Scientific Commons: P. G. Bright-Thomas

Search for the Standard Model Higgs Boson in $e^{+}e^{-}$ Collisions at $\sqrt{s}$ = 192-209 GeV (2001)

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...

Measurement of the B$^0$ and B$^+$ meson lifetimes with fully reconstructed hadronic final states (2001)

Aubert, B., Boutigny, D., Gaillard, J.M., Hicheur, A., Karyotakis, Y., Lees, J.P., ...

The B0 and B+ meson lifetimes have been measured in e+e- annihilation data collected in 1999 and 2000 with the BABAR detector at center-of-mass energies near the Upsilon(4S) resonance. Events are...

Measurement of the decays $B\to\phi K$ and $B\to\phi K*$ (2001)

Aubert, B., Boutigny, D., Gaillard, J.M., Hicheur, A., Karyotakis, Y., Lees, J.P., ...

We have observed the decays B-->phi K and phi K^* in a sample of over 45 million B mesons collected with the BABAR detector at the PEP-II collider. The measured branching fractions are BF(B^+ --> phi...

Measurement of $J/\psi$ production in continuum $e^{+}e^{-}$ annihilations near $\sqrt{s}=10.6-GeV$ (2001)

Aubert, B., Boutigny, D., Gaillard, J.M., Hicheur, A., Karyotakis, Y., Lees, J.P., ...

The production of $J/\psi$ mesons in continuum $e^+e^-$ annihilations has been studied with the BABAR detector at energies near the $\Upsilon(4S)$ resonance, approximately 10.6 GeV. The mesons are...

Measurement of the B$^0$ and B$^+$ meson lifetimes with fully reconstructed hadronic final states (2001)

Aubert, B., Boutigny, D., Gaillard, J.M., Hicheur, A., Karyotakis, Y., Lees, J.P., ...

The B0 and B+ meson lifetimes have been measured in e+e- annihilation data collected in 1999 and 2000 with the BABAR detector at center-of-mass energies near the Upsilon(4S) resonance. Events are...

Measurement of the decays $B\to\phi K$ and $B\to\phi K*$ (2001)

Aubert, B., Boutigny, D., Gaillard, J.M., Hicheur, A., Karyotakis, Y., Lees, J.P., ...

We have observed the decays B-->phi K and phi K^* in a sample of over 45 million B mesons collected with the BABAR detector at the PEP-II collider. The measured branching fractions are BF(B^+ --> phi...

Measurement of $J/\psi$ production in continuum $e^{+}e^{-}$ annihilations near $\sqrt{s}=10.6-GeV$ (2001)

Aubert, B., Boutigny, D., Gaillard, J.M., Hicheur, A., Karyotakis, Y., Lees, J.P., ...

The production of $J/\psi$ mesons in continuum $e^+e^-$ annihilations has been studied with the BABAR detector at energies near the $\Upsilon(4S)$ resonance, approximately 10.6 GeV. The mesons are...

Measurement of the B$^0$ and B$^+$ meson lifetimes with fully reconstructed hadronic final states (2001)

Aubert, B., Boutigny, D., Gaillard, J.M., Hicheur, A., Karyotakis, Y., Lees, J.P., ...

The B0 and B+ meson lifetimes have been measured in e+e- annihilation data collected in 1999 and 2000 with the BABAR detector at center-of-mass energies near the Upsilon(4S) resonance. Events are...

Measurement of the decays $B\to\phi K$ and $B\to\phi K*$ (2001)

Aubert, B., Boutigny, D., Gaillard, J.M., Hicheur, A., Karyotakis, Y., Lees, J.P., ...

We have observed the decays B-->phi K and phi K^* in a sample of over 45 million B mesons collected with the BABAR detector at the PEP-II collider. The measured branching fractions are BF(B^+ --> phi...

Measurement of $J/\psi$ production in continuum $e^{+}e^{-}$ annihilations near $\sqrt{s}=10.6-GeV$ (2001)

Aubert, B., Boutigny, D., Gaillard, J.M., Hicheur, A., Karyotakis, Y., Lees, J.P., ...

The production of $J/\psi$ mesons in continuum $e^+e^-$ annihilations has been studied with the BABAR detector at energies near the $\Upsilon(4S)$ resonance, approximately 10.6 GeV. The mesons are...

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...

Production rate of $b\overline{b}$ quark pairs from gluons and $b\overline{b}b\overline{b}$ events in hadronic Z decays (2000)

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...

Investigation of the Decay of Orbitally-Excited B Mesons and First Measurement of the Branching Ratio $BR(B*_{J} \to B*\pi(X))$ (2000)

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...

Measurement of the $B^0$ Lifetime and Oscillation Frequency using $\overline{B}^{0} \to D^{*+}l^{-}\overline{\nu}$ decays (2000)

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...

Measurement of triple gauge boson couplings from $W^{+}W^{-}$ production at LEP energies up to 189 GeV (2000)

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...

$W^{+}W^{-}$ Production Cross Section and W Branching Fractions in $e^{+}e^{-}$ Collisions at 189 GeV (2000)

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 =...

Measurement of W boson polarisations and CP-violating triple gauge couplings from $W^{+}W^{-}$ production at LEP (2000)

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...

First Measurement of the Inclusive Branching Ratio of b Hadrons $\to \phi$ Mesons in $Z^{0}$ Decays (2000)

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...

Search for Trilinear Neutral Gauge Boson Couplings in $Z-\gamma$ production at $\sqrt{s}$=189 GeV at LEP (2000)

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...

Searches for prompt light gravitino signatures in $e^{+}e^{-}$ Collisions at $\sqrt{s}$ = 189 GeV (2000)

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,...

Measurements of $R_{b}$, $A_{FB}^{b}$ and $A_{FB}^{c}$ in $e^{+}e^{-}$ Collisions at 130-189 GeV (2000)

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...

QCD analyses and determinations of $\alpha_{s}$ in $e^{+}e^{-}$ annihilation at energies between 35 and 189 GeV (2000)

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...

Bose-Einstein correlations in $K^{\pm}K^{\pm}$ pairs from $Z^{0}$ decays into two hadronic jets (2000)

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...

Inclusive production of $D^{*\pm}$ mesons in photon-photon collisions at $\sqrt{s}_{ee}$= 183 and 189 GeV and a first measurement of $F^{\gamma}_{2,c}$ (1999)

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...

Measurement of the $W^{+}W^{-} \gamma$ Cross-section and First direct Limits on Anomalous Electroweak Quartic Gauge Couplings (1999)

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....

Search for Anomalous Production of Acoplanar Di-lepton Events in $e^{+}e^{-}$ Collisions at $\sqrt{s}$=183 and 189 GeV (1999)

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...

Measurement of the Z Resonance Parameters at LEP (1999)

Barate, R, Décamp, D, Ghez, P, Goy, C, Lees, J P, Lucotte, A, ...

The properties of the Z resonance are measured from the analysis of 4.5 million Z decays into fermion pairs collected with the \Aleph\ detector at L EP. The data are consistent with lepton...

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...

Search for pair-produced leptoquarks in $e^{+}e^{-}$ interactions at $\sqrt{s} \simeq$ 183 GeV (1999)

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...

Tests of the Standard Model and Constraints on New Physics from Measurements of Fermion-pair Production at 189 GeV at LEP (1999)

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...

Measurement of the Production Rate of Charm Quark Pairs from Gluons in Hadronic $Z^{0}$ Decays (1999)

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...

Search for Higgs Bosons and Other Massive States decaying into two Photons in $e^{+}e^{-}$ Collisions at 189 GeV (1999)

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...

A Study of Spin Alignment of $\rho(770)^{\pm}$ and $\omega(782)$ Mesons in Hadronic $Z^{0}$ Decays (1999)

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...

Test of the Flavour Independence of $\alpha_{s}$ using Next-to-Leading Order Calculations for Heavy Quarks (1999)

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...

Measurement of the $B^{+}$ and $B^{0}$ lifetimes and search for CP(T) violation using reconstructed secondary vertices (1999)

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...

Evaluation of the LEP Centre-of-Mass Energy Above the W-Pair Production Threshold (1999)

Blondel, A, Böge, M, Bravin, Enrico, Bright-Thomas, P G, Camporesi, T, Dehning, Bernd, ...

Knowledge of the centre-of-mass energy at LEP2 is of primary importance to set the absolute energy scale for the measurement of the W-boson mass. The beam energy above 80 GeV is derived from...

A Measurement of the Product Branching Ratio $f(b \to \Lambda_{b}).BR (\Lambda_{b} \to \Lambda X)$ in $Z^{0}$ Decays (1998)

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...

Search for Anomalous Photonic Events with Missing Energy in $e^{+} e^{-}$ Collisions at $\sqrt{s}$ = 130, 136 and 183 GeV (1998)

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...

Measurement of the Semileptonic Branching Ratio of Charm Hadrons Produced in $Z^{0} \to c\bar{c}$ Decays (1998)

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...

Measurement of the longitudinal cross-section using the direction of the thrust axis in hadronic events at LEP (1998)

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...

Search for Acoplanar Lepton Pair Events in $e^{+}e^{-}$ Collisions at $\sqrt{s}$ = 161, 172 and 183 GeV (1998)

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....

A Study of Parton Fragmentation in Hadronic $Z^{0}$ Decays Using $\Lambda \overline\Lambda$ Correlations (1998)

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...

Tests of the Standard Model and constraints on new physics from measurements of fermion-pair production at 183 GeV at LEP (1998)

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...

Measurement of the Strong Coupling Constant $\alpha_s$ and the Vector and Axial-Vector Spectral Functions in Hadronic Tau Decays (1998)

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...

Study of $D^{0}-\overline{D}^{0}$ mixing and $D^{0}$ doubly-Cabibbo-suppressed decays (1998)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

Using a sample of four million hadronic Z events collected in ALEPH from 1991 to 1995, the decays D^{*+} --> D^0 pi_{s}^+, with D^0 decaying to K^- pi^+ or to K^+ pi^-, are studied. The relative br...

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...

Search for $B^{0}_{s}$ oscillations using inclusive lepton events (1998)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

A search for Bs oscillations is performed using a sample of semileptonic b-hadron decays collected by the ALEPH experiment during 1991-1995. Compared to previous inclusive lepton analyses, the prop...

The forward-backward asymmetry for charm quarks at the Z (1998)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

From this analysis, a value of the effective electroweak mixing angle $\sin^2 \theta^{\mathrm eff}_W = 0.2321 \pm 0.0016$ is extracted.

A measurement of the gluon splitting rate into $b\overline{b}$ pairs in hadronic Z decays (1998)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

A measurement of the fraction of hadronic Z decays in which a gluon splits into a $b \bar{b}$ pair, \gbb, is presented using data collected by {\t extsc ALEPH} from 1992 to 1995 at the Z resonance....

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...

Scalar quark searches in $e^+ e^-$ collisions at $\sqrt{s}$ = 181-184 GeV (1998)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Jézéquel, S, ...

Searches for scalar top, scalar bottom and degenerate scalar quarks have been performed with data collected with the ALEPH detector at LEP. The data sample consists of 57~$\mathrm{pb}^{-1}$ taken at...

Search for sleptons in $e^+ e^-$ collisions at centre-of-mass energies up to 184 GeV (1998)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Jézéquel, S, ...

The data collected by the ALEPH experiment at LEP at centre-of-mass energies around 183 GeV are analysed to search for sleptons, the partners of leptons in supersymmetric theories. The previously pu...

Determination of $|V_{ub}|$ from the measurement of the inclusive charmless semileptonic branching ratio of b hadrons (1998)

Barate, R, Abbaneo, D, Affholderbach, K, Ajaltouni, Ziad J, Alemany, R, Aleppo, M, ...

From a study of the kinematic properties of the final state produced in the semileptonic decays b-->X l nu, the inclusive charmless semileptonic branching ratio of b hadrons is measured. With a sam...

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,...

Single- and multi-photon production in $e^{+}e^{-}$ collisions at a centre-of-mass energy of 183 GeV (1998)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Jézéquel, S, ...

The production of final states involving one or more energetic photons from e+e- collisions is studied in a sample of 58.5 pb-1 of data recorded at a centre-of-mass energy of 183 GeV by the ALEPH...

Measurement of the fraction of hadronic Z decays into charm quark pairs (1998)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

A measurement of the inclusive $b \rightarrow s \gamma$ branching ratio (1998)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

The flavour changing neutral current decay b -> s gamma has been detected in hadronic Z decays collected by ALEPH at LEP. The signal is isolated in lifetime-tagged b-bbar events by the presence of a...

Determination of $A^{b}_{FB}$ using Jet Charge Measurements in Z Decays (1998)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

An improved measurement of the forward-backward asymmetry in Z-> b b-bar decays is presented, based on a sample of 4.1 million hadronic Z decays collected by Aleph between 1991 and 1995. Data are a...

Calibration of centre-of-mass energies at LEP1 for precise measurements of Z properties (1998)

Assmann, R W, Böge, M, Billen, R, Blondel, A, Bravin, Enrico, Bright-Thomas, P G, ...

The determination of the centre-of-mass energies from the LEP1 data for 1993, 1994 and 1995 is presented. Accurate knowledge of these energies is crucial in the measurement of the Z resonance param...

Observation of doubly-charmed B decays at LEP (1998)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

A search for doubly-charmed B decays with both charmed mesons reconstructed is performed, using about 3.8 million hadronic Z decays recorded with the ALEPH detector at LEP. A clear signal is observed...

Search for evidence of compositeness at LEP I (1998)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

Extensive searches for evidence of compositeness of quarks and leptons have been made using the full set of ALEPH data from LEP running at the Z peak. They include searches for radiative and weak...

Measurement of the W mass by direct reconstruction in $e^+ e^-$ collisions at 172 GeV (1998)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

The mass of the W boson is obtained from reconstructed invariant mass distributions in W-pair events. The sample of W pairs is selected from 10.65~pb$^{-1}$ collected with the ALEPH detector at a...

Measurement of triple gauge-boson couplings at 172 GeV (1998)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

The triple gauge-boson couplings, Awp, Aw and Abp, have been measured using 34 semileptonically and 54 hadronically decaying WW candidate events. The events were selected in the data recorded during...

$K^{0}_{S}$ production in $\tau$ decays (1998)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

From a sample of about 160k $\mbox{Z}\!\!\to\!\!\tau^+\tau^-$ candidates collected with the ALEPH detector at LEP between 1991 and 1995, $\tau$ lepton decays involving $K^0_S\!\to\!\pi^+\pi^-$ are...

Measurements of the structure of quark and gluon jets in hadronic Z decays (1998)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

An experimental investigation of the structure of identified quark and gluon jets is presented. Observables related to both the global and internal structure of jets are measured; this allows for...

Resonant structure and flavour tagging in the $B\pi^{\pm}$ system using fully reconstructed $B$ decays (1998)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

Starting from a sample of four million hadronic $Z$ decays collected with the ALEPH detector at LEP, 404 charged and neutral $B$ mesons are fully reconstructed and used to look for resonant structure...

Measurement of the spectral functions of axial-vector hadronic $\tau$ decays and determination of $\alpha_{s}(M^2_\tau)$ (1998)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

An analysis based on 124000 selected tau pairs recorded by the ALEPH detector at LEP provides the vector (V) and axial-vector (A) spectral functions of hadronic tau decays together with their total...

Study of $B^0_s$ oscillations and lifetime using fully reconstructed $D^-_s$ decays (1998)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

A search for B0s oscillations is performed using approximately 4 million Z --> qqbar events collected by the ALEPH experiment during 1991-1995. B0s candidates are partially reconstructed by combining...

Four-jet final state production in $e^+ e^-$ collisions at centre-of-mass energies ranging from 130 to 184 GeV (1998)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

The four jet topology is analysed in the ALEPH data taken between November 1995 and November 1997, at centre-of-mass energies ranging from 130 to 184 GeV. While an unexpected accumulation of events...

A measurement of the semileptonic branching ratio BR(b-baryon $\rightarrow p l\overline{\nu}X$) and a study of inclusive $\pi^{\pm}$, $K^{\pm}$, ($p,\overline{p}$) production in Z decays (1998)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

Inclusive pi^+/-, K^+/- (p,pbar) production is investigated using data recorded by the ALEPH detector between 1992 and 1994. The momentum spectra and multiplicities are measured separately in Z...

Search for supersymmetry with a dominant R-parity violating $LL\overline{E}$ coupling in $e^+ e^-$ collisions at centre-of-mass energies of 130 GeV to 172 GeV (1997)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

A search for pair-production of supersymmetric particles under the assumption that R-parity is violated via a dominant LLE coupling has been performed using the data collected by ALEPH at...

An upper limit on the $\tau$ neutrino mass from three- and five-prong tau decays (1997)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

A bound on the tau neutrino mass is established using the data collected from 1991 to 1995 at Ecm = M(Z) with the ALEPH detector. Two separate limits are derived by fitting the distribution of...

Searches for charginos and neutralinos in $e^+ e^-$ collisions at $\sqrt{s}$ = 161 and 172 GeV (1997)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

The data recorded by the ALEPH detector at centre-of-mass energies of 161, 170, and 172 GeV are analysed for signals of chargino and neutralino production. No evidence of a signal is found, although...

Search for charged Higgs bosons in $e^+ e^-$ collisions at centre-of-mass energies from 130 to 172 GeV (1997)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

The data collected at centre-of-mass energies ranging from 130 to 172 GeV by ALEPH at LEP, corresponding to an integrated luminosity of 27.5 pb-1, are analysed in a search for pair-produced charged...

Searches for supersymmetry in the photon(s) plus missing energy channels at $\sqrt{s}$ = 161 GeV and 172 GeV (1997)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

Searches for supersymmetric particles in channels with one or more photons and missing energy have been performed with data collected by the ALEPH detector at LEP. The data consist of 11.1 \pb\ at...

Measurement of the b baryon lifetime and branching fractions in Z decays (1997)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

Using approximately 4 million hadronic Z decays recorded with the Aleph detector from 1991 through 1995, the lifetime of the b baryon is measured with three independent methods. From the impact...

Updated measurement of the $\tau$ lepton lifetime (1997)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

A new measurement of the mean lifetime of the tau lepton is presented. Three different analysis methods are applied to a sample of 90000 tau pairs, collected in 1993 and 1994 with the ALEPH detector...

Measurement of the W-pair cross section in $e^+ e^-$ collisions at 172 GeV (1997)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

The e+e- --> W+W- cross section is measured in a data sample collected by ALEPH at a mean centre--of--mass energy of 172.09 GEV, corresponding to an integrated luminosity of 10.65 pb-1. Cross...

Searches for scalar top and scalar bottom quarks at LEP2 (1997)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

Searches for scalar top and bottom quarks have been performed with data collected by the ALEPH detector at LEP. The data sample consists of 21.7 pb^-1 taken at sqrt{s} = 161, 170, and 172~GeV and 5.7...

Search for the neutral Higgs bosons of the MSSM in $e^+ e^-$ collisions at $\sqrt{s}$ from 130 to 172 GeV (1997)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

The process e+e- --> h A is used to search for the Higgs bosons of the Minimal Supersymmetric Standard Model (MSSM), in the bbbb and tautaubb final states. The search is performed in the data...

Three-prong $\tau$ decays with charged kaons (1997)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

Final states with charged kaons in three-prong $\tau$ decays are studied by exploiting the particle identification from the dE/dx measurement. The results are based on a sample of about $1.6\times...

Search for the standard model Higgs boson in $e^+ e^-$ collisions at $\sqrt{s}$=161, 170 and 172 GeV (1997)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

The reaction e+e- -> HZ is used to search for the Standard Model Higgs boson. The data sample consists of integrated luminosities of 10.9pb-1 1.1pb-1 and 9.5pb-1 collected by the ALEPH experiment at...

Search for sleptons in $e^+ e^-$ collisions at centre-of-mass energies of 161 GeV and 172 GeV (1997)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

The data recorded by the ALEPH experiment at LEP at centre-of-mass energies of 161 GeV and 172 GeV were analysed to search for sleptons, the supersymmetric partners of leptons. No evidence for the...

Measurement of the transverse spin correlations in the decay $Z \rightarrow \tau^+\tau^-$ (1997)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

For tau leptons produced in e^+e^- -> tau^+ tau^- interactions there are, in addition to the longitudinal spin correlations, two independent transverse spin correlations associated with the...

Search for pair-production of long-lived heavy charged particles in $e^+ e^-$ annihilation (1997)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

A search for pair-production of long-lived, heavy, singly-charged particles has been performed with data collected by the ALEPH detector at a centre-of-mass energy of 172 GeV. Data at \sqrt{s} = 161,...

Search for the $B_{c}$ meson in hadronic Z decays (1997)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

A search for the Bc meson decaying into the channels J/psi pi+ and J/psi l nu (l = e or mu) is performed in a sample of 3.9 million hadronic Z decays collected by the ALEPH detector. This search...

Measurement of the branching fraction for $D^{0} \rightarrow K^{-}\pi^{+}$ (1997)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

The branching fraction for D0 -> K- pi+ is measured with the statistics collected by ALEPH from 1991 to 1994. The method is based on the comparison between the rate for the reconstructed D*+ -> D0...

Measurement of the W mass in $e^{+}e^{-}$ collisions at production threshold (1997)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

In June 1996, the LEP centre-of-mass energy was raised to 161 GeV. Pair production of W bosons in e+e- collisions was observed for the first time by the LEP experiments. An integrated luminosity of...

A Measurement of $R_b$ using a Lifetime-Mass Tag (1997)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

ALEPH's published measurement of $R_b$ using a lifetime tag, is updated using the full LEP~1 data sample. Considerable effort has been devoted to understanding systematic effects. Charm background is...

A Measurement of $R_b$ using Mutually Exclusive Tags (1997)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

A measurement of $R_b$ using five mutually exclusive hemisphere tags has been pe rformed by ALEPH using the full LEP1 statistics. Three tags are designed to sele ct the decay of the $Z^0$ to $b$...

Measurement of the spectral functions of vector current hadronic $\tau$ decays (1997)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

A measurement of the spectral functions of non-strange tau vector current final states is presented, using 124,358 tau pairs recorded by the ALEPH detector at LEP during the years 1991 to 1994. The...

Measurement of the $\tau$ Lepton Lifetime with the Three-dimensional Impact Parameter Method (1997)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

A new method is presented for the measurement of the mean $\tau$ lepton lifetime using events in which $\tau$'s are pair-produced and both $\tau$'s decay to hadrons and $\nu_\tau$. Based on the...

Study of the muon-pair production at centre-of-mass energies from 20 to 136 GeV with the ALEPH detector (1997)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

The total cross section and the forward-backward asymmetry for the process $e^+ e^- \rightarrow \mu^+ \mu^- (n \gamma)$ are measured in the energy range 20-136 GeV by reconstructing the effective...

A measurement of the QCD colour factors and a limit on the light gluino (1997)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

Using data collected from 1992 to 1995 with the ALEPH detector at LEP, a measurement of the colour factor ratios CA/CF and TF/CF and the strong coupling constant $\overline{\alpha}_s = CF...

The topology dependence of charged particle multiplicities in three-jet events (1997)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

A study of individual jet and whole-event charged particle multiplicities in three-jet events measured in e+e- annihilation at the Z reveals a significant topology dependence. Mean jet multiplicities...

Studies of quantum chromodynamics with the ALEPH detector (1997)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

Previously published and as yet unpublished QCD results obtained with the ALEPH detector at LEP1 are presented. The unprecedented statistics allows detailed studies of both perturbative and...

Inclusive Production of Neutral Pions in Hadronic Z Decays (1996)

Barate, R, Buskulic, Damir, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

A measurement of the inclusive production of pi0 mesons in hadronic Z decays is presented and compared to Monte Carlo model predictions. The analysis is based on approximately 2 million hadronic...

Measurement of $|V_{cb}|$, form factors and branching fractions in the decays $\overline{B}^0 \to D^{*+}l^- \overline{\nu}_l$ and $\overline{B}^0 \to D^{+}l^{-}\overline{\nu}_l$ (1996)

Buskulic, Damir, De Bonis, I, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

Two samples of exclusive semileptonic decays, 579 B0->D*+l-nu events and 261 B0->D+l-nu events, are selected from approximately 3.9 million hadronic Z decays collected by the ALEPH detector at LEP....

Charm counting in b decays (1996)

Buskulic, Damir, De Bonis, I, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

The inclusive production of charmed particles in Z -> bb decays has been measured from the yield of D^0, D^+, D^+_s and Lambda_{c}^+ decays in a sample of qq events with high b purity collected with...

Improved measurement of the $B^0_d$--$\overline{B}^0_d$ Oscillation frequency (1996)

Buskulic, Damir, De Bonis, I, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

The time dependence of $B^0_d--\bar{B}^0_d$ oscillations is measured by the ALEPH experiment at LEP, using three techniques, two of which are updates of previous measurements. In all cases the charge...

A study of tau decays involving eta and omega mesons (1996)

Buskulic, Damir, De Bonis, I, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

The 132 pb$^{-1}$ of data collected by ALEPH from 1991 to 1994 have been used to analyze $\eta$ and $\omega$ production in $\tau$ decays. The following branching fractions have been measured:...

Observation of charmless hadronic B decays (1996)

Buskulic, Damir, De Bonis, I, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

Four candidates for charmless hadronic B decay are observed in a data sample of four million hadronic Z decays recorded by the {\sc aleph} detector at {\sc lep} . The probability that these events...

Production of orbitally excited charm mesons in semileptonic B decays (1996)

Buskulic, Damir, De Bonis, I, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

Transverse Momentum Correlations in Hadronic Z decays (1996)

Buskulic, Damir, De Bonis, I, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

Using data obtained with the ALEPH detector at the Z resonance, a measure based on transverse momentum is shown to exhibit a correlation between the two halves of a hadronic event which cannot be...

Mass limit for the lightest neutralino (1996)

Buskulic, Damir, De Bonis, I, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

Indirect limits on the mass of the lightest neutralino are derived from the results of searches for charginos, neutralinos, and sleptons performed with data taken by the ALEPH Collaboration at...

Upper limit on the $\nu_{\tau}$ mass from $\tau$ --> 3h$\nu_{\tau}$ decays (1996)

Alexander, Gideon, Allison, J, Altekamp, N, Ametewee, K A, Anderson, K J, Anderson, S, ...

Measurement of hadron and lepton-pair production from e+e- annihilation at centre-of-mass energies of 130 and 136 GeV (1996)

Buskulic, Damir, De Bonis, I, Décamp, D, Ghez, P, Goy, C, Lees, J P, ...

Hadronic and leptonic cross-sections and forward-backward asymmetries are measured using 5.7~pb$^{-1}$ of data taken with the ALEPH detector at LEP at $\cms$ energies of 130 and 136~GeV. The results...

Improved measurement of the lifetime of the $\tau$ lepton (1996)

Alexander, Gideon, Allison, J, Altekamp, N, Ametewee, K A, Anderson, K J, Anderson, S, ...

Topological search for the production of neutralinos and scalar particles (1996)

Alexander, Gideon, Allison, J, Altekamp, N, Ametewee, K A, Anderson, K J, Anderson, S, ...

Measurement of heavy quark forward-backward asymmetries and average B mixing using leptons in multihadronic events (1996)

Alexander, Gideon, Allison, J, Altekamp, N, Ametewee, K A, Anderson, K J, Anderson, S, ...

Search for a Narrow Resonance in $Z^{0}$ Decays into Hadrons and Isolated Photons (1996)

Alexander, Gideon, Allison, J, Altekamp, N, Ametewee, K A, Anderson, K J, Anderson, S, ...

Search for charged Higgs bosons using the OPAL detector at LEP (1995)

Alexander, Gideon, Allison, J, Altekamp, N, Ametewee, K A, Anderson, K J, Anderson, S, ...

Observation of $\Upsilon$ production in hadronic Z$^{0}$ decays (1995)

Alexander, Gideon, Allison, J, Altekamp, N, Ametewee, K A, Anderson, K J, Anderson, S, ...