Abulencia, A., Acosta, D., Adelman, J., Affolder, T., Akimoto, T., Albrow, M. G., ...
We present a measurement of R_B, the ratio of the branching fraction for the rare decay D0 -> K+ pi- to that for the Cabibbo-favored decay D0 -> K- pi+. Charge conjugate decays are implicitly...
Abulencia, A., Acosta, D., Adelman, J., Affolder, T., Akimoto, T., Albrow, M. G., ...
A measurement of the inclusive bottom jet cross section is presented for events containing a $Z$ boson in $p\bar{p}$ collisions at $\sqrt{s}=1.96$ TeV using the Collider Detector at Fermilab. $Z$...
Measurement of the $B_c^+$ Meson Lifetime Using the Decay Mode $B_c^+\toJ/\psie^+\nue$ (2006)
Abulencia, A., Acosta, D., Adelman, J., Affolder, T., Akimoto, T., Albrow, M. G., ...
We present a measurement of the B_c+ meson lifetime in the semileptonic decay mode Bc+ ->J/Psi e+ nu using the CDF II detector at the Fermilab Tevatron Collider. From a sample of about 360pb-1 p-pbar...
Abulencia, A., Acosta, D., Adelman, J., Affolder, T., Akimoto, T., Albrow, M. G., ...
We present a measurement of R_B, the ratio of the branching fraction for the rare decay D0 -> K+ pi- to that for the Cabibbo-favored decay D0 -> K- pi+. Charge conjugate decays are implicitly...
Abulencia, A., Acosta, D., Adelman, J., Affolder, T., Akimoto, T., Albrow, M. G., ...
A measurement of the inclusive bottom jet cross section is presented for events containing a $Z$ boson in $p\bar{p}$ collisions at $\sqrt{s}=1.96$ TeV using the Collider Detector at Fermilab. $Z$...
Measurement of the $B_c^+$ Meson Lifetime Using the Decay Mode $B_c^+\toJ/\psie^+\nue$ (2006)
Abulencia, A., Acosta, D., Adelman, J., Affolder, T., Akimoto, T., Albrow, M. G., ...
We present a measurement of the B_c+ meson lifetime in the semileptonic decay mode Bc+ ->J/Psi e+ nu using the CDF II detector at the Fermilab Tevatron Collider. From a sample of about 360pb-1 p-pbar...
Abulencia, A., Acosta, D., Adelman, J., Affolder, T., Akimoto, T., Albrow, M. G., ...
We present a measurement of R_B, the ratio of the branching fraction for the rare decay D0 -> K+ pi- to that for the Cabibbo-favored decay D0 -> K- pi+. Charge conjugate decays are implicitly...
Abulencia, A., Acosta, D., Adelman, J., Affolder, T., Akimoto, T., Albrow, M. G., ...
A measurement of the inclusive bottom jet cross section is presented for events containing a $Z$ boson in $p\bar{p}$ collisions at $\sqrt{s}=1.96$ TeV using the Collider Detector at Fermilab. $Z$...
Measurement of the $B_c^+$ Meson Lifetime Using the Decay Mode $B_c^+\toJ/\psie^+\nue$ (2006)
Abulencia, A., Acosta, D., Adelman, J., Affolder, T., Akimoto, T., Albrow, M. G., ...
We present a measurement of the B_c+ meson lifetime in the semileptonic decay mode Bc+ ->J/Psi e+ nu using the CDF II detector at the Fermilab Tevatron Collider. From a sample of about 360pb-1 p-pbar...
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 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...
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,...
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...
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...
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...
Search for R-Parity Violating Decays of Scalar Fermions at LEP (1999)
Abbiendi, G, Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, ...
A search for pair produced scalar fermions with couplings that violate R-parity has been performed using a data sample corresponding to an integrated luminosity of 56 pb-1 at a centre-of-mass energy...
Abbiendi, G, Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, ...
We present a test of the flavour independence of the strong coupling constant for charm and bottom quarks with respect to light (uds) quarks, based on a hadronic event sample obtained with the OPAL...
Search for Scalar Top and Scalar Bottom Quarks at $\sqrt{s}$ = 189 GeV at LEP (1999)
Abbiendi, G, Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, ...
Searches for a scalar top quark and a scalar bottom quark have been performed using a data sample of 182 pb-1 at a centre-of-mass energy of 189 GeV collected with the OPAL detector at LEP. No...
Experimental properties of gluon and quark jets from a point source (1999)
Abbiendi, G, Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, ...
Gluon jets are identified in hadronic Z0 decays as all the particles in a hemisphere opposite to a hemisphere containing two tagged quark jets. Gluon jets defined in this manner are equivalent to...
Intermittency and correlations in hadronic $Z^0$ decays (1999)
Abbiendi, G, Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, ...
A multidimensional study of local multiplicity fluctuations and multiparticle correlations of hadrons produced in Z decays is performed. The study is based on the data sample of more than 4 million...
Measurements of the QED Structure of the Photon (1999)
Abbiendi, G, Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, ...
The structure of both quasi-real and highly virtual photons is investigated using the reaction e+e- -> e+e-mu+mu-, proceeding via the exchange of two photons. The results are based on the complete...
Searches for R-Parity Violating Decays of Gauginos at 183 GeV at LEP (1999)
Abbiendi, G, Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, ...
Searches for pair-produced charginos and neutralinos with R-parity violating decays have been performed using a data sample corresponding to an integrated luminosity of 56 pb-1 collected with the...
Measurement of the W Mass and Width in $e^{+}e^{-}$ Collisions at 183 GeV (1999)
Abbiendi, G, Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, ...
Using a data sample of 57 pb-1 recorded at a centre-of-mass energy of 183 GeV with the Opal detector at LEP, 282 W+W- -> qqqq and 300 W+W- -> qqlnu candidate events are used to obtain a measurement...
Colour reconnection studies in $e^{+}e^{-} \to W^{+}W^{-}$ at $\sqrt{s}$=183 GeV (1999)
Abbiendi, G, Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, ...
The predicted effects of final state interactions such as colour reconnection are investigated by measuring properties of hadronic decays of W bosons, recorded at a centre-of-mass energy of...
Abbiendi, G, Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, ...
The lifetimes of the B+ and B0 mesons, and their ratio, have been measured in the OPAL experiment using 2.4 million hadronic Z0 decays recorded at LEP. Z0 -> b bbar decays were tagged using displaced...
Search for Baryon and Lepton Number Violating $Z^0$ Decays (1999)
Abbiendi, G, Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, ...
Using data collected with the OPAL detector at LEP, we have searched for the processes e+e- -> Z0 -> p e-, p mu- and the charge conjugate final-states. These would violate the conservation of the...
Abbiendi, G, Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, ...
The product branching ratio, f(b->Lambda_b).BR(Lambda_b->Lambda X), where Lambda_b denotes any weakly-decaying b-baryon, has been measured using the OPAL detector at LEP. Lambda_b are selected by the...
A measurement of the $\tau^{-} \to e^{-} \overline{\nu}_{e}\nu_{\tau}$ branching ratio (1998)
Abbiendi, G, Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, ...
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 identified from a...
$W^{+}W^{-}$ production and triple gauge boson couplings at LEP energies up to 183 GeV (1998)
Abbiendi, G, Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, ...
A study of W-pair production in e+e- annihilations at Lep2 is presented, based on 877 W+W- candidates corresponding to an integrated luminosity of 57 pb-1 at sqrt(s) = 183 GeV. Assuming that the...
Search for Higgs Bosons in $e^{+} e^{-}$ Collisions at 183 GeV (1998)
Abbiendi, G, Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, ...
The data collected by the OPAL experiment at sqrts=183 GeV were used to search for Higgs bosons which are predicted by the Standard Model and various extensions, such as general models with two Higgs...
Bose-Einstein Correlations in $e^{+} e^{-} \to W^{+}W^{-}$ at 172 and 183 GeV (1998)
Abbiendi, G, Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, ...
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 samples are...
A Measurement of $R_{b}$ using a Double Tagging Method (1998)
Abbiendi, G, Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, ...
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 tagged using...
Abbiendi, G, Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, ...
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. Results are...
Abbiendi, G, Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, ...
The inclusive charm hadron semileptonic branching fractions B(c to e) and B(c to mu) in Z to ccbar events have been determined using 4.4 million hadronic Z decays collected with the OPAL detector at...
Search for Chargino and Neutralino Production at $\sqrt{s}$ = 181-184 GeV at LEP (1998)
Abbiendi, G, Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, ...
A search for charginos and neutralinos, predicted by supersymmetric theories, has been performed using a data sample of 57 pb-1 at centre-of-mass energies of 181-184 GeV taken with the OPAL detector...
Abbiendi, G, Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, ...
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 quantified by the...
Abbiendi, G, Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, ...
A selection of di-lepton events with significant missing transverse momentum has been performed using a total data sample of 77.0 pb-1 at e+e- centre-of-mass energies of 161 GeV, 172 GeV and 183 GeV....
Abbiendi, G, Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, ...
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 investigated in the...
First measurement of $Z/\gamma^{*}$ production in Compton scattering of quasi-real photons (1998)
Abbiendi, G, Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, ...
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 final state electrons...
Di-Jet Production in Photon-Photon Collisions at $\sqrt{s}_{ee}$ = 161 and 172 GeV (1998)
Abbiendi, G, Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, ...
Di-jet production is studied in collisions of quasi-real photons radiated by the LEP beams at e+e- centre-of-mass energies 161 and 172 GeV. The jets are reconstructed using a cone jet finding...
Abbiendi, G, Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, ...
Cross-sections for hadronic, b-bbar and lepton pair final states in e+e- collisions at sqrt(s) = 183 GeV, measured with the OPAL detector at LEP, are presented and compared with the predictions of...
Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, Anderson, S, ...
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 Operator Product...
Measurement of the Michel Parameters in Leptonic Tau Decays (1998)
Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, Anderson, S, ...
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 leptons and from their...
Search for Higgs bosons and new particles decaying into two photons at $\sqrt{s}$ = 183 GeV (1998)
Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, Anderson, S, ...
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 average center-of-mass...
Multi-photon production in $e^{+}e^{-}$ collisions at $\sqrt{s}$= 183 GeV (1998)
Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, Anderson, S, ...
The process e+e- to gamma gamma (gamma) is studied using data recorded with the OPAL detector at LEP. The data sample corresponds to a total integrated luminosity of 56.2 pb-1 taken at a...
Inclusive production of charged hadrons and $K_{s}^{0}$ mesons in photon-photon collisions (1998)
Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, Anderson, S, ...
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-mass energies of 161...
Measurement of the average polarization of b baryons in hadronic $Z^0$ decays (1998)
Abbiendi, G, Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, ...
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 expected to be...
Measurement of Tau Branching Ratios to Five Charged Hadrons (1998)
Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, Anderson, S, ...
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- centre-of-mass energies...
Measurements of flavour dependent fragmentation functions in $Z^{0} \to q\overline{q}$ events (1998)
Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, Anderson, S, ...
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 results are based on...
Bose-Einstein correlations of three charged pions in hadronic $Z^{0}$ decays (1998)
Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, Anderson, S, ...
Bose-Einstein Correlations (BEC) of three identical charged pions were studied in 4 x 10^6 hadronic Z^0 decays recorded with the OPAL detector at LEP. The genuine three-pion correlations, corrected...
An upper limit for the $\tau$-neutrino mass from $\tau \to 5\pi^{\pm} \nu_{\tau}$ decays (1998)
Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, Anderson, S, ...
An upper limit for the tau-neutrino mass has been determined from the decay tau -> 5pi+- \nu_tau using data collected with the OPAL detector from 1991 to 1995 in e+e- collisions at \sqrt{s} ~ M_Z. A...
Photon and light meson production in hadronic $Z^{0}$ decays (1998)
Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, Anderson, S, ...
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 light mesons covered...
Production of $K^{0}_{S}$ and $\Lambda$ in Quark and Gluon Jets from $Z^{0}$ Decay (1998)
Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, Anderson, S, ...
The production of K^0_S mesons and Lambda baryons in quark and gluon jets has been investigated using two complementary techniques. In the first approach, which provides high statistical accuracy,...
An upper limit on the anomalous magnetic moment of the $\tau$ lepton (1998)
Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, Anderson, S, ...
Using radiative Z^0 -> \tau^+ \tau^- \gamma events collected with the OPAL detector at LEP at \sqrt{s}=M_Z during 1990-95, a direct study of the electromagnetic current at the \tau\gamma vertex has...
A search for neutral Higgs bosons in the MSSM and models with two scalar field doublets (1998)
Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, Anderson, S, ...
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 (MSSM). The search in...
Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, Anderson, S, ...
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 reported by the OPAL...
Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, Anderson, S, ...
Events with four distinct jets from e^+e^- collisions, collected by the OPAL detector at centre-of-mass energies between 130 and 184 GeV, are analysed for a peak in the sum of dijet masses. This...
Production of $f_{0}(980), f_{2}(1270)$ and $\phi(1020)$ in hadronic $Z^{0}$ decay (1998)
Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, Anderson, S, ...
Inclusive production of the f_0(980), f_2(1270) and \phi(1020) resonances has been studied in a sample of 4.3 million hadronic Z^0 decays from the OPAL experiment at LEP. A coupled channel analysis...
Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, Anderson, S, ...
In e^+e^- collisions at centre-of-mass energies around 91 GeV, D^*0 mesons have been reconstructed using data collected with the OPAL detector at LEP. The hadronisation fraction has been measured to...
Measurements of the $B^{0}_s$ and $\Lambda^{0}_b$ lifetimes (1998)
Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, Anderson, S, ...
This paper presents updated measurements of the lifetimes of the B^0_s meson and the \Lambda_b baryon using 4.4 million hadronic Z^0 decays recorded by the OPAL detector at LEP from 1990 to 1995. A...
Search for charged Higgs bosons in $e^+ e^-$ collisions at $\sqrt{s}$ = 130-172 GeV (1998)
Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, Anderson, S, ...
A search is described to detect charged Higgs bosons via the process e^+e^- -> H^+H^-, using data collected by the OPAL detector at center-of-mass energies of 130-172 GeV with a total integrated...
Measurement of the one-prong hadronic $\tau$ branching ratios at LEP (1998)
Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, Anderson, S, ...
The branching ratios of the \tau^- -> h^- \nu_\tau, \tau^- -> h^- \pi^0 1991-1995 data recorded with the OPAL detector at LEP. These branching ratios are measured simultaneously using three selection...
Investigation of CP violation in $B^{0} \to J/\psi K_{s}^{0}$ decays at LEP (1998)
Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, Anderson, S, ...
An investigation of CP violation was performed using a total of 24 candidates for B^0 -> J/psi K^0_S decay, with a purity of about 60%. These events were selected from 4.4 million hadronic Z^0 decays...
Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, Anderson, S, ...
Photonic events with large missing energy have been observed in e+e- collisions at centre-of-mass energies of 130, 136, 161 and 172 GeV using the OPAL detector at LEP. Results are presented based on...
Search for the $B_c$ meson in hadronic $Z^0$ decays (1997)
Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, Anderson, S, ...
A search for decays of the B_c meson was performed using data collected from 1990-1995 with the OPAL detector on or near the Z peak at LEP. The decay channels B_c^+ -> J/psi pi^+, B_c^+ -> J/psi...