M. Kasemann

We study CPT-odd non-minimal Lorentz-symmetry violating couplings in the electroweak sector modifying the interactions between leptons, gauge mediators and the Higgs boson. The tree-level (differential) cross sections for three important electroweak processes are discussed: e+e−→ZH, e+e−→ZZ and γγ→W+W−. By considering next-generation e+e− colliders reaching center-of-mass energies at the TeV scale and the estimated improved precision for the measurements of the respective cross sections, we are able to project upper bounds on the purely time-like background 4-vector as strict as ≲10−5GeV−1, in agreement with previous work on similar Lorentz-violating couplings.

The performance of the ALEPH detector at the LEP e+e− collider is reviewed. The accuracy of the tracking detectors to measure the impact parameter and momentum of charged tracks is specified. Calorimeters are used to measure photons and neutral hadrons, and the accuracy obtained in energy and angle is given. An essential property of the detector is its ability to identify particles; the performance in identification of electrons, muons, neutrinos (from missing energy), charged hadrons, π0's and V0's is described.

The double ratio R of the relative decay rates of the short- and long-lived neutral kaons into two charged and two neutral pions was measured to be 0.980±0.004±0.005. The deviation of R from the CP violation in the transition of the CP-odd K2 into two pions with ϵ′/ϵ=(3.3 ± 1.1)×10−3.

The cross-section for e+e− → hadrons in the vicinity of the Z boson peak has been measured with the ALEPH detector at the CERN Large Electron Positron collider, LEP. Measurements of the Z mass, Mz = (91.174±0.070) GeV, the Z width Γz=(2.68±0.15) GeV, and of the peak hadronic cross-section, σhadpeak=(29.3±1.2) nb, are presented. With the constraints of the standard electroweak model, the number of light neutrino species is found to be Nv=3.27±0.30. this results rules out of the possibility of a fourth type of light neutrino at 98% CL.

The performance of the ALEPH Time Projection Chamber (TPC) has been studied using data taken during the LEP running periods in 1989 and 1990. After correction of residual distortions and optimisation of coordinate reconstruction algorithms, single coordinate resolutions of 173 μm in the azimuthal and 740 μm in the longitudinal direction are achieved. This results in a momentum resolution for the TPC of Δp/p2 = 1.2 × 10−3 (GeV/c)−1. In combination with the ALEPH Inner Tracking Chamber (ITC), a total momentum resolution of Δp/p2 = 0.8 × 10−3 (GeV/c)−1 is obtained. With respect to particle identification, the detector achieves a resolution of 4.4% for the measurement of the ionisation energy loss.

The phases of the CP-violating amplitudes in K0→π+π− and K0→2π0 decays, φ+−=46.9°±2.2° and φ00=47.1°±2.8°, have been measured in the same experiment, and a direct comparison gives the phase difference φ00−φ+−=0.2°±2.9°. This result leads to an upper limit on possible CPT violation in the K0 mass matrix, of |(mK0−mK0)/mK0|<5×10−18 at the 95% confidence level and is the most stringent test of the equality of particle and antiparticle masses.

More extensive and precise results are reported on the parameters of Z decay. On the basis of 20 000 Z decays collected with the ALEPH detector at LEP we find Mz=91.182±0.026 (exp.) ±0.030 (beam) GeV, Γz=2.541±0.056 GeV and σhad0=41.4±0.8 nb. The partial widths for the hadronic and leptonic channels are Γhad=1804±44 MeV, Γe+e−=82.1±3.4 MeV, Γμ+μ−=87.9±6.0 MeV and Γτ+τ−=86.1±5.6 MeV, in good agreement with the standard model. On the basis of the average leptonic width Γℓ+ℓ−=83.9±2.2 MeV, the effective weak mixing angle is found to be sin2θw(Mz)=0.231±0.008. Usin g the partial widths calculated in the standard model, the number of light neutrino families is Nν=3.01±0.15 (exp.)±0.05 (theor.).

From an analysis of inclusive leptons in data collected by the ALEPH detector at LEP, we measure the fractions of bb and cc events in hadronic Z decays. The bb fraction times semileptonic branching ratio is measured to be Br(b→e)·Γbb/Γhad= 0.0224 ± 0.0016 ± 0.0010. Assuming a b semileptonic branching ratio of 0.102 ± 0.010 gives Γbb/Γhad= 0.220 ± 0.016 ± 0.024, in good agreement with the standard model prediction of 0.217. The cc fraction times semileptonic branching ratio is measured to be Br(c→e)·Γcc/Γhad= 0.0133 ± 0.0040−0.0031+0.0038. Assuming a c semileptonic branching ratio of 0.090 ± 0.013 gives Γcc/Γhad= 0.148 ± 0.044−0.038+0.045, in agreement with the standard model prediction of 0.171.

The European Particle Physics Strategy Update (EPPSU) process takes a bottom-up approach, whereby the community is first invited to submit proposals (also called inputs) for projects that it would like to see realised in the near-term, mid-term and longer-term future. National inputs as well as inputs from National Laboratories are also an important element of the process. All these inputs are then reviewed by the Physics Preparatory Group (PPG), whose role is to organize a Symposium around the submitted ideas and to prepare a community discussion on the importance and merits of the various proposals. The results of these discussions are then concisely summarised in this Briefing Book, prepared by the Conveners, assisted by Scientific Secretaries, and with further contributions provided by the Contributors listed on the title page. This constitutes the basis for the considerations of the European Strategy Group (ESG), consisting of scientific delegates from CERN Member States, Associate Member States, directors of major European laboratories, representatives of various European organizations as well as invitees from outside the European Community. The ESG has the mission to formulate the European Strategy Update for the consideration and approval of the CERN Council.

A search for the neutral Higgs boson, using the processes Z0→H0e+e−,Z0→H0μ+μ−,Z0→H0τ+τ−,Z0→H0vvandZ0→H0qq, is performed on data collected by the ALEPH detector corresponding to about 11 550 events of Z0 → hadrons. Combining all these processes, the mass range excluded is 32 MeV−15 GeV at 95% CL and 40 MeV−12 GeV at 99% CL. The result from this experiment is unambiguous in the context of the standard model.

We have performed a search for supersymmetric particles using acoplanar pairs of oppositely-charged particles in decays of the Z0. In 0.53 pb−1 of integrated luminosity near the Z0 peak, we observe two events where approximately four are expected from background, allowing limits to be extended on combined photino and slepton masses, and also on combined photino and chargino masses.

A search for Z0 decays into pairs of possible new heavy quarks (t and b′), new heavy charged leptons (L±), stable heavy neutral leptons (νL) and unstable heavy neutral leptons (L0) is performed on data collected by the ALEPH detector corresponding to 11 550 events of Z0→hadrons. The limits on the masses of the heavy quarks are Mt > 45.8 GeV and Mb′ > 46.0 GeV, allowing for both charged-current and flavor-changing neutral-current decays of the b′. If an L± decays into a stable νL, then for MνL<42.7 GeV, the mass of L± is excluded for all values of ML± > MνL. Finally, while the mass of the stable νL is excluded up to 42.7 GeV, the mass of the unstable L0 is excluded up to 45.7 GeV with the mixing parameters |UℓL0|2 down to 10−13 at this mass. For 25.0 GeV < ML0 < 42.7 GeV, all values of |UℓL0|2 are excluded. All limits are given at 95% CL.

The charged particle multiplicity distribution of hadronic Z decays was measured on the peak of the Z resonance using the ALEPH detector at LEP. Using a model independent unfolding procedure the distribution was found to have a mean 〈n〉=20.85±0.24 and a dispersion D=6.34±0.12. Comparison with lower energy data supports the KNO scaling hypothesis in the energy range s=29−91.25 GeV. At s=91.25 GeV the shape of the multiplicity distribution is well described by a log-normal distribution, as predicted from a cascading model for multi-particle production. The same model also successfully describes the energy dependence of the mean and width of the multiplicity distribution. A next-to-leading order QCD prediction in the framework of the modified leading-log approximation and local parton-hadron duality is found to fit the energy dependence of the mean but not the width of the charged multiplicity distribution, indicating that the width of the multiplicity distribution is a sensitive probe for higher order QCD or non-perturbative effects.

A search for the neutral Higgs boson in the mass range above 11 GeV (above the H0→bb threshold), using the process Z0→H0e+e−, Z0→H0μ+μ− and Z0→H0vv, is performed on data collected by the ALEPH detector corresponding to about 25 000 events of Z0→ hadrons. Combining all these processes, the mass range excluded is 11 GeV at 95% CL. Together with a previously published result from ALEPH, the mass range excluded is 32 MeV to 24 GeV at 95% CL. This result also extends the excluded mass region for neutral Higgs bosons from supersymmetry.

A data sample corresponding to about 100 000 hadronic Z decays collected by ALEPH at LEP has been used to search for the standard Higgs boson produced in the reaction e+e− → H0Z0∗. No indication for any signal was found, and a 95% CL lower limit on the Higgs boson mass has been set at 41.6 GeV.

The polarization of τ leptons produced in the reaction e+e−→τ+τ− at the Z resonance has been measured using the τ decay modes eνeντ, μνμντ, πντ, ϱντ, and a1ντ. The mean value obtained is Pτ = −0.152±0.045, indicating that parity is violated in the neutral current process e+e− → τ+τ−. The result corresponds to a ratio of a neutral current vector and axial vector coupling constants of the τ lepton gVτ(M2Z)gAτ(M2Z)= 0.076±0.023 and a value of the electroweak mixing parameter sin2θw(M2Z) = 0.2302 ± 0.0058.

The properties of theZ resonance are measured on the basis of 190 000Z decays into fermion pairs collected with the ALEPH detector at LEP. Assuming lepton universality,M z =(91.182±0.009exp±0.020L∶P) GeV,Г Z =(2484±17) MeV, σ had 0 =(41.44±0.36) nb, andГ jad /Г ℓℓ=21.00±0.20. The corresponding number of light neutrino species is 2.97±0.07. The forward-back-ward asymmetry in leptonic decays is used to determine the ratio of vector to axial-vector coupling constants of leptons:g 2 (M 2 )/g 2 (M 2 )=0.0072±0.0027. Combining these results with ALEPH results on quark charge and $$b\bar b$$ asymmetries, and τ polarization, sin2 θ W (M 2 ). In the contex of the Minimal Standard Model, limits are placed on the top-quark mass.

The light scalar Higgs boson h and the pseudoscalar Higgs boson A of the minimal supersymmetric standard model have been searched for in the processes e+e−→hff and e+e−→hA using data collected by ALEPH at the LEP e+e− collider, with center of mass energies at and near the Z peak. Using a variety of signatures adapted to various mass ranges for h and A, we have excluded a large domain in the parameter space. For large values of ν2ν1, the ratio of the vacuum expectation values of the two Higgs fields, the whole range from 0 to 38.8 GeV is excluded for Mh and MA at 95% CL.

We report on properties of hadronic events from e+e− annihilation observed by the ALEPH detector at the large Electron Positron Collider at CERN. The center-of-mass energy was s=91.0−91.3 GeV. Measured distributions of the global event-shape variables sphericity, aplanarity, thrust and minor value, and of the inclusive variables xp, p⊥in, p⊥out and y are presented. We measure a mean charged multiplicity in hadronic events of 〈Nch〉=21.3±0.1 (statistical)±0.6 (systematic). The data are in good agreement with QCD-based models which use the leading-logarithm approximation, and are less well described by a model using O(αs2) QCD.

The K0 beam and detector used for a high-precision measurement of the CP-violation parameter ϵ′ at the CERN Super Proton Synchrotron (SPS) are described. The beam provides KL and KS alternately through a common decay region. The detection of the decays is based on wire chambers and calorimeters without employing a magnet. The trigger and readout system achieve a high selectively for the suppressed, CP-violating, two-pion decays of the KL by incorporation of hard-wired processors. The readout is based on Fastbus for maximum data rates.

This paper describes a study of Bose-Einstein correlations made using the ALEPH detector at LEP. The correlations are found to enhance the two particle differential cross section for pairs of identical pions by a factor which can be roughly parametrized byR(Q)=1+λ exp(-Q2σ2), whereQ is the difference in the 3-momenta of the two pions in their centre of mass frame, λ=0.51±0.04±0.11 and σ=3.3±0.2±0.8 GeV−1, which corresponds to a source size of 0.65±0.04±0.16 fm. The large systematic errors on these results reflect their strong dependence on the choice of the reference sample used in the analysis. This problem is believed to occur primarily because of uncertainties in the rates of resonance production and a lack of knowledge about the pion-pion strong interaction. No significant correlations are seen amongst like-charged pion-kaon pairs.

We present predictions of the distribution of groomed heavy jet mass in electron-positron collisions at the next-to-next-to-leading order accuracy matched with the resummation of large logarithms to next-to-next-to-next-to-leading logarithmic accuracy. Resummation at this accuracy is possible through extraction of necessary two-loop constants and three-loop anomalous dimensions from fixed-order codes.

An analysis of global event-shape variables has been carried out for the reaction e+e−→Z0→hadrons to measure the strong coupling constant αs. This study is based on 52 720 hadronic events obtained in 1989/90 with the ALEPH detector at the LEP collider at energies near the peak of the Z-resonance. In order to determine αs, second order QCD predictions modified by effects of perturbative higher orders and hadronization were fitted to the experimental distributions of event-shape variables. From a detailed analysis of the theoretical uncertainties we find that this approach is best justified for the differential two-jet rate, from which we obtain αs(MZ2) = 0.121 ± 0.002(stat.)±0.003(sys.)±0.007(theor.) using a renormalization scale ω =12MZ. The dependence of αs(MZ2) on ω is parameterized. For scales mb<ω<MZ the result varies by −0.012+0.007.

Using 106 000 hadronic events obtained with the ALEPH detector at LEP at energies close to the Z resonance peak, the strong coupling constant αs is measured by an analysis of energy-energy correlations (EEC) and the global event shape variables thrust, C-parameter and oblateness. It is shown that the theoretical uncertainties can be significantly reduced if the final state particles are first combined in clusters using a minimum scaled invariant mass cut, Ycut, before these variables are computed. The combined result from all shape variables of pre-clustered events is αs(MZ2 = 0.117±0.005 for a renormalization scale μ=12MZ. For μ values between MZ and the b-quark mass, the result changes by −0.009+0.006.

Limits on Z decay branching ratios into neutralinos are reported. They were obtained from searches for monojets, acoplanar jets, acoplanar lepton pairs, single photons and acoplanar photon pairs as signaturs for the reactions e+e- → χχ′ and e+e- → χχ′, where χ is the lightest neutralino and χ′ any heavier one. The data sample used for these searches corresponds to about 23 000 events of Z decay into multihadrons, collected at LEP by the ALEPH detector for centre of mass energies at and near the Z peak. The results obtained are used to restrict the parameter space of the minimal supersymmetric standard model.

The decay rates of KL → 2γ and KS → 2γ have been measured at the CERN SPS. The results are Γ(KL→2γ)/χ(KL→2π0)=0.632±0.004±0.008 and Γ(KS→2γ)/Γ(KL→2γ)=2.3 ±1.0±0.4. This is the first observation of KS→2γ decays.

In a sample of 190 000 hadronic Z decays, three signals of charm production are observed: two from the exclusive decays D° →K−π+andD∗+→D°π+→K−π+π+ and one in the transverse-momentum distribution of soft hadrons relative to the nearest jet. The features of these signals are in good agreement with expectations based on the standard model and previous measurements of the branching fractions. The number of D∗±→K±π±π± per hadronic decay of the Z is measured to be (5.11±0.34) × 10−3, and the branching ratio B(D0 → K−π+) is (3.62 ± 0.34 ± 0.44)%. Charm hadronization has been studied. The average fraction of the beam energy carried by the D∗ meson is found to be 〈XE〉c = 0.504−0.017+0.013±0.008, and implications of the measurements on the pseudoscalar-to-vector production ratio of charmed mesons are discussed.

A search for pair-produced charged Higgs bosons in decays of the Z0 has been performed using the ALEPH detector at LEP for the decay channels H+H− → ντντ, H+H− → ντ cs and H+H− → cs cs. Searches for two additional decay channels in which cs is replaced by cb were also performed. With 1.17 pb−1 of integrated luminosity, corresponding to about 25 000 hadronic decays of the Z0, the charged Higgs has been excluded at 95% CL in the mass range 7.6 to 43.0 GeV for BR[H± → ντ] = 100%, 8.3 to 40.6 GeV for BR[H±→ντ] = BR[H±→cs] = 50%, and 14.4 to 35.4 GeV for BR[H±→cs] = 100% . With cs replaced by cb, the charged Higgs has been excluded at 95% CL in the mass range 12.0 to 40.7 GeV for BR[H±→ντ] = BR[H±→cb] = 50%, and 16.2 to 35.7 GeV for BR[H±→cb] = 100%.

From a sample of 150 000 hadronic Z decays collected with the ALEPH detector at LEP, events containing prompt leptons are used to measure the forward-backward asymmetries for the channels Z→bb and Z→cc, giving the results AFBb=0.126±0.028±0.012 and AFBc=0.064±0.039±0.030. These asymmetries correspond to the value of effective electroweak mixing angle at the Z mass sin2θW(mZ2) = 0.2262±0.0053.

A search has been made for a very light Higgs boson in the processes e+e- → e+e-H and e+e- →μ+μ-H using data collected by ALEPH at the LEP e+e- collider at centre of mass energies close to the Z peak. The mass range between 0 and 57 MeV is unambigously excluded at the 95% confidence level. If we combine this with our previously published analysis, the complete range from 0 to 24 GeV is excluded at 95% CL. The search is extended to light Higgs bosons of the minimal supersymmetric standard model, with the result that all possibilities of coupling are excluded for Higgs masses below 3 GeV.

A significant charge asymmetry is observed in the hadronic Z decays with the ALEPH detector at LEP. The asymmetry expressed in terms of the difference in momentum weighted charges in the two event hemispheres is measured to be <Qforward>−<Qbackward>= −0.0084±0.0015 (stat.) ±0.0004 (exp. sys.). In the framework of the standard model this can be interpreted as a measurement of the effective electroweak mixing angle, sin2Ow (Mz2=0.2300±0.0034 (stat.) ±0.0010 (exp. sys.) ±0.0038 (theor. sys.) or of the ratio of the vector to axual- vector coupling costants of the electron, gvegAe=+0.073±0.024.

In 160 000 hadronic Z decays recorded with the ALEPH detector at LEP, the yields of Λℓ− and Λℓ+ combinations have been measured. The observed excess of Λℓ− over Λℓ+ of 53±13 is interpreted as evidence for b baryons and their semileptonic decay. Assuming that three body decay processes such as Λb→Λc+ℓ−v dominate the semileptonic decay of b baryons, this ex cess corresponds to a product branching ratio BR(b→Λb)·BR(Λb→Λc+ℓ−v)·BR(Λc+→ΛX) = (0.95±0.22 (stat.)±0.21(syst.))%, where Λb and Λc+ denote the bottom and charm baryons respectively.

Deep inelastic scattering and its diffractive component, $ep \to e^{\prime}\gamma^* p \to e^{\prime}XN$, have been studied at HERA with the ZEUS detector using an integrated luminosity of 52.4 pb$^{-1}$. The $M_X$ method has been used to extract the diffractive contribution. A wide range in the centre-of-mass energy $W$ (37 -- 245 GeV), photon virtuality $Q^2$ (20 -- 450 GeV$^2$) and mass $M_X$ (0.28 -- 35 GeV) is covered. The diffractive cross section for $2 < M_X < 15$ GeV rises strongly with $W$, the rise becoming steeper as $Q^2$ increases. The data are also presented in terms of the diffractive structure function, $F^{\rm D(3)}_2$, of the proton. For fixed $Q^2$ and fixed $M_X$, $\xpom F^{\rm D(3)}_2$ shows a strong rise as $\xpom \to 0$, where $\xpom$ is the fraction of the proton momentum carried by the Pomeron. For Bjorken-$x < 1 \cdot 10^{-3}$, $\xpom F^{\rm D(3)}_2$ shows positive $\log Q^2$ scaling violations, while for $x \ge 5 \cdot 10^{-3}$ negative scaling violations are observed. The diffractive structure function is compatible with being leading twist. The data show that Regge factorisation is broken.

We study electron-positron annihilations into six jets at the parton level in perturbative Quantum Chromo-Dynamics (QCD), via the elementary processes ϵ+ϵ− → qq−gggg, ϵ+ϵ− → qq−q′q−′ gg and ϵ+ϵ− → qq−q′q−′q″q−″, for massive quarks q, q′ and q″ and massless gluons g. Several numerical results of phenomenological relevance are given, at three different collider energies and for a representative selection of jet clustering algorithms. We also present helicity amplitudes and colour factors needed for the tree-level calculation.

We have looked for evidence of excited lepton production in Z0 decay observed in the ALEPH detector at LEP. We find no ℓℓγγ events and set new limits at 95% CL on ℓ∗ masses at 44.6, 44.6 and 41.2 GeV/c2 for e∗, μ∗andτ∗ respectively. Observed events in the ℓℓγ channels are consistent with radiative effects and we set limits for the first time on the ℓ∗ℓZ coupling for ℓ∗ masses in the range up to 86 GeV/c2.

We report on the properties of theZ resonance from 62 500Z decays into fermion pairs collected with the ALEPH detector at LEP, the Large Electron-Positron storage ring at CERN. We findM Z=(91.193±0.016exp±0.030LEP) GeV, Γ Z =(2497±31) MeV, σ had 0 =(41.86±0.66)nb, and for the partial widths Γinv=(489±24) MeV, Γhad(1754±27) MeV, Γ ee =(85.0±1.6)MeV, Γ μμ =(80.0±2.5) MeV, and Γττ=(81.3±2.5) MeV, all in good agreement with the Standard Model. Assuming lepton universality and using a lepton sample without distinction of the final state we measure Γu=(84.3±1.3) MeV. The forward-backward asymmetry in leptonic decays is used to determine the vector and axial-vector weak coupling constants of leptors,g v 2 (M 2 )=(0.12±0.12)×10−2 andg A 2 (M 2 )=0.2528±0.0040. The number of light neutrino species isN ν=2.91±0.13; the electroweak mixing angle is sin2θW(M Z 2 )=0.2291±0.0040.

From more than 175 000 hadronic Z decays observed with the ALEPH detector at LEP, we select 823 events with pairs of leptons in the final state. From these we measure χ, the probability thata b hadron which is observed to decay originated as a b hadron. We find χ=0.132−0.026+0.027.

The production of high energy isolated photons in hadronic Z decays is measured with the ALEPH detector at LEP using a sample of 180 000 hadronic events. Such photons are mainly radiated by quarks, thus giving direct insights into the early parton showering mechanism. The observed rate is compared with a QCD calculation of final state radiation from quarks.

A search for the decay KL→π0e+e− has been performed at the CERN SPS. One candidate event has been found, compatible with an expected background of 1.5 events. The corresponding upper limit for the branching ration is Γ(KL→π0e+e−)Γ(KL → all)<4×10−8 with 90% confidence.

A bstract A search for new top quark interactions is performed within the framework of an effective field theory using the associated production of either one or two top quarks with a Z boson in multilepton final states. The data sample corresponds to an integrated luminosity of 138 fb − 1 of proton-proton collisions at $$ \sqrt{s} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msqrt> <mml:mi>s</mml:mi> </mml:msqrt> </mml:math> = 13 TeV collected by the CMS experiment at the LHC. Five dimension-six operators modifying the electroweak interactions of the top quark are considered. Novel machine-learning techniques are used to enhance the sensitivity to effects arising from these operators. Distributions used for the signal extraction are parameterized in terms of Wilson coefficients describing the interaction strengths of the operators. All five Wilson coefficients are simultaneously fit to data and 95% confidence level intervals are computed. All results are consistent with the SM expectations.

Using the data accumulated at LEP in 1989 and 1990 with the ALEPH detector, the inclusive and exclusive branching ratios of the τ lepton have been measured assuming lepton universality inZ 0 decays. The inclusive branching fractions for the τ decay into one, three, and five charged particles have been determined to be (85.45±0.97)%, (14.35±0.48)%, and (0.10±0.05)%, respectively, in agreement with the world averages. New undetected decay modes are determined to have a branching fraction of less than 2.1% at 95% CL. The measured branching ratios for quasi-exclusive channels are slightly larger than, but consistent with the world averages, except for the modes τ→3 hadrons+v τ andτ→hadron+2π0 v τ , which are significantly larger. These latter branching ratios have been found to be (9.5±0.7)% and (10.2±1.1)%, respectively. The sum of all the measured quasi-exclusive branching ratios is (100.4±1.8)%. A fully exclusive analysis of modes with neutral pions shows no evidence for new photonic decay modes with a branching fraction limit of 3.4% at 95% CL.

Excited neutrinos decaying into a neutrino and a photon are searched for in the ALEPH detector at LEP. No evidence is found for Z decay into v̄v∗ or v̄∗v∗ final states. Upper limits are derived on excited neutrino couplings up to excited neutrino masses close to the Z mass. Lower limits on the v∗ mass, independent of the v∗ decay modes, are deduced from the total Z width.

The results of an investigation based on ALEPH data,e + e − → hadrons at $$\sqrt s = 91$$ GeV, into fluctuations in rapidity space are presented. It is found that the behaviour of the factorial moments is well represented by the Lund parton shower model. An estimate is made of the scale of fluctuations needed to describe the data. Differential moments are introduced and are used to demonstrate that within the average represented by the traditional factorial moments the pattern of fluctuations is itself a strong function of rapidity. This pattern is shown to be primarily associated with the emission of hard gluons. The implied structure between the hadron clusters and partons is explored by the use of transverse mass moments. It is concluded that the principal features of the one-dimensional factorial moments, differential moments and transverse mass moments have their origin in theO(α s ) matrix element, kinematic boundaries and the method of selection of the event axis.

The average lifetime of B hadrons has been measured by the ALEPH experiment at LEP. Events containing B hadrons are selected by the identification of leptons with high transverse momentum in hadronic Z decays, and the lifetime is extracted from a fit to the impact parameter distribution of the lepton tracks. From a sample of 1.7×105 hadronic Z decays a lifetime of 1.29±0.06±0.10 ps is measured.

A Forward Plug Calorimeter (FPC) for the ZEUS detector at HERA has been built as a shashlik lead–scintillator calorimeter with wave length shifter fiber readout. Before installation it was tested and calibrated using the X5 test beam facility of the SPS accelerator at CERN. Electron, muon and pion beams in the momentum range of 10–100 GeV/c were used. Results of these measurements are presented as well as a calibration monitoring system based on a 60Co source.

We report on the absolute luminosity measurement performed with the ALEPH detector at LEP. The systematic errors of the measurements in 1990 are estimated to be 0.6% (experimental) and 0.3% (theoretical).

The CMS experiment expects to manage several Pbytes of data each year during the LHC programme, distributing them over many computing sites around the world and enabling data access at those centers for analysis. CMS has identified the distributed sites as the primary location for physics analysis to support a wide community with thousands potential users. This represents an unprecedented experimental challenge in terms of the scale of distributed computing resources and number of user. An overview of the computing architecture, the software tools and the distributed infrastructure is reported. Summaries of the experience in establishing efficient and scalable operations to get prepared for CMS distributed analysis are presented, followed by the user experience in their current analysis activities.

The mean lifetime of the τ lepton is measured from a sample of Z→τ+τ− decays observed with the ALEPH detector at LEP in 1989 and 1990. A new technique is applied to the events containing two one-prong decays: the lifetime is measured from the observed correlation between the impact parameters and azimuthal angles of the two charged tracks. The lifetime is also determined from measured vertex displacements for three-prong decays and track impact parameters for one-prong decays. The combined results is ττ=291 ± 13 (stat) ±6 (syst.) fs.

We have searched for the sequence of decays KL0→π0H0 and H0→e+e− at the CERN Super Proton Synchrotron (SPS), and have allowed for a non-zero H0 lifetime. Three candidates have been seen, consistent with an expected background of 3.3. Limits on the branching ratio product in the range 10−8–10−7 are presented as a function of the mass and lifetime of the H0. These can be used to restrict the neutral Higgs of the minimal standard model.

In a sample of 200 000 Z decays, events with two leptons and an additional pair of charged particles are studied. The 35 events found show a possible excess in the tau channel compared with the expectation from electroweak processes. The features of the events are consistent with radiation of virtual photons.

The ratios of the numbers of Z bosons decaying to e+e−, μ+μ− and τ+τ− pairs to the number decaying to hadrons have been measured. The branching ratios and partial widths for each channel were determined and found to be equal, consistent with lepton universality. The mean leptonic branching ratio was found to be 0.0321 ± 0.0013 and the leptonic partial width to be 85.4 ± 5.3 MeV. The partial widths for hadronic decays and for invisible decays were deduced to be 1833 ± 116 MeV and 569 ± 92 MeV, respectively. The number of light neutrino types, assuming only the standard model value for the ratio ΘeΘv, was found to be 3.35 ± 0.41.

The present understanding of the factors which limit the rφ measurement accuracy of the ALEPH time projection chamber is outlined. The resolution for high-momentum tracks is shown to be dominated by the E × B and angular affects.

The RadMap Telescope is a new radiation-monitoring instrument operating in the U.S. Orbital Segment of the International Space Station (ISS).The instrument was commissioned in May 2023 and will rotate through four locations inside American, European, and Japanese modules over a period of about six months.In some locations, it will take data alongside operational, validated detectors for a cross-check of measurements.RadMap's central detector is a finely segmented tracking calorimeter that records detailed depth-dose data relevant to studies of the radiation exposure of the ISS crew.It is also able to record particle-dependent energy spectra of cosmic-ray nuclei with energies up to several hundred MeV per nucleon.A unique feature of the detector is its ability to track nuclei with omnidirectional sensitivity at an angular resolution of two degrees.In this contribution, we present the design and capabilities of the RadMap Telescope and give an overview of the instrument's commissioning on the ISS.

A search for events of the type e+e−→ℓ+ℓ−X0, where X0 can be any weakly interacting particle which couples to the Z, has been performed with the ALEPH detector at LEP, by searching for acollinear lepton pairs. Such particles can be excluded up to a mass of 7.0 GeV/c2 for a value of the ratio of branching fractions, Br(Z→X0l+l−)/Br(Z→l+l−), greater than 2.5 × 10−3 if the X0 has third component of isospin, I3 greater than 12 and decays to a pair of virtual gauge bosons. When this analysis is combined with the previous results of the Higgs particle searches from ALEPH, this limit can be extended to an X0 mass of 60 GeV/c2.

The readout system for the Aleph central tracking detector, a large time projection chamber (TPC), consists of more than 100 FASTBUS crates with approximately 1000 FASTBUS modules. The detector and its associated electronics are briefly presented, followed by a more detailed description of the readout and control system. The discussion covers the sector readout, electronics calibration, front-end data acquisition, data pipelining, and service request handling. Experiences with the system are discussed.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Memorial Volume for Jack Steinberger, pp. 161-180 (2022) No AccessImproved measurements of electroweak parameters from Z decays into fermion pairsALEPH Collaboration, D. Decamp, B. Deschizeaux, C. Goy, J.-P. Lees, M.-N. Minard, R. Alemany, J.M. Crespo, M. Delfino, E. Fernandez, V. Gaitan, LI. Garrido, Ll.M. Mir, A. Pacheco, M.G. Catanesi, D. Creanza, M. de Palma, A. Farilla, G. Iaselli, G. Maggi, M. Maggi, S. Natali, S. Nuzzo, M. Quattromini, A. Ranieri, G. Raso, F. Romano, F. Ruggieri, G. Selvaggi, L. Silvestris, P. Tempesta, G. Zito, Y. Gao, H. Hu, D. Huang, X. Huang, J. Lin, J. Lou, C. Qiao, T. Ruan, T. Wang, Y. Xie, D. Xu, R. Xu, J. Zhang, W. Zhao, W.B. Atwood, L.A.T. Bauerdick, F. Bird, E. Blucher, G. Bonvicini, F. Bossi, J. Boudreau, D. Brown, T.H. Burnett, H. Drevermann, R.W. Forty, C. Grab, R. Hagelberg, S. Haywood, J. Hilgart, B. Jost, M. Kasemann, J. Knobloch, A. Lacourt, E. Lançon, I. Lehraus, T. Lohse, A. Lusiani, A. Marchioro, M. Martinez, P. Mato, S. Menary, A. Minten, A. Miotto, R. Miquel, H.-G. Moser, J. Nash, P. Palazzi, F. Ranjard, G. Redlinger, A. Roth, J. Rothberg, H. Rotscheidt, M. Saich, R.St. Denis, D. Schlatter, M. Takashima, M. Talby, W. Tejessy, H. Wachsmuth, S. Wasserbaech, S. Wheeler, W. Wiedenmann, W. Witzeling, J. Wotschack, Z. Ajaltouni, M. Bardadin-Otwinowska, R. El Fellous, A. Falvard, P. Gay, J. Harvey, P. Henrard, J. Jousset, B. Michel, J.-C. Montret, D. Pallin, P. Perret, J. Proriol, F. Prulhière, G. Stimpfl, J.D. Hansen, J.R. Hansen, P.H. Hansen, R. Møllerud, B.S. Nilsson, I. Efthymiopoulos, E. Simopoulou, A. Vayaki, J. Badier, A. Blondel, G. Bonneaud, J. Bourotte, F. Braems, J.C. Brient, G. Fouque, A. Gamess, R. Guirlet, S. Orteu, A. Rosowsky, A. Rougé, M. Rumpf, R. Tanaka, H. Videau, D.J. Candlin, E. Veitch, G. Parrini, M. Corden, C. Georgiopoulos, M. Ikeda, J. Lannutti, D. Levinthal, M. Mermikides, L. Sawyer, A. Antonelli, R. Baldini, G. Bencivenni, G. Bologna, P. Campana, G. Capon, F. Cerutti, V. Chiarella, B. D’Ettorre-Piazzoli, G. Felici, P. Laurelli, G. Mannocchi, F. Murtas, G.P. Murtas, G. Nicoletti, L. Passalacqua, M. Pepe-Altarelli, P. Picchi, P. Zografou, B. Altoon, O. Boyle, A.W. Halley, I. ten Have, J.L. Hearns, J.G. Lynch, W.T. Morton, C. Raine, J.M. Scarr, K. Smith, A.S. Thompson, R.M. Turnbull, B. Brandl, O. Braun, R. Geiges, C. Geweniger, P. Hanke, V. Hepp, E.E. Kluge, Y. Maumary, A. Putzer, B. Rensch, A. Stahl, K. Tittel, M. Wunsch, A.T. Belk, R. Beuselinck, D.M. Binnie, W. Cameron, M. Cattaneo, P.J. Dornan, S. Dugeay, A.M. Greene, J.F. Hassard, N.M. Lieske, S.J. Patton, D.G. Payne, M.J. Phillips, J.K. Sedgbeer, G. Taylor, I.R. Tomalin, A. G. Wright, P. Girtler, D. Kuhn, G. Rudolph, C.K. Bowdery, T.J. Brodbeck, A.J. Finch, F. Foster, G. Hughes, N.R. Keemer, M. Nuttall, A. Patel, B.S. Rowlingson, T. Sloan, S.W. Snow, E.P. Whelan, T. Barczewski, K. Kleinknecht, J. Raab, B. Renk, S. Roehn, H.-G. Sander, M. Schmelling, H. Schmidt, F. Steeg, S.M. Walther, B. Wolf, J-P. Albanese, J-J. Aubert, C. Benchouk, V. Bernard, A. Bonissent, D. Courvoisier, F. Etienne, S. Papalexiou, P. Payre, B. Pietrzyk, Z. Qian, H. Becker, W. Blum, P. Cattaneo, G. Cowan, B. Dehning, H. Dietl, F. Dydak, M. Fernandez-Bosman, T. Hansl-Kozanecka, A. Jahn, W. Kozanecki, E. Lange, J. Lauber, G. Lütjens, G. Lutz, W. Männer, Y. Pan, R. Richter, J. Schröder, A.S. Schwarz, R. Settles, U. Stierlin, J. Thomas, G. Wolf, V. Bertin, J. Boucrot, O. Callot, X. Chen, A. Cordier, M. Davier, G. Ganis, J.-F. Grivaz, Ph. Heusse, P. Janot, D.W. Kim, F. Le Diberder, J. Lefrançois, A.-M. Lutz, J.-J. Veillet, I. Videau, Z. Zhang, F. Zomer, D. Abbaneo, S.R. Amendolia, G. Bagliesi, G. Batignani, L. Bosisio, U. Bottigli, C. Bradaschia, M. Carpinelli, M.A. Ciocci, R. Dell’Orso, I. Ferrante, F. Fidecaro, L. Foà, E. Focardi, F. Forti, C. Gatto, A. Giassi, M.A. Giorgi, F. Ligabue, E.B. Mannelli, P.S. Marrocchesi, A. Messineo, L. Moneta, F. Palla, G. Sanguinetti, J. Steinberger, R. Tenchini, G. Tonelli, G. Triggiani, C. Vannini, A. Venturi, P.G. Verdini, J. Walsh, J.M. Carter, M.G. Green, P.V. March, T. Medcalf, I.S. Quazi, J.A. Strong, R.M. Thomas, L.R. West, T. Wildish, D.R. Botterill, R.W. Clifft, T.R. Edgecock, M. Edwards, S.M. Fisher, T.J. Jones, P.R. Norton, D.P. Salmon, J.C. Thompson, B. Bloch-Devaux, P. Colas, C. Klopfenstein, E. Locci, S. Loucatos, E. Monnier, P. Perez, J.A. Perlas, F. Perrier, J. Rander, J.-F. Renardy, A. Roussarie, J.-P. Schuller, J. Schwindling, B. Vallage, J.G. Ashman, C.N. Booth, C. Buttar, R. Carney, S. Cartwright, F. Combley, M. Dinsdale, M. Dogru, F. Hatfield, J. Martin, D. Parker, P. Reeves, L.F. Thompson, E. Barberio, S. Brandt, H. Burkhardt, C. Grupen, H. Meinhard, L. Mirabito, U. Schäfer, H. Seywerd, G. Apollinari, G. Giannini, B. Gobbo, F. Liello, F. Ragusa, L. Rolandi, U. Stiegler, L. Bellantoni, X. Chen, D. Cinabro, J.S. Conway, D.F. Cowen, Z. Feng, D.P.S. Ferguson, Y.S. Gao, J. Grahl, J.L. Harton, J.E. Jacobsen, R.C. Jared, R.P. Johnson, B.W. Le Claire, Y.B. Pan, J.R. Pater, Y. Saadi, V. Sharma, Z.H. Shi, Y.H. Tang, A.M. Walsh, J.A. Wear, F.V. Weber, M.H. Whitney, Sau Lan Wu and G. ZobernigALEPH Collaboration, D. DecampLaboratoire de Physique des Particules (LAPP), IN2P3-CNRS, F-74019 Annecy-le-Vieux Cedex, France, B. DeschizeauxLaboratoire de Physique des Particules (LAPP), IN2P3-CNRS, F-74019 Annecy-le-Vieux Cedex, France, C. GoyLaboratoire de Physique des Particules (LAPP), IN2P3-CNRS, F-74019 Annecy-le-Vieux Cedex, France, J.-P. LeesLaboratoire de Physique des Particules (LAPP), IN2P3-CNRS, F-74019 Annecy-le-Vieux Cedex, France, M.-N. MinardLaboratoire de Physique des Particules (LAPP), IN2P3-CNRS, F-74019 Annecy-le-Vieux Cedex, France, R. AlemanyLaboratorio de Fisica de Altas Energías, Universidad Autonoma de Barcelona, E-08193 Bellaterra (Barcelona), Spain, J.M. CrespoLaboratorio de Fisica de Altas Energías, Universidad Autonoma de Barcelona, E-08193 Bellaterra (Barcelona), Spain, M. DelfinoLaboratorio de Fisica de Altas Energías, Universidad Autonoma de Barcelona, E-08193 Bellaterra (Barcelona), Spain, E. FernandezLaboratorio de Fisica de Altas Energías, Universidad Autonoma de Barcelona, E-08193 Bellaterra (Barcelona), Spain, V. GaitanLaboratorio de Fisica de Altas Energías, Universidad Autonoma de Barcelona, E-08193 Bellaterra (Barcelona), Spain, LI. GarridoLaboratorio de Fisica de Altas Energías, Universidad Autonoma de Barcelona, E-08193 Bellaterra (Barcelona), Spain, Ll.M. MirLaboratorio de Fisica de Altas Energías, Universidad Autonoma de Barcelona, E-08193 Bellaterra (Barcelona), Spain, A. PachecoLaboratorio de Fisica de Altas Energías, Universidad Autonoma de Barcelona, E-08193 Bellaterra (Barcelona), Spain, M.G. CatanesiINFN Sezione di Bari e Dipartimento di Fisica dell’ Università, 1-70126 Bari, Italy, D. CreanzaINFN Sezione di Bari e Dipartimento di Fisica dell’ Università, 1-70126 Bari, Italy, M. de PalmaINFN Sezione di Bari e Dipartimento di Fisica dell’ Università, 1-70126 Bari, Italy, A. FarillaINFN Sezione di Bari e Dipartimento di Fisica dell’ Università, 1-70126 Bari, Italy, G. IaselliINFN Sezione di Bari e Dipartimento di Fisica dell’ Università, 1-70126 Bari, Italy, G. MaggiINFN Sezione di Bari e Dipartimento di Fisica dell’ Università, 1-70126 Bari, Italy, M. MaggiINFN Sezione di Bari e Dipartimento di Fisica dell’ Università, 1-70126 Bari, Italy, S. NataliINFN Sezione di Bari e Dipartimento di Fisica dell’ Università, 1-70126 Bari, Italy, S. NuzzoINFN Sezione di Bari e Dipartimento di Fisica dell’ Università, 1-70126 Bari, Italy, M. QuattrominiINFN Sezione di Bari e Dipartimento di Fisica dell’ Università, 1-70126 Bari, Italy, A. RanieriINFN Sezione di Bari e Dipartimento di Fisica dell’ Università, 1-70126 Bari, Italy, G. RasoINFN Sezione di Bari e Dipartimento di Fisica dell’ Università, 1-70126 Bari, Italy, F. RomanoINFN Sezione di Bari e Dipartimento di Fisica dell’ Università, 1-70126 Bari, Italy, F. RuggieriINFN Sezione di Bari e Dipartimento di Fisica dell’ Università, 1-70126 Bari, Italy, G. SelvaggiINFN Sezione di Bari e Dipartimento di Fisica dell’ Università, 1-70126 Bari, Italy, L. SilvestrisINFN Sezione di Bari e Dipartimento di Fisica dell’ Università, 1-70126 Bari, Italy, P. TempestaINFN Sezione di Bari e Dipartimento di Fisica dell’ Università, 1-70126 Bari, Italy, G. ZitoINFN Sezione di Bari e Dipartimento di Fisica dell’ Università, 1-70126 Bari, Italy, Y. GaoInstitute of High-Energy Physics, Academia Sinica. Beijing, People’s Republic of China, H. HuInstitute of High-Energy Physics, Academia Sinica. Beijing, People’s Republic of China, D. HuangInstitute of High-Energy Physics, Academia Sinica. Beijing, People’s Republic of China, X. HuangInstitute of High-Energy Physics, Academia Sinica. Beijing, People’s Republic of China, J. LinInstitute of High-Energy Physics, Academia Sinica. Beijing, People’s Republic of China, J. LouInstitute of High-Energy Physics, Academia Sinica. Beijing, People’s Republic of China, C. QiaoInstitute of High-Energy Physics, Academia Sinica. Beijing, People’s Republic of China, T. RuanInstitute of High-Energy Physics, Academia Sinica. Beijing, People’s Republic of China, T. WangInstitute of High-Energy Physics, Academia Sinica. Beijing, People’s Republic of China, Y. XieInstitute of High-Energy Physics, Academia Sinica. Beijing, People’s Republic of China, D. XuInstitute of High-Energy Physics, Academia Sinica. Beijing, People’s Republic of China, R. XuInstitute of High-Energy Physics, Academia Sinica. Beijing, People’s Republic of China, J. ZhangInstitute of High-Energy Physics, Academia Sinica. Beijing, People’s Republic of China, W. ZhaoInstitute of High-Energy Physics, Academia Sinica. Beijing, People’s Republic of China, W.B. AtwoodEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, L.A.T. BauerdickEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, F. BirdEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, E. BlucherEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, G. BonviciniEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, F. BossiEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, J. BoudreauEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, D. BrownEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, T.H. BurnettEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, H. DrevermannEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, R.W. FortyEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, C. GrabEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, R. HagelbergEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, S. HaywoodEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, J. HilgartEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, B. JostEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, M. KasemannEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, J. KnoblochEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, A. LacourtEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, E. LançonEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, I. LehrausEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, T. LohseEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, A. LusianiEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, A. MarchioroEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, M. MartinezEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, P. MatoEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, S. MenaryEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, A. MintenEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, A. MiottoEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, R. MiquelEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, H.-G. MoserEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, J. NashEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, P. PalazziEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, F. RanjardEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, G. RedlingerEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, A. RothEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, J. RothbergEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, H. RotscheidtEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, M. SaichEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, R.St. DenisEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, D. SchlatterEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, M. TakashimaEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, M. TalbyEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, W. TejessyEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, H. WachsmuthEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, S. WasserbaechEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, S. WheelerEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, W. WiedenmannEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, W. WitzelingEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, J. WotschackEuropean Laboratory for Particle Physics (CERN), CH-1211 Geneva 23, Switzerland, Z. AjaltouniLaboratoire de Physique Corpusculaire, Université Blaise Pascal, IN2P3-CNRS, Clermont-Ferrand, F-63177 Aubière, France, M. Bardadin-OtwinowskaLaboratoire de Physique Corpusculaire, Université Blaise Pascal, IN2P3-CNRS, Clermont-Ferrand, F-63177 Aubière, France, R. El FellousLaboratoire de Physique Corpusculaire, Université Blaise Pascal, IN2P3-CNRS, Clermont-Ferrand, F-63177 Aubière, France, A. FalvardLaboratoire de Physique Corpusculaire, Université Blaise Pascal, IN2P3-CNRS, Clermont-Ferrand, F-63177 Aubière, France, P. GayLaboratoire de Physique Corpusculaire, Université Blaise Pascal, IN2P3-CNRS, Clermont-Ferrand, F-63177 Aubière, France, J. HarveyLaboratoire de Physique Corpusculaire, Université Blaise Pascal, IN2P3-CNRS, Clermont-Ferrand, F-63177 Aubière, France, P. HenrardLaboratoire de Physique Corpusculaire, Université Blaise Pascal, IN2P3-CNRS, Clermont-Ferrand, F-63177 Aubière, France, J. JoussetLaboratoire de Physique Corpusculaire, Université Blaise Pascal, IN2P3-CNRS, Clermont-Ferrand, F-63177 Aubière, France, B. MichelLaboratoire de Physique Corpusculaire, Université Blaise Pascal, IN2P3-CNRS, Clermont-Ferrand, F-63177 Aubière, France, J.-C. MontretLaboratoire de Physique Corpusculaire, Université Blaise Pascal, IN2P3-CNRS, Clermont-Ferrand, F-63177 Aubière, France, D. PallinLaboratoire de Physique Corpusculaire, Université Blaise Pascal, IN2P3-CNRS, Clermont-Ferrand, F-63177 Aubière, France, P. PerretLaboratoire de Physique Corpusculaire, Université Blaise Pascal, IN2P3-CNRS, Clermont-Ferrand, F-63177 Aubière, France, J. ProriolLaboratoire de Physique Corpusculaire, Université Blaise Pascal, IN2P3-CNRS, Clermont-Ferrand, F-63177 Aubière, France, F. PrulhièreLaboratoire de Physique Corpusculaire, Université Blaise Pascal, IN2P3-CNRS, Clermont-Ferrand, F-63177 Aubière, France, G. StimpflLaboratoire de Physique Corpusculaire, Université Blaise Pascal, IN2P3-CNRS, Clermont-Ferrand, F-63177 Aubière, France, J.D. HansenNiels Bohr Institute, DK-2100 Copenhagen, Denmark, J.R. HansenNiels Bohr Institute, DK-2100 Copenhagen, Denmark, P.H. HansenNiels Bohr Institute, DK-2100 Copenhagen, Denmark, R. MøllerudNiels Bohr Institute, DK-2100 Copenhagen, Denmark, B.S. NilssonNiels Bohr Institute, DK-2100 Copenhagen, Denmark, I. EfthymiopoulosNuclear Research Center Demokritos (NRCD), Athens, Greece, E. SimopoulouNuclear Research Center Demokritos (NRCD), Athens, Greece, A. VayakiNuclear Research Center Demokritos (NRCD), Athens, Greece, J. BadierLaboratoire de Physique Nucléaire et des Hautes Energies, Ecole Polytechnique, IN2P3-CNRS, F-91128 Palaiseau Cedex, France, A. BlondelLaboratoire de Physique Nucléaire et des Hautes Energies, Ecole Polytechnique, IN2P3-CNRS, F-91128 Palaiseau Cedex, France, G. BonneaudLaboratoire de Physique Nucléaire et des Hautes Energies, Ecole Polytechnique, IN2P3-CNRS, F-91128 Palaiseau Cedex, France, J. BourotteLaboratoire de Physique Nucléaire et des Hautes Energies, Ecole Polytechnique, IN2P3-CNRS, F-91128 Palaiseau Cedex, France, F. BraemsLaboratoire de Physique Nucléaire et des Hautes Energies, Ecole Polytechnique, IN2P3-CNRS, F-91128 Palaiseau Cedex, France, J.C. BrientLaboratoire de Physique Nucléaire et des Hautes Energies, Ecole Polytechnique, IN2P3-CNRS, F-91128 Palaiseau Cedex, France, G. FouqueLaboratoire de Physique Nucléaire et des Hautes Energies, Ecole Polytechnique, IN2P3-CNRS, F-91128 Palaiseau Cedex, France, A. GamessLaboratoire de Physique Nucléaire et des Hautes Energies, Ecole Polytechnique, IN2P3-CNRS, F-91128 Palaiseau Cedex, France, R. GuirletLaboratoire de Physique Nucléaire et des Hautes Energies, Ecole Polytechnique, IN2P3-CNRS, F-91128 Palaiseau Cedex, France, S. OrteuLaboratoire de Physique Nucléaire et des Hautes Energies, Ecole Polytechnique, IN2P3-CNRS, F-91128 Palaiseau Cedex, France, A. RosowskyLaboratoire de Physique Nucléaire et des Hautes Energies, Ecole Polytechnique, IN2P3-CNRS, F-91128 Palaiseau Cedex, France, A. RougéLaboratoire de Physique Nucléaire et des Hautes Energies, Ecole Polytechnique, IN2P3-CNRS, F-91128 Palaiseau Cedex, France, M. RumpfLaboratoire de Physique Nucléaire et des Hautes Energies, Ecole Polytechnique, IN2P3-CNRS, F-91128 Palaiseau Cedex, France, R. TanakaLaboratoire de Physique Nucléaire et des Hautes Energies, Ecole Polytechnique, IN2P3-CNRS, F-91128 Palaiseau Cedex, France, H. VideauLaboratoire de Physique Nucléaire et des Hautes Energies, Ecole Polytechnique, IN2P3-CNRS, F-91128 Palaiseau Cedex, France, D.J. CandlinDepartment of Physics, University of Edinburgh, Edinburgh EH93JZ, UK, E. VeitchDepartment of Physics, University of Edinburgh, Edinburgh EH93JZ, UK, G. ParriniDipartimento di Fisica, Università di Firenze, INFN Sezione di Firenze, 1-50125 Firenze, Italy, M. CordenSupercomputer Computations Research Institute and Department of Physics, Florida State University, Tallahassee, FL 32306, USA, C. GeorgiopoulosSupercomputer Computations Research Institute and Department of Physics, Florida State University, Tallahassee, FL 32306, USA, M. IkedaSupercomputer Computations Research Institute and Department of Physics, Florida State University, Tallahassee, FL 32306, USA, J. LannuttiSupercomputer Computations Research Institute and Department of Physics, Florida State University, Tallahassee, FL 32306, USA, D. LevinthalSupercomputer Computations Research Institute and Department of Physics, Florida State University, Tallahassee, FL 32306, USA, M. MermikidesSupercomputer Computations Research Institute and Department of Physics, Florida State University, Tallahassee, FL 32306, USA, L. SawyerSupercomputer Computations Research Institute and Department of Physics, Florida State University, Tallahassee, FL 32306, USA, A. AntonelliLaboratori Nazionali dell’INFN (LNF-INFN), 1-00044 Frascati, Italy, R. BaldiniLaboratori Nazionali dell’INFN (LNF-INFN), 1-00044 Frascati, Italy, G. BencivenniLaboratori Nazionali dell’INFN (LNF-INFN), 1-00044 Frascati, Italy, G. BolognaLaboratori Nazionali dell’INFN (LNF-INFN), 1-00044 Frascati, Italy, P. CampanaLaboratori Nazionali dell’INFN (LNF-INFN), 1-00044 Frascati, Italy, G. CaponLaboratori Nazionali dell’INFN (LNF-INFN), 1-00044 Frascati, Italy, F. CeruttiLaboratori Nazionali dell’INFN (LNF-INFN), 1-00044 Frascati, Italy, V. ChiarellaLaboratori Nazionali dell’INFN (LNF-INFN), 1-00044 Frascati, Italy, B. D’Ettorre-PiazzoliLaboratori Nazionali dell’INFN (LNF-INFN), 1-00044 Frascati, Italy, G. FeliciLaboratori Nazionali dell’INFN (LNF-INFN), 1-00044 Frascati, Italy, P. LaurelliLaboratori Nazionali dell’INFN (LNF-INFN), 1-00044 Frascati, Italy, G. MannocchiLaboratori Nazionali dell’INFN (LNF-INFN), 1-00044 Frascati, Italy, F. MurtasLaboratori Nazionali dell’INFN (LNF-INFN), 1-00044 Frascati, Italy, G.P. MurtasLaboratori Nazionali dell’INFN (LNF-INFN), 1-00044 Frascati, Italy, G. NicolettiLaboratori Nazionali dell’INFN (LNF-INFN), 1-00044 Frascati, Italy, L. PassalacquaLaboratori Nazionali dell’INFN (LNF-INFN), 1-00044 Frascati, Italy, M. Pepe-AltarelliLaboratori Nazionali dell’INFN (LNF-INFN), 1-00044 Frascati, Italy, P. PicchiLaboratori Nazionali dell’INFN (LNF-INFN), 1-00044 Frascati, Italy, P. ZografouLaboratori Nazionali dell’INFN (LNF-INFN), 1-00044 Frascati, Italy, B. AltoonDepartment of Physics and Astronomy, University of Glasgow, Glasgow G128QQ, UK, O. BoyleDepartment of Physics and Astronomy, University of Glasgow, Glasgow G128QQ, UK, A.W. HalleyDepartment of Physics and Astronomy, University of Glasgow, Glasgow G128QQ, UK, I. ten HaveDepartment of Physics and Astronomy, University of Glasgow, Glasgow G128QQ, UK, J.L. HearnsDepartment of Physics and Astronomy, University of Glasgow, Glasgow G128QQ, UK, J.G. LynchDepartment of Physics and Astronomy, University of Glasgow, Glasgow G128QQ, UK, W.T. MortonDepartment of Physics and Astronomy, University of Glasgow, Glasgow G128QQ, UK, C. RaineDepartment of Physics and Astronomy, University of Glasgow, Glasgow G128QQ, UK, J.M. ScarrDepartment of Physics and Astronomy, University of Glasgow, Glasgow G128QQ, UK, K. SmithDepartment of Physics and Astronomy, University of Glasgow, Glasgow G128QQ, UK, A.S. ThompsonDepartment of Physics and Astronomy, University of Glasgow, Glasgow G128QQ, UK, R.M. TurnbullDepartment of Physics and Astronomy, University of Glasgow, Glasgow G128QQ, UK, B. BrandlInstitut für Hochenergiephysik, Universität Heidelberg, W-6900 Heidelberg, Federal Republic of Germany, O. BraunInstitut für Hochenergiephysik, Universität Heidelberg, W-6900 Heidelberg, Federal Republic of Germany, R. GeigesInstitut für Hochenergiephysik, Universität Heidelberg, W-6900 Heidelberg, Federal Republic of Germany, C. GewenigerInstitut für Hochenergiephysik, Universität Heidelberg, W-6900 Heidelberg, Federal Republic of Germany, P. HankeInstitut für Hochenergiephysik, Universität Heidelberg, W-6900 Heidelberg, Federal Republic of Germany, V. HeppInstitut für Hochenergiephysik, Universität Heidelberg, W-6900 Heidelberg, Federal Republic of Germany, E.E. KlugeInstitut für Hochenergiephysik, Universität Heidelberg, W-6900 Heidelberg, Federal Republic of Germany, Y. MaumaryInstitut für Hochenergiephysik, Universität Heidelberg, W-6900 Heidelberg, Federal Republic of Germany, A. PutzerInstitut für Hochenergiephysik, Universität Heidelberg, W-6900 Heidelberg, Federal Republic of Germany, B. RenschInstitut für Hochenergiephysik, Universität Heidelberg, W-6900 Heidelberg, Federal Republic of Germany, A. StahlInstitut für Hochenergiephysik, Universität Heidelberg, W-6900 Heidelberg, Federal Republic of Germany, K. TittelInstitut für Hochenergiephysik, Universität Heidelberg, W-6900 Heidelberg, Federal Republic of Germany, M. WunschInstitut für Hochenergiephysik, Universität Heidelberg, W-6900 Heidelberg, Federal Republic of Germany, A.T. BelkDepartment of Physics, Imperial College, London SW72BZ, UK, R. BeuselinckDepartment of Physics, Imperial College, London SW72BZ, UK, D.M. BinnieDepartment of Physics, Imperial College, London SW72BZ, UK, W. CameronDepartment of Physics, Imperial College, London SW72BZ, UK, M. CattaneoDepartment of Physics, Imperial College, London SW72BZ, UK, P.J. DornanDepartment of Physics, Imperial College, London SW72BZ, UK, S. DugeayDepartment of Physics, Imperial College, London SW72BZ, UK, A.M. GreeneDepartment of Physics, Imperial College, London SW72BZ, UK, J.F. HassardDepartment of Physics, Imperial College, London SW72BZ, UK, N.M. LieskeDepartment of Physics, Imperial College, London SW72BZ, UK, S.J. PattonDepartment of Physics, Imperial College, London SW72BZ, UK, D.G. PayneDepartment of Physics, Imperial College, London SW72BZ, UK, M.J. PhillipsDepartment of Physics, Imperial College, London SW72BZ, UK, J.K. SedgbeerDepartment of Physics, Imperial College, London SW72BZ, UK, G. TaylorDepartment of Physics, Imperial College, London SW72BZ, UK, I.R. TomalinDepartment of Physics, Imperial College, London SW72BZ, UK, A. G. WrightDepartment of Physics, Imperial College, London SW72BZ, UK, P. GirtlerInstitut für Experimentalphysik, Universität Innsbruck, A-6020 Innbruck, Austria, D. KuhnInstitut für Experimentalphysik, Universität Innsbruck, A-6020 Innbruck, Austria, G. RudolphInstitut für Experimentalphysik, Universität Innsbruck, A-6020 Innbruck, Austria, C.K. BowderyDepartment of Physics, University of Lancaster, Lancaster LA14YB, UK, T.J. BrodbeckDepartment of Physics, University of Lancaster, Lancaster LA14YB, UK, A.J. FinchDepartment of Physics, University of Lancaster, Lancaster LA14YB, UK, F. FosterDepartment of Physics, University of Lancaster, Lancaster LA14YB, UK, G. HughesDepartment of Physics, University of Lancaster, Lancaster LA14YB, UK, N.R. KeemerDepartment of Physics, University of Lancaster, Lancaster LA14YB, UK, M. NuttallDepartment of Physics, University of Lancaster, Lancaster LA14YB, UK, A. PatelDepartment of Physics, University of Lancaster, Lancaster LA14YB, UK, B.S. RowlingsonDepartment of Physics, University of Lancaster, Lancaster LA14YB, UK, T. SloanDepartment of Physics, University of Lancaster, Lancaster LA14YB, UK, S.W. SnowDepartment of Physics, University of Lancaster, Lancaster LA14YB, UK, E.P. WhelanDepartment of Physics, University of Lancaster, Lancaster LA14YB, UK, T. BarczewskiInstitut für Physik, Universität Mainz, W-6500 Mainz, Federal Republic of Germany, K. KleinknechtInstitut für Physik, Universität Mainz, W-6500 Mainz, Federal Republic of Germany, J. RaabInstitut für Physik, Universität Mainz, W-6500 Mainz, Federal Republic of Germany, B. RenkInstitut für Physik, Universität Mainz, W-6500 Mainz, Federal Republic of Germany, S. RoehnInstitut für Physik, Universität Mainz, W-6500 Mainz, Federal Republic of Germany, H.-G. SanderInstitut für Physik, Universität Mainz, W-6500 Mainz, Federal Republic of Germany, M. SchmellingInstitut für Physik, Universität Mainz, W-6500 Mainz, Federal Republic of Germany, H. SchmidtInstitut für Physik, Universität Mainz, W-6500 Mainz, Federal Republic of Germany, F. SteegInstitut für Physik, Universität Mainz, W-6500 Mainz, Federal Republic of Germany, S.M. WaltherInstitut für Physik, Universität Mainz, W-6500 Mainz, Federal Republic of Germany, B. WolfInstitut für Physik, Universität Mainz, W-6500 Mainz, Federal Republic of Germany, J-P. AlbaneseCentre de Physique des Particules, Faculté des Sciences de Luminy, IN2P3-CNRS, F-13288 Marseille, France, J-J. AubertCentre de Physique des Particules, Faculté des Sciences de Luminy, IN2P3-CNRS, F-13288 Marseille, France, C. BenchoukCentre de Physique des Particules, Faculté des Sciences de Luminy, IN2P3-CNRS, F-13288 Marseille, France, V. BernardCentre de Physique des Particules, Faculté des Sciences de Luminy, IN2P3-CNRS, F-13288 Marseille, France, A. BonissentCentre de Physique des Particules, Faculté des Sciences de Luminy, IN2P3-CNRS, F-13288 Marseille, France, D. CourvoisierCentre de Physique des Particules, Faculté des Sciences de Luminy, IN2P3-CNRS, F-13288 Marseille, France, F. EtienneCentre de Physique des Particules, Faculté des Sciences de Luminy, IN2P3-CNRS, F-13288 Marseille, France, S. PapalexiouCentre de Physique des Particules, Faculté des Sciences de Luminy, IN2P3-CNRS, F-13288 Marseille, France, P. PayreCentre de Physique des Particules, Faculté des Sciences de Luminy, IN2P3-CNRS, F-13288 Marseille, France, B. PietrzykCentre de Physique des Particules, Faculté des Sciences de Luminy, IN2P3-CNRS, F-13288 Marseille, France, Z. QianCentre de Physique des Particules, Faculté des Sciences de Luminy, IN2P3-CNRS, F-13288 Marseille, France, H. BeckerMax-Planck-Institut für Physik und Astrophysik, Werner-Heisenberg-Institut für Physik, W-8000 München, Federal Republic of Germany, W. BlumMax-Planck-Institut für Physik und Astrophysik, Werner-Heisenberg-Institut für Physik, W-8000 München, Federal Republic of Germany, P. CattaneoMax-Planck-Institut für Physik und Astrophysik, Werner-Heisenberg-Institut für Physik, W-8000 München, Federal Republic of Germany, G. CowanMax-Planck-Institut für Physik und Astrophysik, Werner-Heisenberg-Institut für Physik, W-8000 München, Federal Republic of Germany, B. DehningMax-Planck-Institut für Physik und Astrophysik, Werner-Heisenberg-Institut für Physik, W-8000 München, Federal Republic of Germany, H. DietlMax-Planck-Institut für Physik und Astrophysik, Werner-Heisenberg-Institut für Physik, W-8000 München, Federal Republic of Germany, F. DydakMax-Planck-Institut für Physik und Astrophysik, Werner-Heisenberg-Institut für Physik, W-8000 München, Federal Republic of Germany, M. Fernandez-BosmanMax-Planck-Institut für Physik und Astrophysik, Werner-Heisenberg-Institut für Physik, W-8000 München, Federal Republic of Germany, T. Hansl-KozaneckaMax-Planck-Institut für Physik und Astrophysik, Werner-Heisenberg-Institut für Physik, W-8000 München, Federal Republic of Germany, A. JahnMax-Planck-Institut für Physik und Astrophysik, Werner-Heisenberg-Institut für Physik, W-8000 München, Federal Republic of Germany, W. KozaneckiMax-Planck-Institut für Physik und Astrophysik, Werner-Heisenberg-Institut für Physik, W-8000 München, Federal Republic of Germany, E. LangeMax-Planck-Institut für Physik und Astrophysik, Werner-Heisenberg-Institut für Physik, W-8000 München, Federal Republic of Germany, J. LauberMax-Planck-Institut für Physik und Astrophysik, Werner-Heisenberg-Institut für Physik, W-8000 München, Federal Republic of Germany, G. LütjensMax-Planck-Institut für Physik und Astrophysik, Werner-Heisenberg-Institut für Physik, W-8000 München, Federal Republic of Germany, G. LutzMax-Planck-Institut für Physik und Astrophysik, Werner-Heisenberg-Institut für Physik, W-8000 München, Federal Republic of Germany, W. MännerMax-Planck-Institut für Physik und Astrophysik, Werner-Heisenberg-Institut für Physik, W-8000 München, Federal Republic of Germany, Y. PanMax-Planck-Institut für Physik und Astrophysik, Werner-Heisenberg-Institut für Physik, W-8000 München, Federal Republic of Germany, R. RichterMax-Planck-Institut für Physik und Astrophysik, Werner-Heisenberg-Institut für Physik, W-8000 München, Federal Republic of Germany, J. SchröderMax-Planck-Institut für Physik und Astrophysik, Werner-Heisenberg-Institut für Physik, W-8000 München, Federal Republic of Germany, A.S. SchwarzMax-Planck-Institut für Physik und Astrophysik, Werner-Heisenberg-Institut für Physik, W-8000 München, Federal Republic of Germany, R. SettlesMax-Planck-Institut für Physik und Astrophysik, Werner-Heisenberg-Institut für Physik, W-8000 München, Federal Republic of Germany, U. StierlinMax-Planck-Institut für Physik und Astrophysik, Werner-Heisenberg-Institut für Physik, W-8000 München, Federal Republic of Germany, J. ThomasMax-Planck-Institut für Physik und Astrophysik, Werner-Heisenberg-Institut für Physik, W-8000 München, Federal Republic of Germany, G. WolfMax-Planck-Institut für Physik und Astrophysik, Werner-Heisenberg-Institut für Physik, W-8000 München, Federal Republic of Germany, V. BertinLaboratoire de l’Accélérateur Linéaire, Université de Paris-Sud, INP-CNRS, F-91405 Orsay Cedex, France, J. BoucrotLaboratoire de l’Accélérateur Linéaire, Université de Paris-Sud, INP-CNRS, F-91405 Orsay Cedex, France, O. CallotLaboratoire de l’Accélérateur Linéaire, Université de Paris-Sud, INP-CNRS, F-91405 Orsay Cedex, France, X. ChenLaboratoire de l’Accélérateur Linéaire, Université de Paris-Sud, INP-CNRS, F-91405 Orsay Cedex, France, A. CordierLaboratoire de l’Accélérateur Linéaire, Université de Paris-Sud, INP-CNRS, F-91405 Orsay Cedex, France, M. DavierLaboratoire de l’Accélérateur Linéaire, Université de Paris-Sud, INP-CNRS, F-91405 Orsay Cedex, France, G. GanisLaboratoire de l’Accélérateur Linéaire, Université de Paris-Sud, INP-CNRS, F-91405 Orsay Cedex, France, J.-F. GrivazLaboratoire de l’Accélérateur Linéaire, Université de Paris-Sud, INP-CNRS, F-91405 Orsay Cedex, France, Ph. HeusseLaboratoire de l’Accélérateur Linéaire, Université de Paris-Sud, INP-CNRS, F-91405 Orsay Cedex, France, P. JanotLaboratoire de l’Accélérateur Linéaire, Université de Paris-Sud, INP-CNRS, F-91405 Orsay Cedex, France, D.W. KimLaboratoire de l’Accélérateur Linéaire, Université de Paris-Sud, INP-CNRS, F-91405 Orsay Cedex, France, F. Le DiberderLaboratoire de l’Accélérateur Linéaire, Université de Paris-Sud, INP-CNRS, F-91405 Orsay Cedex, France, J. LefrançoisLaboratoire de l’Accélérateur Linéaire, Université de Paris-Sud, INP-CNRS, F-91405 Orsay Cedex, France, A.-M. LutzLaboratoire de l’Accélérateur Linéaire, Université de Paris-Sud, INP-CNRS, F-91405 Orsay Cedex, France, J.-J. VeilletLaboratoire de l’Accélérateur Linéaire, Université de Paris-Sud, INP-CNRS, F-91405 Orsay Cedex, France, I. VideauLaboratoire de l’Accélérateur Linéaire, Université de Paris-Sud, INP-CNRS, F-91405 Orsay Cedex, France, Z. ZhangLaboratoire de l’Accélérateur Linéaire, Université de Paris-Sud, INP-CNRS, F-91405 Orsay Cedex, France, F. ZomerLaboratoire de l’Accélérateur Linéaire, Université de Paris-Sud, INP-CNRS, F-91405 Orsay Cedex, France, D. AbbaneoDipartimento di Fisica dell’Università, INFN Sezione di Pisa, e Scuola Normale Superiore, 1-56010 Pisa, Italy, S.R. AmendoliaDipartimento di Fisica dell’Università, INFN Sezione di Pisa, e Scuola Normale Superiore, 1-56010 Pisa, Italy, G. BagliesiDipartimento di Fisica dell’Università, INFN Sezione di Pisa, e Scuola Normale Superiore, 1-56010 Pisa, Italy, G. BatignaniDipartimento di Fisica dell’Università, INFN Sezione di Pisa, e Scuola Normale Superiore, 1-56010 Pisa, Italy, L. BosisioDipartimento di Fisica dell’Università, INFN Sezione di Pisa, e Scuola Normale Superiore, 1-56010 Pisa, Italy, U. BottigliDipartimento di Fisica dell’Università, INFN Sezione di Pisa, e Scuola Normale Superiore, 1-56010 Pisa, Italy, C. BradaschiaDipartimento di Fisica dell’Università, INFN Sezione di Pisa, e Scuola Normale Superiore, 1-56010 Pisa, Italy, M. CarpinelliDipartimento di Fisica dell’Università, INFN Sezione di Pisa, e Scuola Normale Superiore, 1-56010 Pisa, Italy, M.A. CiocciDipartimento di Fisica dell’Università, INFN Sezione di Pisa, e Scuola Normale Superiore, 1-56010 Pisa, Italy, R. Dell’OrsoDipartimento di Fisica dell’Università, INFN Sezione di Pisa, e Scuola Normale Superiore, 1-56010 Pisa, Italy, I. FerranteDipartimento di Fisica dell’Università, INFN Sezione di Pisa, e Scuola Normale Superiore, 1-56010 Pisa, Italy, F. FidecaroDipartimento di Fisica dell’Università, INFN Sezione di Pisa, e Scuola Normale Superiore, 1-56010 Pisa, Italy, L. FoàDipartimento di Fisica dell’Università, INFN Sezione di Pisa, e Scuola Normale Superiore, 1-56010 Pisa, Italy, E. FocardiDipartimento di Fisica dell’Università, INFN Sezione di Pisa, e Scuola Normale Superiore, 1-56010 Pisa, Italy, F. FortiDipartimento di Fisica dell’Università, INFN Sezione di Pisa, e Scuola Normale Superiore, 1-56010 Pisa, Italy, C. GattoDipartimento di Fisica dell’Università, INFN Sezione di Pisa, e Scuola Normale Superiore, 1-56010 Pisa, Italy, A. GiassiDipartimento di Fisica dell’Università, INFN Sezione di Pisa, e Scuola Normale Superiore, 1-56010 Pisa, Italy, M.A. GiorgiDipartimento di Fisica dell’Università, INFN Sezione di Pisa, e Scuola Normale Superiore, 1-56010 Pisa, Italy, F. LigabueDipartimento di Fisica dell’Università, INFN Sezione di Pisa, e Scuola Normale Superiore, 1-56010 Pisa, Italy, E.B. MannelliDipartimento di Fisica dell’Università, INFN Sezione di Pisa, e Scuola Normale Superiore, 1-56010 Pisa, Italy, P.S. MarrocchesiDipartimento di Fisica dell’Università, INFN Sezione di Pisa, e Scuola Normale Superiore, 1-56010 Pisa, Italy, A. MessineoDipartimento di Fisica dell’Università, INFN Sezione di Pisa, e Scuola Normale Superiore, 1-56010 Pisa, Italy, L. MonetaDipartimento di Fisica dell’Università, INFN Sezione di Pisa, e Scuola Normale Superiore, 1-56010 Pisa, Italy, F. PallaDipartimento di Fisica dell’Università, INFN Sezione di Pisa, e Scuola Normale Superiore, 1-56010 Pisa, Italy, G. SanguinettiDipartimento di Fisica dell’Università, INFN Sezione di Pisa, e Scuola Normale Superiore, 1-56010 Pisa, Italy, J. SteinbergerDipartimento di Fisica dell’Università, INFN Sezione di Pisa, e Scuola Normale Superiore, 1-56010 Pisa, Italy, R. TenchiniDipartimento di Fisica dell’Università, INFN Sezione di Pisa, e Scuola Normale Superiore, 1-56010 Pisa, Italy, G. TonelliDipartimento di Fisica dell’Università, INFN Sezione di Pisa, e Scuola Normale Superiore, 1-56010 Pisa, Italy, G. TriggianiDipartimento di Fisica dell’Università, INFN Sezione di Pisa, e Scuola Normale Superiore, 1-56010 Pisa, Italy, C. VanniniDipartimento di Fisica dell’Università, INFN Sezione di Pisa, e Scuola Normale Superiore, 1-56010 Pisa, Italy, A. VenturiDipartimento di Fisica dell’Università, INFN Sezione di Pisa, e Scuola Normale Superiore, 1-56010 Pisa, Italy, P.G. VerdiniDipartimento di Fisica dell’Università, INFN Sezione di Pisa, e Scuola Normale Superiore, 1-56010 Pisa, Italy, J. WalshDipartimento di Fisica dell’Università, INFN Sezione di Pisa, e Scuola Normale Superiore, 1-56010 Pisa, Italy, J.M. CarterDepartment of Physics, Royal Holloway and Bedford New College, University of London, Surrey TW20OEX, UK, M.G. GreenDepartment of Physics, Royal Holloway and Bedford New College, University of London, Surrey TW20OEX, UK, P.V. MarchDepartment of Physics, Royal Holloway and Bedford New College, University of London, Surrey TW20OEX, UK, T. MedcalfDepartment of Physics, Royal Holloway and Bedford New College, University of London, Surrey TW20OEX, UK, I.S. QuaziDepartment of Physics, Royal Holloway and Bedford New College, University of London, Surrey TW20OEX, UK, J.A. StrongDepartment of Physics, Royal Holloway and Bedford New College, University of London, Surrey TW20OEX, UK, R.M. ThomasDepartment of Physics, Royal Holloway and Bedford New College, University of London, Surrey TW20OEX, UK, L.R. WestDepartment of Physics, Royal Holloway and Bedford New College, University of London, Surrey TW20OEX, UK, T. WildishDepartment of Physics, Royal Holloway and Bedford New College, University of London, Surrey TW20OEX, UK, D.R. BotterillParticle Physics Department, Rutherford Appleton Laboratory, Chilton, Didcot, OXON 0X11 OQX, UK, R.W. ClifftParticle Physics Department, Rutherford Appleton Laboratory, Chilton, Didcot, OXON 0X11 OQX, UK, T.R. EdgecockParticle Physics Department, Rutherford Appleton Laboratory, Chilton, Didcot, OXON 0X11 OQX, UK, M. EdwardsParticle Physics Department, Rutherford Appleton Laboratory, Chilton, Didcot, OXON 0X11 OQX, UK, S.M. FisherParticle Physics Department, Rutherford Appleton Laboratory, Chilton, Didcot, OXON 0X11 OQX, UK, T.J. JonesParticle Physics Department, Rutherford Appleton Laboratory, Chilton, Didcot, OXON 0X11 OQX, UK, P.R. NortonParticle Physics Department, Rutherford Appleton Laboratory, Chilton, Didcot, OXON 0X11 OQX, UK, D.P. SalmonParticle Physics Department, Rutherford Appleton Laboratory, Chilton, Didcot, OXON 0X11 OQX, UK, J.C. ThompsonParticle Physics Department, Rutherford Appleton Laboratory, Chilton, Didcot, OXON 0X11 OQX, UK, B. Bloch-DevauxDépartement de Physique des Particules Elémentaires, CEN-Saclay, F-91191 Gif-sur-Yvette Cedex, France, P. ColasDépartement de Physique des Particules Elémentaires, CEN-Saclay, F-91191 Gif-sur-Yvette Cedex, France, C. KlopfensteinDépartement de Physique des Particules Elémentaires, CEN-Saclay, F-91191 Gif-sur-Yvette Cedex, France, E. LocciDépartement de Physique des Particules Elémentaires, CEN-Saclay, F-91191 Gif-sur-Yvette Cedex, France, S. LoucatosDépartement de Physique des Particules Elémentaires, CEN-Saclay, F-91191 Gif-sur-Yvette Cedex, France, E. MonnierDépartement de Physique des Particules Elémentaires, CEN-Saclay, F-91191 Gif-sur-Yvette Cedex, France, P. PerezDépartement de Physique des Particules Elémentaires, CEN-Saclay, F-91191 Gif-sur-Yvette Cedex, France, J.A. PerlasDépartement de Physique des Particules Elémentaires, CEN-Saclay, F-91191 Gif-sur-Yvette Cedex, France, F. PerrierDépartement de Physique des Particules Elémentaires, CEN-Saclay, F-91191 Gif-sur-Yvette Cedex, France, J. RanderDépartement de Physique des Particules Elémentaires, CEN-Saclay, F-91191 Gif-sur-Yvette Cedex, France, J.-F. RenardyDépartement de Physique des Particules Elémentaires, CEN-Saclay, F-91191 Gif-sur-Yvette Cedex, France, A. RoussarieDépartement de Physique des Particules Elémentaires, CEN-Saclay, F-91191 Gif-sur-Yvette Cedex, France, J.-P. SchullerDépartement de Physique des Particules Elémentaires, CEN-Saclay, F-91191 Gif-sur-Yvette Cedex, France, J. SchwindlingDépartement de Physique des Particules Elémentaires, CEN-Saclay, F-91191 Gif-sur-Yvette Cedex, France, B. VallageDépartement de Physique des Particules Elémentaires, CEN-Saclay, F-91191 Gif-sur-Yvette Cedex, France, J.G. AshmanDepartment of Physics, University of Sheffield, Sheffield S37RH, UK, C.N. BoothDepartment of Physics, University of Sheffield, Sheffield S37RH, UK, C. ButtarDepartment of Physics, University of Sheffield, Sheffield S37RH, UK, R. CarneyDepartment of Physics, University of Sheffield, Sheffield S37RH, UK, S. CartwrightDepartment of Physics, University of Sheffield, Sheffield S37RH, UK, F. CombleyDepartment of Physics, University of Sheffield, Sheffield S37RH, UK, M. DinsdaleDepartment of Physics, University of Sheffield, Sheffield S37RH, UK, M. DogruDepartment of Physics, University of Sheffield, Sheffield S37RH, UK, F. HatfieldDepartment of Physics, University of Sheffield, Sheffield S37RH, UK, J. MartinDepartment of Physics, University of Sheffield, Sheffield S37RH, UK, D. ParkerDepartment of Physics, University of Sheffield, Sheffield S37RH, UK, P. ReevesDepartment of Physics, University of Sheffield, Sheffield S37RH, UK, L.F. ThompsonDepartment of Physics, University of Sheffield, Sheffield S37RH, UK, E. BarberioFachbereich Physik, Universität Siegen, W-5900 Siegen, Federal Republic of Germany, S. BrandtFachbereich Physik, Universität Siegen, W-5900 Siegen, Federal Republic of Germany, H. BurkhardtFachbereich Physik, Universität Siegen, W-5900 Siegen, Federal Republic of Germany, C. GrupenFachbereich Physik, Universität Siegen, W-5900 Siegen, Federal Republic of Germany, H. MeinhardFachbereich Physik, Universität Siegen, W-5900 Siegen, Federal Republic of Germany, L. MirabitoFachbereich Physik, Universität Siegen, W-5900 Siegen, Federal Republic of Germany, U. SchäferFachbereich Physik, Universität Siegen, W-5900 Siegen, Federal Republic of Germany, H. SeywerdFachbereich Physik, Universität Siegen, W-5900 Siegen, Federal Republic of Germany, G. ApollinariDipartimento di Fisica, Université di Trieste e INFN Sezione di Trieste, 1-34127 Trieste, Italy, G. GianniniDipartimento di Fisica, Université di Trieste e INFN Sezione di Trieste, 1-34127 Trieste, Italy, B. GobboDipartimento di Fisica, Université di Trieste e INFN Sezione di Trieste, 1-34127 Trieste, Italy, F. LielloDipartimento di Fisica, Université di Trieste e INFN Sezione di Trieste, 1-34127 Trieste, Italy, F. RagusaDipartimento di Fisica, Université di Trieste e INFN Sezione di Trieste, 1-34127 Trieste, Italy, L. RolandiDipartimento di Fisica, Université di Trieste e INFN Sezione di Trieste, 1-34127 Trieste, Italy, U. StieglerDipartimento di Fisica, Université di Trieste e INFN Sezione di Trieste, 1-34127 Trieste, Italy, L. BellantoniDepartment of Physics, University of Wisconsin, Madison, WI53706, USA, X. ChenDepartment of Physics, University of Wisconsin, Madison, WI53706, USA, D. CinabroDepartment of Physics, University of Wisconsin, Madison, WI53706, USA, J.S. ConwayDepartment of Physics, University of Wisconsin, Madison, WI53706, USA, D.F. CowenDepartment of Physics, University of Wisconsin, Madison, WI53706, USA, Z. FengDepartment of Physics, University of Wisconsin, Madison, WI53706, USA, D.P.S. FergusonDepartment of Physics, University of Wisconsin, Madison, WI53706, USA, Y.S. GaoDepartment of Physics, University of Wisconsin, Madison, WI53706, USA, J. GrahlDepartment of Physics, University of Wisconsin, Madison, WI53706, USA, J.L. HartonDepartment of Physics, University of Wisconsin, Madison, WI53706, USA, J.E. JacobsenDepartment of Physics, University of Wisconsin, Madison, WI53706, USA, R.C. JaredDepartment of Physics, University of Wisconsin, Madison, WI53706, USA, R.P. JohnsonDepartment of Physics, University of Wisconsin, Madison, WI53706, USA, B.W. Le ClaireDepartment of Physics, University of Wisconsin, Madison, WI53706, USA, Y.B. PanDepartment of Physics, University of Wisconsin, Madison, WI53706, USA, J.R. PaterDepartment of Physics, University of Wisconsin, Madison, WI53706, USA, Y. SaadiDepartment of Physics, University of Wisconsin, Madison, WI53706, USA, V. SharmaDepartment of Physics, University of Wisconsin, Madison, WI53706, USA, Z.H. ShiDepartment of Physics, University of Wisconsin, Madison, WI53706, USA, Y.H. TangDepartment of Physics, University of Wisconsin, Madison, WI53706, USA, A.M. WalshDepartment of Physics, University of Wisconsin, Madison, WI53706, USA, J.A. WearDepartment of Physics, University of Wisconsin, Madison, WI53706, USA, F.V. WeberDepartment of Physics, University of Wisconsin, Madison, WI53706, USA, M.H. WhitneyDepartment of Physics, University of Wisconsin, Madison, WI53706, USA, Sau Lan WuDepartment of Physics, University of Wisconsin, Madison, WI53706, USA and G. ZobernigDepartment of Physics, University of Wisconsin, Madison, WI53706, USAhttps://doi.org/10.1142/9789811264436_0023Cited by:0 PreviousNext AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsRecommend to Library ShareShare onFacebookTwitterLinked InRedditEmail Abstract: The properties of the Z resonance are measured on the basis of 190000 Z decays into fermion pairs collected with the ALEPH detector at LEP. Assuming lepton universality, Mz = (91.182 ± 0.009exp ± 0.020L: P) GeV, Γz=(2484 ± 17) MeV, σhad 0=(41.44±0.36) nb, and Γhad/Γℓℓ=21.00±0.20. The corresponding number of light neutrino species is 2.97 ±0.07. The forward-backward asymmetry in leptonic decays is used to determine the ratio of vector to axial-vector coupling constants of leptons: gV2(MZ2)/gA2(MZ2)=0.0072±0.0027. Combining these results with ALEPH results on quark charge and b b¯ asymmetries, and τ polarization, sin2θW(MZ2) =0.2312±0.0018. In the context of the Minimal Standard Model, limits are placed on the top-quark mass. Reprinted by permission from Springer Nature: ALEPH Collaboration (D. Decamp et al.), Z. Phys. C 53, 1–20 (1992). ©1992. FiguresReferencesRelatedDetails Memorial Volume for Jack SteinbergerMetrics History PDF download

Operation of the time projection chamber of the ALEPH experiment at LEP requires a high-purity argon/methane gas mixture supplied to the detector under stable conditions to ensure minimum signal attenuation throughout the 43 m3 detector volume (max. 2.2 m drift length) and maintain near-constant electron drift velocity in the gas over extended periods of time. Design considerations for a gas system to fulfil these conditions are presented and details given of the construction, operational aspects and of the achieved performance.

The readout of the Aleph time projection chamber (TPC) relies on a set of 72 time projection processors (TPPs), which are based on a Motorola 68020 microprocessor running a real-time operating system. The advanced processing capabilities of the TPPs allow them to perform in parallel a number of tasks, both during and outside of data acquisition, which are outlined. The management and control of such a large number of intelligent devices is presented. The discussion covers the hardware configuration of the TPPs; the software running the TPPs; their management, status, and control; exception handling and message logging; and the TPP monitoring tasks.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Over the next decade or two, an impressive array of scientific instruments at the Tevatron, RHIC (Relativistic Heavy Ion Collider) and LHC (Large Hadron collider), LIGO (Laser Interferometer Gravitational Observatory) and SDSS (Sloan Digital Sky Survey), to name a few, will usher in the most comprehensive program of study of the fundamental forces of nature and the structure of the universe. Major discoveries are anticipated. But, it is our conviction that the pace of discoveries will be severely impeded unless a concerted effort is made to deploy and employ advanced computing techniques to handle, process and analyze the unprecedented amounts of data. The workshop followed four main tracks: Artificial Intelligence (neural networks and other adaptive multivariate methods); Innovative Software Algorithms and Tools; Symbolic Problem Solving; and Very Large Scale Computing.The workshop covered applications in high energy physics, astrophysics, accelerator physics and nuclear physics. Topics included are: uses of C++ in scientific computing, large scale simulations, advanced analysis environments, worldwide computing; artificial intelligence: online application of neural networks, applications in data analysis, theoretical aspects innovative software algorithms and tools: online monitoring and controls, physics analysis and reconstruction algorithms, pattern recognition techniques, common libraries, grid and distributed computing techniques; symbolic problem solving: Freynman diagram algorithms and tools, symbolic manipulation via function objects, symbolic techniques for Feynman diagrams, multi-loop calculations and results; very large scale computing: online monitoring and controls, analysis farms and DAQ systems, grid architectures.

The Aleph detector is installed on the LEP electron-positron storage ring. Its central tracking detector, a time projection chamber (TPC), has about 50000 channels of sampling electronics. The digitized signals are processed by 72 double-width Fastbus modules built around an MC 68020 processor. The time projection processor is described, and the solutions, both hardware and software, adopted to run and manage such a complex system in a Fastbus-VAX environment are discussed. Practical experience with the system is reported.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

The tracking performance of the ALEPH time projection chamber (TPC) has been studied using the data taken during the LEP (Large Electron-Positron Collider) running periods in 1989 and 1990. After careful correction of residual distortions and optimization of coordinate reconstruction algorithms, a single coordinate resolution of 173 mu m in the azimuthal and 740 mu m in the longitudinal direction is achieved. This results in a momentum resolution for the TPC alone of Delta p/p/sup 2/=0.0012 (GeV/c)/sup -1/. In combination with the ALEPH inner tracking chamber (ITC), a total momentum resolution of Delta p/p/sup 2/=0.0008 (GeV/c)/sup -1/, close to the design specifications, is reached.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Since CP violation was first observed in the decay of the long-lived neutral kaon into two pions [1], it remains one of the enigmas in particle physics. Whilst CP violation is manifest in neutral kaon decays, the search for CP-violating effects has elsewhere been unsuccessful. In the phenomenology of CP violation in the neutral kaon system [2], the short- and long-lived mass eigenstates are usually defined in terms of the CP eigenstates K1 (CP = + 1) and K2 (CP = - 1) as Ks ≈ K1 + ?K2 and KL ≈ K2 + ?K1. The parameter ? describes CP violation induced by kaon state-mixing. Direct CP violation may also occur in the decay of K2 into two pions with a relative amplitude ?′, which is non-zero in the case of a phase difference between the amplitudes A0 and A2 for the decay into isospin O and 2 states of two pions. Before the present measurement, all experimental results were compatible with ? = 2.27 × 10-3 exp (i 43.70) and with the Superweak Model [3], in which state-mixing is the only source of CP violation and ?′ = 0. In the Standard Model with six weakly interacting quarks [4], direct CP violation as well as state-mixing is introduced by transitions via heavy-quark intermediate states. Based on this, a small, but non-zero, value of ?′ is predicted [5]. To a good approximation, ?′ /? is related to the double ratio R of the relative decay rates of the long- and short-lived neutral kaons into two neutral and two charged pions as Re (?′/?) = 1/6 × (1 - R).

The read-out system for the Aleph central tracking detector, a large Time Projection Chamber (TPC), consists of more than 100 Fastbus crates with approximately 1000 Fastbus modules. The authors briefly present the detector and its associated electronics, followed by a more detailed description of the read-out and control system.