{+}e^{-}\to W^{+}W^{-}$ at $\sqrt{s}$ = 189 - 209 GeV$ (2005)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Allison, J, Amaral, P, ...
The effects of the final state interaction phenomenon known as colour reconnection are investigated at centre-of-mass energies in the range $\sqrt{s}~ 189-209 GeV using the OPAL detector at LEP....
Measurement of the mass and width of the W boson (2005)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Allison, J, Amaral, P, ...
The mass and width of the W boson are measured using e+e- -> W+W- events from the data sample collected by the OPAL experiment at LEP at centre-of-mass energies between 170 GeV and 209 GeV. The mass...
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Allison, J, Amaral, P, ...
Searches were performed for topologies predicted by gauge-mediated Supersymmetry breaking models (GMSB). All possible lifetimes of the next-to-lightest SUSY particle (NLSP), either the lightest...
Determination of $\alpha_{s}$ using Jet Rates at LEP with the OPAL detector (2005)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Anagnostou, G, Anderson, K J, ...
Hadronic events produced in e+e- collisions by the LEP collider and recorded by the OPAL detector were used to form distributions based on the number of reconstructed jets. The data were collected...
Campabadal, F, Fleta, C, Key, M, Lozano, M, Martinez, C, Pellegrini, G, ...
The ABCD3TA is a 128-channel ASIC with binary architecture for the readout of silicon strip particle detectors in the Semiconductor Tracker of the ATLAS experiment at the Large Hadron Collider (LHC)....
Measurement of the running of the QED coupling in small-angle Bhabha scattering at LEP (2005)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Anagnostou, G, Anderson, K J, ...
Using the OPAL detector at LEP, the running of the effective QED coupling alpha(t) is measured for space-like momentum transfer through its effect on the angular spectrum of small-angle Bhabha...
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Allison, J, Amaral, P, ...
A study of Z-boson pair production in e+e- annihilation at center-of-mass energies between 190 GeV and 209 GeV is reported. Final states containing only leptons, (l+l-l+l- and l+l-nn), quark and...
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Allison, J, Amaral, P, ...
We have studied hadronic events from e+e- annihilation data at centre-of-mass energies from 91 to 209 GeV. We present distributions of event shape observables and their moments at each energy and...
Measurement of $R_b$ in $e^+ e^-$ Collisions at 182 - 209 GeV (2004)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Allison, J, Amaral, P, ...
Measurements of Rb, the ratio of the bbbar cross-section to the qqbar cross- section in e+e- collisions, are presented. The data were collected by the OPAL experiment at LEP at centre-of-mass...
Search for Radions at LEP2 (2004)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Allison, J, Amaral, P, ...
A new scalar resonance, called the radion, with couplings to fermions and bosons similar to those of the Higgs boson, is predicted in the framework of Randall-Sundrum models, proposed solutions to...
Determination of the LEP Beam Energy using Radiative Fermion-pair Events, 2004 (2004)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Allison, J, Amaral, P, ...
We present a determination of the LEP beam energy using "radiative return" fermion-pair events recorded at centre-of-mass energies from 183 GeV to 209 GeV. We find no evidence of a disagreement...
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Allison, J, Amaral, P, ...
Upper limits on the cross-section of the pair-production process e+e- -> h0A0 assuming 100% decays into hadrons, are derived from a new search for the h0A0 -> hadrons topology, independent of the...
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Allison, J, Amaral, P, ...
Events with a final state consisting of two or more photons and large missing transverse energy have been observed in e+e- collisions at centre-of-mass energies in the range 192 - 209 GeV using the...
Search for neutral Higgs bosons in CP-conserving and CP-violating MSSM scenarios (2004)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Allison, J, Amaral, P, ...
This report summarizes the final results from the OPAL collaboration on searches for neutral Higgs bosons predicted by the Minimal Supersymmetric Standard Model (MSSM). CP-conserving and for the...
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Allison, J, Amaral, P, ...
Flavour inclusive, udsc and b fragmentation functions in unbiased jets, and flavour inclusive, udsc, b and gluon fragmentation functions in biased jets are measured in e+e- annihilations from data...
Measurement of the Strange Spectral Function in Hadronic $\tau$ Decays (2004)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Allison, J, Amaral, P, ...
Tau Lepton decays with open strangeness in the final state are measured with the OPAL detector at LEP to determine the strange hadronic spectral function of the tau lepton. The decays tau- ->...
Study of Bose-Einstein Correlations in $e^{+}e^{-}\to W^{+}W^{-}$ events at LEP (2004)
Abbiendi, G, Ainsley, C, Åkesson, T, Alexander, G, Allison, J, Amaral, P, ...
Bose-Einstein correlation between like-sign charged-particle pairs in e+e- -> W+W- events recorded with the OPAL detector at LEP at centre-of-mass energies between 183 GeV and 209 GeV are studied....
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Allison, J, Amaral, P, ...
Anomalous quartic couplings between the electroweak gauge bosons may contribute to the vv gamma gamma and qq gamma gamma final states produced in e+e- collisions. This analysis uses the LEP2 OPAL...
Search for Chargino and Neutralino Production at $\sqrt{s}$ = 192-209 GeV at LEP (2004)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Allison, J, Amaral, P, ...
Approximately 438 pb-1 of e+e- data from the OPAL detector, taken with the LEP collider running at centre-of-mass energies of 192-209 Gev, are analyzed to search for evidence of chargino pair...
W Boson Polarisation at LEP2 (2003)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Allison, J, Amaral, P, ...
Elements of the spin density matrix for W bosons in e+e- -> W+W- -> qqln events are measured from data recorded by the OPAL detector at LEP. This information is used calculate polarised differential...
Measurement of the partial widths of the Z into up- and down-type quarks (2003)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Allison, J, Amaral, P, ...
Using the entire OPAL LEP1 on-peak Z hadronic decay sample, Z -> qbarq gamma decays were selected by tagging hadronic final states with isolated photon candidates in the electromagnetic calorimeter....
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Allison, J, Amaral, P, ...
A search for the Higgsstrahlung process e+e- -> hZ is described, where the neutral Higgs boson h is assumed to decay into hadronic final states. In order to be sensitive to a broad range of models,...
Search for R-parity violating decays of sfermions at LEP (2003)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Allison, J, Amaral, P, ...
A search for pair-produced scalar fermions under the assumption that R-parity is not conserved has been performed using data collected with the OPAL detector at LEP. The data samples analysed...
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Allison, J, Amaral, P, ...
We present the first experimental results based on the jet boost algorithm, a technique to select unbiased samples of gluon jets in e+e- annihilations, i.e. gluon jets free of biases introduced by...
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Allison, J, Amaral, P, ...
Cross-section and angular distributions for hadronic and lepton-pair final states in e+e- collisions at centre-of-mass energies between 189 GeV and 209 GeV, measured with the OPAL detector at LEP,...
A Study of $W^{+}W^{-}\gamma$ Events at LEP (2003)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Allison, J, Amaral, P, ...
A study of W+W- events accomanied by hard photon radiation produced in e+e- collisions at LEP is presented. Events consistent with being two on-shell W bosons and an isolated photon are selected from...
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Allison, J, Amaral, P, ...
In total 1317 di-lepton events with significant missing transverse momentum were identified in a total data sample of 680 pb-1 collected at e+e- centre-of-mass energies ranging from 183 GeV to 209...
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Allison, J, Amaral, P, ...
A search for single production of doubly-charged Higgs bosons has been performed using 600.7 pb^-1 of e+e- collision data with sqrt(s)=189--209GeV collected by the OPAL detector at LEP. No evidence...
A study of charm production in beauty decays with the OPAL detector at LEP (2003)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Allison, J, Amaral, P, ...
Using an inclusive method, BR(b -> D\bar{D}X) has been measured in hadronic Z^0 decays with the OPAL detector at LEP. The impact parameter significance of tracks opposite tagged b-jets is used to...
Measurement of charged current triple gauge boson couplings using W pairs at LEP (2003)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Allison, J, Amaral, P, ...
Triple gauge boson couplings are measured from W-pair and single photon events recorded by the OPAL detector at LEP at center-of-mass energies between 183 - 209 GeV with a total integrated luminosity...
Abbiendi, G, Carter, A, De Wolf, E, McPherson, R A, Neal, H, Thomson, M, ...
Hadronic Z0 decays with identified electrons or muons have been used to measure the forward-backward asymmetries of e^+e^- --> Z0 --> bbbar and e^+e^- --> Z0 --> ccbar events. The asymmetries at...
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Allison, J, Amaral, P, ...
Gluon jets with a mean energy of 22 GeV and purity of 95% are selected from hadronic Z0 decay events produced in e+e- annihilations. A subsample of these jets is identified which exhibits a large gap...
Abbiendi, G, Ainsley, C, Alexander, G, Åkesson, P F, Allison, J, Amaral, P, ...
For the first time at LEP the production of prompt photons is studied in the collisions of quasi-real photons using the OPAL data taken at e+e- centre-of-mass energies between 183 GeV and 209 GeV....
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Allison, J, Amaral, P, ...
A search for pair-produced leptoquarks is performed using e+e- collision events collected by the OPAL detector at LEP at centre-of-mass energies between 189 and 209 GeV. The data sample corresponds...
Abbiendi, G, Ainsley, C, Alexander, G, Allison, J, Amaral, P, Anagnostou, G, ...
A search for stable and long-lived massive particles of electric charge |Q/e|=1 or fractional charges of 2/3, 4/3, and 5/3 is reported using data collected by the OPAL detector at LEP, at...
Test of non-commutative QED in the process $e^{+}e^{-} \to \gamma \gamma$ at LEP (2003)
Abbiendi, G, Ainsley, C, Alexander, G, Allison, J, Amaral, P, Anagnostou, G, ...
Non-communicative QED would lead to deviations from the Standard Model depending on a new energy scale $\Delta_{NC}$ and a unique direction in space defined by two angles $\eta$ and $\xi$. Here in...
Bose-Einstein Correlations of $\pi^{0}$ Pairs from Hadronic $Z^{0}$ Decays (2003)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, Amaral, P, ...
We observed Bose-Einstein correlation in pi0 pairs produced in Z0 decays using the data sample collected by the OPAL detector at LEP 1 from 1991 to 1995. Using a static Gaussian picture for the pion...
A Measurement of Semileptonic B Decays to Narrow Orbitally-Excited Charm Mesons (2003)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, Amaral, P, ...
The decay chain b -> Bbar -> D^{**0} l nu X, D^{**0} -> D^{*+} pi^-, D^{*+} -> D^0 pi^+, D^0 ->(Kpi or K3pi) is identified in a sample of 3.9 million hadronic Z decays collected with the OPAL...
Di-Jet Production in Photon-Photon colisions at $\sqrt{s_{ee}}$ from 189 to 209 GeV (2003)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, Amaral, P, ...
Di-jet producion is studied in collisions of quasi-real photons at e+e- centre- of-mass energies sqrt(s)ee from 189 to 209 GeV at LEP. The data were collected with the OPAL detector. Jets are...
A Study of W+ W- gamma events at LEP (2003)
OPAL Collaboration, Abbiendi, G, Ainsley, C, Akesson, P F, Alexander, G, Allison, J, ...
Search for chargino and neutralino production at s**(1/2) = 192-GeV to 209 GeV at LEP (2003)
OPAL Collaboration, Abbiendi, G, Ainsley, C, Akesson, P F, Alexander, G, Allison, J, ...
A Measurement of the $\tau^{-}\to \mu^{-}\overline{\nu}_{\mu}\nu_{\tau}$ Branching Ratio (2002)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, Amaral, P, ...
The tau -> mu nu nu branching ratio has been measured using data collected from 1990 to 1995 by the OPAL detector at the LEP collider. The resulting value of B(tau -> mu nu nu) = 0.1734 +-...
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, Amaral, P, ...
We have measured the mean charged particle multiplicities separately for bbbar, ccbar and light quark (uubar, ddbar, ssbar) initiated events produced in e+e- annihilations at LEP. The data were...
Multi-Photon Production in $e^{+}e^{-}$ collisions at $\sqrt{s}$ = 181 - 209 GeV (2002)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, Amaral, P, ...
The process e+e- -> gamma gamma (gamma) is studied using data collected by the OPAL detector at LEP between the years 1997 and 2000. The data set corresponds to an integrated luminosity of 672.3pb-1...
Search for Nearly Mass-Degenerate Charginos and Neutralinos at LEP (2002)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, Amaral, P, ...
A search was performed for charginos with masses close to the mass of the lightest neutralino in e+e- collisions at centre-of-mass energies of 189-209 GeV recorded by the OPAL detector at LEP. Events...
Search for the Standard Model Higgs Boson with the OPAL Detector at LEP (2002)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, Amaral, P, ...
This paper summarises the search for the Standard Model Higgs boson in e+e- collisions at centre-of-mass energies up to 209 GeV performed by the OPAL Collaboration at LEP. The consistency of the data...
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, Amaral, P, ...
The b quark forward-backward asymmetry has been measured using hadronic Z0 decays collected by the OPAL experiment at LEP. Z0 -> bbbar decays were selected using a combination of secondary vertex and...
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, G, Allison, J, Amaral, P, ...
We have analysed the data collected by OPAL at centre-of-mass energies between 189 and 209 GeV searching for Higgs boson candidates from the process e/sup +/e/sup -/ to h/sup 0/Z/sup 0/ followed by...
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, Amaral, P, ...
The exclusive production of proton-antiproton pairs in the collisions of two quasi-real photons had been studied using data taken at sqrt(s)_ee=183 GeV and 189 GeV with the OPAL detector at LEP....
Charged Particle Momentum Spectra in $e^+ e^-$ annihilation at $\sqrt{s}$ = 192-209 GeV (2002)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, Amaral, P, ...
Charged particle momentum distributions are studied in the reaction e+e- -> hadrons, using data collected with the OPAL detector at centre-of-mass energies from 192 GeV to 209 GeV. The data...
Search for scalar top and scalar bottom quarks at LEP (2002)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, Amaral, P, ...
Searches for a scalar top quark and a scalar bottom quark have been performed using a data sample of 438 pb-1 at centre-of-mass energies of sqrt(s) = 192 - 209 GeV collected with the OPAL detector at...
Measurement of Neutral-Current Four-Fermion Production at LEP2 (2002)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, Amaral, P, ...
Four-fermion final states qqbar e+e- and qqbar mu+mu- from neutral-current interactions in e+e- collisions are studied in the OPAL detector at LEP at centre-of-mass energies from 183 GeV to 209 GeV....
Inclusive Analysis of the b Quark Fragmentation Function in Z Decays at LEP (2002)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, Amaral, P, ...
A study of b quark hadronisation is presented using inclusively reconstructed B hadrons in about four million hadronic Z decays recorded in 1992-2000 with the OPAL detector at LEP. The data are...
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, Amaral, P, ...
A search is performed for production of short-lived particles in e+e- -> XY, with X -> gamma gamma and Y -> ffbar, for scalar X and scalar or vector Y. Model-independent limits in the range of 25-60...
Search for Charged Excited Leptons in $e^+ e^-$ Collisions at $\sqrt{s}$ = 183-209 GeV (2002)
Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, Amaral, P, Anagnostou, G, ...
A search for charged excited leptons decaying into a lepton and photon has been performed using approximately 680 pb-1 of e+e- collision data collected by the OPAL detector at LEP at centre-of-mass...
Decay-mode independent searches for new scalar bosons with the OPAL detector at LEP (2002)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, Amaral, P, ...
This paper describes topological searches for neutral scalar bosons S0 produced in association with a Z0 boson via the Bjorken process e+e- -> S0Z0 at centre-of-mass energies of 91 GeV and 183-209...
Measurement of the Charm structure Function $F_{2}^{\gamma},c$ of the Photon at LEP (2002)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, Amaral, P, ...
The production of charm quarks is studied in deep-inelastic electron-photon scattering using data recorded by the OPAL detector at LEP at normal e+e- centre-of-mass energies from 183 to 209 GeV. The...
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, Anagnostou, G, ...
A novel method of determining the mass of the W boson in the W+W- -> lnu lnu channel is presented and applied to 667pb^-1 of data recorded at the center-of- mass energies in the range 183-207 GeV...
Measurement of the Hadronic Photon Structure Function $F_{2}^{\gamma}$ at LEP2 (2002)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, Anagnostou, G, ...
The hadronic structure of the photon F2gamma is measured as a function of Bjorken x and of the photon virtuality Q2 using deep-inelastic scattering data taken by the OPAL detector at LEP at e+e-...
Thesis (M. Soc. Sc.) -- Lincoln University, 2002.
Search for Leptoquarks in Electron-Photon Scattering at $\sqrt{s_{ee}}$ up to 209 GeV at LEP (2001)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, Anagnostou, G, ...
Searches for first generation scalar and vector leptoquarks, and for squarks in R-parity violating SUSY models with the direct decay of the squark into Standard Model particles, have been performed...
Search for Doubly Charged Higgs Bosons with the OPAL detector at LEP (2001)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, Anagnostou, G, ...
A search for pair-produced doubly charged Higgs bosons has been performed using data samples corresponding to an integrated luminosity of about 614 pb-1 collected with the OPAL detector at LEP at...
Particle multiplicity of unbiased gluon jets from $e^+ e^-$ three-jet events (2001)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, Anagnostou, G, ...
The charged particle multiplicities of two- and three-jet events from the reaction e+e- -> Z0 -> hadrons are measured for Z0 decays to light quark (uds) flavors. Using recent theoretical expressions...
Search for Yukawa Production of a Light Neutral Higgs Boson at LEP (2001)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, Anagnostou, G, ...
Within a Two-Higgs-Doublet Model (2HDM) a search for a light Higgs boson in the mass range of 4-12 GeV has been performed in the Yukawa process e+e- -> b bbar A/h -> b bbar tau+tau-, using the data...
Genuine Correlations of Like-Sign Particles in Hadronic $Z^0$ Decays (2001)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, Anagnostou, G, ...
Correlations among hadrons with the same electric charge produced in Z0 decays are studied using the high statistics data collected from 1991 through 1995 with the OPAL detector at LEP. Normalized...
Search for Single Top Quark Production at LEP2 (2001)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, Anagnostou, G, ...
A search for single top quark production via flavour changing neutral currents (FCNC) was performed with data collected by the OPAL detector at the e+e- collider LEP. Approximately 600 pb-1 of data...
Measurement of the Hadronic Cross-Section for the Scattering of Two Virtual Photons at LEP (2001)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, Anagnostou, G, ...
The interaction of virtual photons is investigated using the reaction e+e- -> e+e- hadrons based on data taken by the OPAL experiment at e+e- centre-of-mass energies sqrt(s_ee)=189-209 GeV, for W>5...
Measurement of $Z/\gamma^{*}$ production in Compton scattering of quasi-real photons (2001)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, Anagnostou, G, ...
The process e+ e- -> e+ e- Z/gamma* is studied with the OPAL detector at LEP at a centre of mass energy of sqrt(s) = 189 GeV. The cross-section times the branching ratio of the Z/gamma* decaying into...
Search for Lepton Flavour Violation in $e^+e^-$ Collisions at $\sqrt{s}$ = 189 - 209 GeV (2001)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, Anagnostou, G, ...
We search for lepton flavour violating events (e mu, e tau and mu tau) that could be directly produced in e+e- annihilations, using the full available data sample collected with the OPAL detector at...
Measurement of the Branching Ratio for the Process $b \to \tau^{-}\overline{\nu}_{\tau}X$ (2001)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, Anagnostou, G, ...
The inclusive branching ratio for the process b -> tau nu X has been measured using hadronic Z decays collected by the OPAL experiment at LEP in the years 1992-2000. The result is: BR(b -> tau nu X)...
Angular Analysis of the Muon Pair Asymmetry at LEP 1 (2001)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, Anagnostou, G, ...
Data on muon pair production obtained by the OPAL collaboration at centre of mass energies near the Z peak are analysed. Small angular mismatches between the directions of the two muons are used to...
Measurement of |$V_{ub}$| using b hadron semileptonic decays (2001)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, Anagnostou, G, ...
The magnitude of the CKM matrix element Vub is determined by measuring the inclusive charmless semileptonic branching fraction of beauty hadrons at OPAL based on b -> Xu l nu event topology and...