White, J. S., Hinkov, V., Heslop, R. W., Lycett, R. J., Forgan, E. M., Bowell, C., ...
We report on small-angle neutron scattering (SANS) measurements of the magnetic vortex lattice (VL) in fully oxygenated YBa2Cu3O7. By using a carefully detwinned sample we largely suppress pinning to...
Jun, Y. C., Kekapture, R. D., White, J. S., Brongersma, M. L.
We theoretically investigate the spontaneous emission process of an optical, dipolar emitter in metal-dielectric-metal slab and slot waveguide structures. We find that both structures exhibit strong...
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...
Precision Neutral Current Asymmetry Parameter Measurements from the Tau Polarization at LEP (2001)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, Anagnostou, G, ...
Measurements of the tau lepton polarization and forward-backward polarization asymmetry near the Z resonance using the OPAL detector are described. The measurements are based on analyses of tau -> e...
Measurement of the Branching Ratio for $D_{s} \to \tau\nu_{\tau}$ Decays (2001)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, Anagnostou, G, ...
Using about 3.9 million hadronic Z decays from e+e- collisions recorded by the OPAL detector at LEP at centre-of-mass energies near MZ the branching ratio for the decay D_s -> tau nu_tau has been...
A Simultaneous Measurement of the QCD Colour Factors and the Strong Coupling (2001)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, Anagnostou, G, ...
Using data from e+e- annihilation into hadrons, taken with the OPAL detector at LEP at the Z pole between 1991 and 1995, we performed a simultaneous measurement of the colour factors of the...
A Search for a Narrow Radial Excitation of the $D^{*\pm}$ Meson (2001)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, Anagnostou, G, ...
A sample of 3.73 million hadronic Z decays, recorded with the OPAL detector at LEP in the years 1991-95, has been used to search for a narrow resonance corresponding to the decay of the D*'+/-(2629)...
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, Anagnostou, G, ...
A search for the Standard Model Higgs boson has been performed with the OPAL detector at LEP based on the full data sample collected at sqrt(s) = 192-209 GeV in 1999 and 2000, corresponding to an...
Thesis (Ph. D.)--Queen's University of Belfast, 2001.
Precise Determination of the Z Resonance Parameters at LEP: Zedometry (2000)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, Anagnostou, G, ...
This final analysis of hadronic and leptonic cross-sections and of leptonic forward-backward asymmetries in e+e- collisions with the OPAL detector makes use of the full LEP1 data sample comprising...
A Study of $B_{s}$ Meson Oscillation Using $D_{s}^{-}$-Lepton Correlations (2000)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, Anagnostou, G, ...
From data collected around the Z resonance by the OPAL detector at LEP a sample of Bs decays was obtained using Ds^-l^+ combinations, where the Ds^- was fully reconstructed in the phi pi-, K*0K- and...
Charged Multiplicities in Z Decays into u, d, and s Quarks (2000)
Abbiendi, G, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, Anagnostou, G, ...
About 4.4 million hadronic decays of Z bosons, recorded by the OPAL detector at LEP at a centre-of-mass energy of around sqrt(s) = 91.2 GeV, are used to determine the mean charged particle...
Abbiendi, G, Ackerstaff, K, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, ...
The rates are measured per hadronic Z decay for gluon splitting to bb(bar) quark pairs, g_bb, and of events containing two bb(bar) quark pairs, g_4b, using a sample of four-jet events selected from...
Abbiendi, G, Abbiendi, G, Ackerstaff, K, Ainsley, C, Alexander, Gideon, Allison, J, ...
From about 4 million hadronic Z decays recorded by the OPAL detector on and near to the Z resonance, we select a sample of more than 570000 inclusively reconstructed B mesons. Orbitally-excited...
Abbiendi, G, Ackerstaff, K, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, ...
The lifetime and oscillation frequency of the B0 meson has been measured using B0->D*+l-v decays recorded on the Z0 peak with the OPAL detector at LEP. The D*+ -> D0pi+ decays were reconstructed...
Abbiendi, G, Ackerstaff, K, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, ...
A measurement of triple gauge boson couplings is presented, based on W-pair data recorded by the OPAL detector at LEP during 1998 at a centre-of-mass energy of 189 GeV with an integrated luminosity...
Abbiendi, G, Ackerstaff, K, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, ...
From a data sample of 183 pb^-1 recorded at a center-of-mass energy of roots = 189 GeV with the OPAL detector at LEP, 3068 W-pair candidate events are selected. Assuming Standard Model W boson decay...
A Measurement of the Rate of Charm Production in W Decays (2000)
Abbiendi, G, Ackerstaff, K, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, ...
Using data recorded at centre-of-mass energies around 183 GeV and 189 GeV with the OPAL detector at LEP, the fundamental coupling of the charm quark to the W boson has been studied. The ratio Rc^W =...
Abbiendi, G, Ackerstaff, K, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, ...
Measurements are presented of the polarisation of W+W- boson pairs produced in e+e- collisions, and of CP-violating WWZ and WWGamma trilinear gauge couplings. The data were recorded by the OPAL...
A Study of One-Prong Tau Decays with a Charged Kaon (2000)
Abbiendi, G, Ackerstaff, K, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, ...
From an analysis of the ionisation energy loss of charged particles selected from 110326 e+e- -> tau+tau- candidates recorded by the OPAL detector at e+e- centre-of-mass energies near the Z0...
Measurement of the Mass and Width of the W Boson in $e^{+}e^{-}$ Collisions at 189 GeV (2000)
Abbiendi, G, Ackerstaff, K, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, ...
The mass and width of the W boson are determined in e+e- collisions at LEP using 183 pb^-1 of data recorded at a centre-of-mass energy roots=189 GeV with the OPAL detector. The invariant mass...
Two Higgs Doublet Model and Model Independent Interpretation of Neutral Higgs Boson Searches (2000)
Abbiendi, G, Ackerstaff, K, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, ...
Searches for the neutral Higgs bosons h0 and A0, are used to obtain limits on the Type II Two Higgs Doublet Model (2HDM(II)) with no CP-violation in the Higgs sector and no additional particles...
Abbiendi, G, Ackerstaff, K, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, ...
The inclusive production rate of phi mesons from the decay of b hadrons produced in Z0 decays was measured to be Br(b->phi+X) = 0.0282+-0.0013(stat.)+-0.0019(syst.), using data collected by the OPAL...
Abbiendi, G, Ackerstaff, K, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, ...
The data recorded at a centre-of-mass energy of 189GeV by the OPAL detector at LEP are used to search for trilinear couplings of the neutral gauge bosons in the process e+e- --> Z-gamma. The...
Multiplicities of $\pi^{0}$, $\eta$, $K^{0}$ and of charged particles in quark and gluon jets (2000)
Abbiendi, G, Ackerstaff, K, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, ...
We compared the multiplicities of pizero, eta, Kzero and of charged particles in quark and gluon jets in 3-jet events, as measured by the OPAL experiment at LEP. The comparisons were performed for...
Measurement of the Low-x Behaviour of the Photon Structure Function $F2-\gamma$ (2000)
Abbiendi, G, Ackerstaff, K, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, ...
The photon structure function F2-gamma(x,Q**2) has been measured using data taken by the OPAL detector at centre-of-mass energies of 91Gev, 183Gev and 189Gev, in Q**2 ranges of 1.5 to 30.0 GeV**2...
Abbiendi, G, Ackerstaff, K, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, ...
Searches for final states expected in models with light gravitinos have been performed, including experimental topologies with multi-leptons with missing energy, leptons and photons with missing...
A measurement of the $\tau$ mass and the first CPT test with $\tau$ leptons (2000)
Abbiendi, G, Ackerstaff, K, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, ...
We measure the mass of the tau lepton to be 1775.1+-1.6(stat)+-1.0(sys t.) MeV using tau pairs from Z0 decays. To test CPT invariance we compare the masses of the positively and negatively charged...
Photonic events with missing energy in $e^{+}e^{-}$ collisions at $\sqrt{s}=189 GeV$ (2000)
Abbiendi, G, Ackerstaff, K, Ainsley, C, Åkesson, P F, Alexander, Gideon, Allison, J, ...
Photonic events with large missing energy have been observed in e+e- collisions at a centre-of-mass energy of 189GeV using the OPAL detector at LEP. Results are presented for event topologies...
Z boson pair production in $e^{+}e^{-}$ collisions at $\sqrt{s}$ = 183 and 189 GeV (2000)
Abbiendi, G, Ackerstaff, K, Åkesson, P F, Alexander, Gideon, Allison, J, Anderson, K J, ...
A study of Z boson pair production in e+e- annihilation at center-of-mass energies near 183 GeV and 189 GeV is reported. Final states containing only leptons, (l+l-l+l- and l+l-nu nubar), quark and...
Measurement of |$V_{cb}$| using $\overline{B}^{0} \to D^{*+}l^{-}\overline{\nu}$ decays (2000)
Abbiendi, G, Ackerstaff, K, Åkesson, P F, Alexander, Gideon, Allison, J, Anderson, K J, ...
The magnitude of the Cabibbo-Kobayashi-Maskawa matrix element Vcb has been measured using B0 to D*l nu decays recorded on the Z0 peak using the OPAL detector at LEP. The D* to D0 pi+ decays were...
Transverse and Longitudinal Bose Einstein Correlations in hadronic $Z^0$ Decays (2000)
Abbiendi, G, Ackerstaff, K, Åkesson, P F, Alexander, Gideon, Allison, J, Anderson, K J, ...
Bose-Einstein correlations in pairs of identical charged pions produced in asample of 4.3 million Z0 hadronic decays are studied as a function of the threecomponents of the momentum difference,...
Abbiendi, G, Ackerstaff, K, Åkesson, P F, Alexander, Gideon, Allison, J, Anderson, K J, ...
The cross-section ratio Rb=sigma(e+e- to b-antib)/sigma(e+e- to q-antiq) andthe bottom and charm forward-backward asymmetries AFB^b and AFB^c are measuredusing event samples collected by the OPAL...
QCD studies with $e^{+}e^{-}$ annihilation data at 172-189 GeV (2000)
Abbiendi, G, Ackerstaff, K, Åkesson, P F, Alexander, Gideon, Allison, J, Anderson, K J, ...
We have studied hadronic events from e+e- annihilation data at centre-of-mass energies of sqrt{s}=172, 183 and 189 GeV. The total integrated luminosity of the three samples, measured with the OPAL...
Search for new Physics in rare B Decays (2000)
Abbiendi, G, Ackerstaff, K, Åkesson, P F, Alexander, Gideon, Allison, J, Anderson, K J, ...
A search for the decay B+- to K+-K+-pi-+ was performed using data collected by the OPAL detector at LEP. These decays are strongly suppressed in the Standard Model but could occur with a higher...
Leading Particle Production in Light Flavour Jets (2000)
Abbiendi, G, Ackerstaff, K, Åkesson, P F, Alexander, Gideon, Allison, J, Anderson, K J, ...
The energy distribution and type of the particle with the highest momentum in quark jets are determined for each of the five quark flavours making only minimal model assumptions. The analysis is...
Pfeifenschneider, P, Biebel, O, Movilla-Fernández, P A, Abbiendi, G, Ackerstaff, K, Åkesson, P F, ...
We employ data taken by the JADE and OPAL experiments for an integrated QCD study in hadronic e+e- annihilations at c.m.s. energies ranging from 35 GeV through 189 GeV. The study is based on...
Search for Unstable Heavy and Excited Leptons at LEP2 (2000)
Abbiendi, G, Ackerstaff, K, Åkesson, P F, Alexander, Gideon, Allison, J, Anderson, K J, ...
Searches for unstable neutral and charged heavy leptons, N and L+-, and for excited states of neutral and charged leptons, nu*, e*, mu*, and tau*, have been performed in e+e- collisions using data...
Abbiendi, G, Ackerstaff, K, Åkesson, P F, Alexander, Gideon, Allison, J, Anderson, K J, ...
Bose-Einstein correlations in pairs of charged kaons produced in a sample of 3.9 million hadronic Z0 decays have been measured with the OPAL experiment at LEP. Charged kaons were identified in the...
$\tau$ decays with neutral kaons (1999)
Abbiendi, G, Ackerstaff, K, Åkesson, P F, Alexander, Gideon, Allison, J, Anderson, K J, ...
The branching ratio of the tau lepton to a neutral K meson is measured from a sample of approximately 200,000 tau decays recorded by the OPAL detector at centre-of-mass energies near the Z0...
Abbiendi, G, Ackerstaff, K, Åkesson, P F, Alexander, Gideon, Allison, J, Anderson, K J, ...
The inclusive production of D*+- mesons in photon-photon collisions has been measured using the OPAL detector at LEP at e+e- centre-of-mass energies of 183 and 189GeV. The D* mesons are reconstructed...
Abbiendi, G, Ackerstaff, K, Åkesson, P F, Alexander, Gideon, Allison, J, Anderson, K J, ...
A study of W+W- events accompanied by hard photon radiation produced in e+e- collisions at LEP is presented. Events consistent with two on-shell W-bosons and an isolated photon are selected from...
Precision Luminosity for $Z^{0}$ Lineshape Measurements with a Silicon-Tungsten Calorimeter (1999)
Abbiendi, G, Ackerstaff, K, Alexander, Gideon, Allison, J, Anderson, K J, Anderson, S, ...
The measurement of small-angle Bhabha scattering is used to determine the luminosity at the OPAL interaction point for the LEP I data recorded between 1993 and 1995. The measurement is based on the...
Search for Chargino and Neutralino Production at $\sqrt{s} = 189 GeV$ at LEP (1999)
Abbiendi, G, Ackerstaff, K, Alexander, Gideon, Allison, J, Anderson, K J, Anderson, S, ...
A search for charginos and neutralinos, predicted by supersymmetric theories, is performed using a data sample of 182.1 pb-1 taken at a centre-of-mass energy of 189 GeV with the OPAL detector at LEP....
Abbiendi, G, Ackerstaff, K, Alexander, Gideon, Allison, J, Anderson, K J, Anderson, S, ...
A selection of di-lepton events with significant missing transverse momentum has been performed using a total data sample of 237.4 pb-1 at e+e- centre-of-mass energies of 183 GeV and 189 GeV. The...
A Study of Three-Prong $\tau$ Decays with Charged Kaons (1999)
Abbiendi, G, Ackerstaff, K, Alexander, Gideon, Allison, J, Anderson, K J, Anderson, S, ...
From an analysis of the ionisation energy loss of charged particles selected from a sample of 147926 e+e- -> tau+tau- candidates recorded in the OPAL detector at e+e- centre-of-mass energies near the...
Abbiendi, G, Ackerstaff, K, Alexander, Gideon, Allison, J, Anderson, K J, Anderson, S, ...
A search for pair-produced leptoquarks has been performed using a sample of e+e- collision events collected by the OPAL detector at LEP at e+e- centre-of-mass energies of about 183 GeV. The data...
Abbiendi, G, Ackerstaff, K, Alexander, Gideon, Allison, J, Anderson, K J, Anderson, S, ...
Cross-sections and angular distributions for hadronic and lepton pair final states in e+e- collisions at a centre-of-mass energy near 189 GeV, measured with the OPAL detector at LEP, are presented...
Search for Neutral Higgs Bosons in $e^{+}e^{-}$ Collisions at $\sqrt{s} \sim$ 189 GeV (1999)
Abbiendi, G, Ackerstaff, K, Alexander, Gideon, Allison, J, Anderson, K J, Anderson, S, ...
A search for neutral Higgs bosons has been performed with the OPAL detector at LEP, using approximately 170 pb-1 of e+e- collision data collected at sqrt(s)~189GeV. Searches have been performed for...
Abbiendi, G, Ackerstaff, K, Alexander, Gideon, Allison, J, Anderson, K J, Anderson, S, ...
The rate of secondary charm-quark-pair production has been measured in 4.4 million hadronic Z0 decays collected by OPAL. By selecting events with three jets and tagging charmed hadrons in the gluon...
Multi-photon production in $e^{+}e^{-}$ collisions at $\sqrt{s}$ = 189 GeV (1999)
Abbiendi, G, Ackerstaff, K, Alexander, Gideon, Allison, J, Anderson, K J, Anderson, S, ...
The process e+e- to 2 (or 3) gammas is studied using data recorded with the OPAL detector at LEP. The data sample taken at a centre-of-mass energy of 189 GeV corresponds to a total integrated...
A study of $B^{0}_{s}$ meson oscillation using hadronic $Z^{0}$ decays containing leptons (1999)
Abbiendi, G, Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, ...
A sample of Z decays containing b-flavoured hadrons is tagged using leptons, and events having precise proper time measurements are selected. These events are used to study Bs oscillations. using the...
Abbiendi, G, Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, ...
A search is described for the generic process e+e- to X Y, where X is a neutral heavy scalar boson decaying into a pair of photons, and Y is a neutral heavy boson (scalar or vector) decaying into a...
Abbiendi, G, Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, ...
The helicity density matrix elements rho[00] of rho(770)+- and omega(782) mesons produced in Z decays have been measured using the OPAL detector at LEP. Over the measured meson energy range, the...
Measurements of inclusive semileptonic branching fractions of b hadrons in $Z^{0}$ decays (1999)
Abbiendi, G, Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, ...
A measurement of inclusive semileptonic branching fractions of b hadrons produced in Z decays is presented. An enriched Z -> bbbar sample is obtained with a lifetime flavour-tagging technique. The...
Total Hadronic Cross-Section of Photon-Photon Interactions at LEP (1999)
Abbiendi, G, Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, ...
The total hadronic cross-section sigma_gg(W) for the interaction of real photons, gg->hadrons, is measured for gg centre-of-mass energies 10 e+e- hardrons, using a luminosity function for the photon...