A. Posthaus

Publication List Details

Period

1994 - 2008

Number

269

Co-Authors

Measurement of the quark to photon fragmentation function through the inclusive production of prompt photons in hadronic Z^0 decays (2008)

Ackerstaff, K, Alexander, G, Allison, J, Altekamp, N, Anderson, K J, Anderson, S, ...

The inclusive production of prompt photons with energy above 10 GeV is measured using the OPAL detector in hadronic Z^0 decays at LEP. In contrast to previous measurements, the prompt photons were...

Measurement of f(c -> D^*+ X), f(b -> D^*+ X) and Gamma_cc(bar)/Gamma_had using D^*+/- Mesons (2008)

Al, K Ackerstaff Et, Ackerstaff, K, Alexander, G, Allison, J, Altekamp, N, Anderson, K J, ...

The production rates of D^*+/- mesons in charm and bottom events at centre-of-mass energies of about 91 GeV and the partial width of primary cc(bar) pairs in hadronic Z^0 decays have been measured at...

A Measurement of the B_s^0 Lifetime using Reconstructed D_s^- Mesons (2008)

Al, K Ackerstaff Et, Ackerstaff, K, Alexander, G, Allison, J, Altekamp, N, Anderson, K J, ...

We report a measurement of the B^0_s meson lifetime from B_s^0 -> D^-_s X decays, where D_s^- mesons are reconstructed in the D_s^- -> phi pi^- and D_s^- -> K^{*0} K^- decay channels. From...

Tests of the Standard Model and Constraints on New Physics from Measurements of Fermion-pair Production at 130-172 GeV at LEP (2008)

Al, K Ackerstaff Et, Alexander, G, Allison, J, Altekamp, N, Anderson, K J, Anderson, S, ...

Production of events with hadronic and leptonic final states has been measured in e^+e^- collisions at centre-of-mass energies of 130-172 GeV, using the OPAL detector at LEP. Cross-sections and...

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...

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...

Search for stable and long-lived massive charged particles in $e^{+} e^{-}$ collisions at $\sqrt{s}$ = 130-183 GeV (1998)

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...

Search for an excess in the production of four-jet events from $e^+ e^-$ collisions at $\sqrt{s}$ = 130-184 GeV (1998)

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...

Determination of the Production Rate of $D^{*0}$ Mesons and of the Ratio V/(V+P) in $Z^{0} \to c\overline{c}$ Decays (1998)

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...

Search for anomalous production of photonic events with missing energy in $e^+ e^-$ collisions at $\sqrt{s}$ = 130-172 GeV (1997)

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...

Search for anomalous production of dilepton events with missing transverse momentum in $e^{+} e^{-}$ collisions at $\sqrt{s}$ = 161 and 172 GeV (1997)

Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, Anderson, S, ...

Events containing a pair of charged leptons and significant missing transverse momentum are selected from a data sample corresponding to a total integrated luminosity of 20.6 pb^-1 at centre-of-mass...

Measurement of triple gauge boson couplings from $W^+ W^-$ production at $\sqrt{s}$ = 172 GeV (1997)

Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, Anderson, S, ...

We present measurements of triple gauge boson coupling parameters using data recorded by the OPAL detector at LEP2 at a centre-of-mass energy of 172 GeV. A total of 120 W-pair candidates has been...

Search for Unstable Heavy and Excited Leptons in $e^+ e^-$ Collisions at $\sqrt{s}$ = 170-172 GeV (1997)

Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, Anderson, S, ...

We have searched for unstable neutral and charged heavy leptons, N and L^+/-, and for excited states of neutral and charged leptons, nu*, e*, mu* and tau*, in e^+e^- collisions at centre-of-mass...

Search for a massive diphoton resonance at $\sqrt{s}$ = 91-172 GeV (1997)

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 total data sample of 25.7 pb^-1 taken at centre-of-mass...

Multi-photon final states in $e^+ e^-$ collisions at $\sqrt{s}$ = 130-172 GeV (1997)

Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, Anderson, S, ...

The process e^+e^- -> gamma gamma (gamma) is studied using data recorded with the OPAL detector at LEP. The data sample corresponds to a total integrated luminosity of 25.38 pb^{-1} taken at...

Search for the Standard Model Higgs Boson in $e^+ e^-$ Collisions at $\sqrt{s}$ = 161-172 GeV (1997)

Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, Anderson, S, ...

This paper describes a search for the Standard Model Higgs boson using data from e^+e^- collisions collected at center-of-mass energies of 161, 170 and 172 GeV by the OPAL detector at LEP. The data...

Multiplicity distributions of gluon and quark jets and tests of QCD analytic predictions (1997)

Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, Anderson, S, ...

Gluon jets are identified in e+e- hadronic annihilation events by tagging two quark jets in the same hemisphere of an event. The gluon jet is defined inclusively as all the particles in the opposite...

Measurement of the photon structure function $F_{2}^{\gamma}$ at low x (1997)

Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, Anderson, S, ...

Deep inelastic electron-photon scattering is studied using e+e- data collected by the OPAL detector at centre-of-mass energies sqrt{s_ee} ~ M_{Z^0}. The photon structure function F_2^gamma(x,Q^2) is...

Polarization and forward-backward asymmetry of $\Lambda$ baryons in hadronic $Z^0$ decays (1997)

Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, Anderson, S, ...

The longitudinal polarization, the transverse polarization, and the forward-backward asymmetry of Lambda baryons have been measured using a sample of 4.34 million hadronic Z^0 decays collected with...

Search for chargino and neutralino production at $\sqrt{s}$ = 170 and 172 GeV at LEP (1997)

Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, Anderson, S, ...

A search for charginos and neutralinos, predicted by supersymmetric theories, has been performed using a data sample of 10.3 pb^-1 at centre-of-mass energies of sqrt(s) = 170 and 172 GeV with the...

Measurement of the branching fractions and forward-backward asymmetries of the $Z^0$ into light quarks (1997)

Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, Anderson, S, ...

Using approximately 4.3 million hadronic Z^0 decays collected with the OPAL detector at LEP between 1990 and 1995, we measure the branching fractions of the Z^0 into up-type and down-type light...

An updated study of B meson oscillations using dilepton events (1997)

Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, Anderson, S, ...

This paper reports a study of B meson oscillations using hadronic Z^0 decays with two identified leptons, and updates a previous publication by including data collected in 1994. Decay times are...

An upper limit on the branching ratio for $\tau$ decays into seven charged particles (1997)

Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, Anderson, S, ...

We have searched for decays of the tau lepton into seven or more charged particles, using data collected with the OPAL detector from 1990 to 1995 in e^+e^- collisions at sqrt(s) ~ M_Z. No candidate...

A study of B meson oscillations using hadronic $Z^0$ decays containing leptons (1997)

Ackerstaff, K, Alexander, Gideon, Allison, J, Altekamp, N, Anderson, K J, Anderson, S, ...

An event sample enriched in semileptonic decays of b hadrons is selected using an inclusive lepton selection from approximately 3.0 million hadronic Z^0 decays collected with the OPAL detector. This...