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Tests of the standard model and constraints on new physics from measurements of fermion pair production at 189-GeV at LEP

The OPAL collaboration Abbiendi, G. ; Ackerstaff, K. ; Alexander, G. ; et al.
Eur.Phys.J.C 13 (2000) 553-572, 2000.
Inspire Record 504989 DOI 10.17182/hepdata.49123

Cross-sections and angular distributions for hadronic and lepton pair final states in e+e- collisions at a centre-of-mass energy near 189 GeV, measured with the OPAL detector at LEP, are presented and compared with the predictions of the Standard Model. The results are used to measure the energy dependence of the electromagnetic coupling constant alpha_em, and to place limits on new physics as described by four-fermion contact interactions or by the exchange of a new heavy particle such as a sneutrino in supersymmetric theories with R-parity violation. A search for the indirect effects of the gravitational interaction in extra dimensions on the mu+mu- and tau+tau- final states is also presented.

9 data tables
Table 1

Hadronic cross section.

Table 2

The cross sections for hadronic, and muon- and tau-pair production in the two sprime/s regions.

Table 3

The cross sections for electron -pair production with various angular cuts.

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Tests of the standard model and constraints on new physics from measurements of fermion pair production at 189-GeV to 209-GeV at LEP

The OPAL collaboration Abbiendi, G. ; Ainsley, C. ; Akesson, P.F. ; et al.
Eur.Phys.J.C 33 (2004) 173-212, 2004.
Inspire Record 628491 DOI 10.17182/hepdata.43174

Cross-section and angular distributions for hadronic and lepton-pair final states in e+e- collisions at centre-of-mass energies between 189 GeV and 209 GeV, measured with the OPAL detector at LEP, are presented and compared with the predictions of the Standard Model. The measurements are used to determine the electromagnetic coupling constant alphaem at LEP2 energies. In addition, the results are used together with OPAL measurements at 91-183 GeV within the S-matrix formalism to determine the gamma-Z interference term and to make an almost model-independent measurement of the Z mass. Limits on extensions to the Standard Model described by effective four-fermion contact interactions or the addition of a heavy Z boson are also presented.

18 data tables
Table 1

CM energy values.

Table 2

Measured cross section for QUARK QUARKBAR (HADRON) production. The data are corrected to no interference between initial and final state radiation.

Table 3

Measured cross section for MU+ MU- production. The data are corrected to no interference between initial and final state radiation.

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Unique Solution for the Weak Neutral Current Coupling Constants in Purely Leptonic Interactions

The Mark-J collaboration Barber, D.P. ; Becker, U. ; Berghogff, G. ; et al.
Phys.Lett.B 95 (1980) 149-153, 1980.
Inspire Record 154136 DOI 10.17182/hepdata.6235

By combining results from the MARK-J at PETRA on Bhabha scattering, μ + μ - and τ + τ - production with recent world data from neutrino-electron scattering experiments, we determine unique values for the leptonic weak neutral current coupling constants g V and g A in the framework of electroweak models containing a single Z 0 . In contrast to previous analyses, we only use data from purely leptonic interactions, and therefore avoid the inherent uncertainties resulting from the use of hadronic targets. From the MARK-J data alone in the context of the standard SU(2) ⊗ U (1) model of Glashow, Weinberg and Salam, we find sin 2 θ W =0.24±0.11.

3 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.


Update of electroweak parameters from Z decays

The ALEPH collaboration Buskulic, D. ; Decamp, D. ; Goy, C. ; et al.
Z.Phys.C 60 (1993) 71-82, 1993.
Inspire Record 354298 DOI 10.17182/hepdata.47312

Based on 520 000 fermion pairs accumulated during the first three years of data collection by the ALEPH detector at LEP, updated values of the resonance parameters of theZ are determined to beMZ=(91.187±0.009) GeV, ΓZ=(2.501±0.012) GeV, σhad0=(41.60±0.27) nb, andRℓ=20.78±0.13. The corresponding number of light neutrino species isNν=2.97±0.05. The forward-backward asymmetry in lepton-pair decays is used to determine the ratio of vector to axial-vector couplings of leptons:gV2(MZ2)/gA2(MZ2)=0.0052±0.0016. Combining this with ALEPH measurements of theb andc quark asymmetries and τ polarization gives sin2θWeff=0.2326±0.0013. Assuming the minimal Standard Model, and including measurements ofMW/MZ fromp\(\bar p\) colliders and neutrino-nucleon scattering, the mass of the top quark is\(M_{top} = 156 \pm \begin{array}{*{20}c} {22} \\ {25} \\ \end{array} \pm \begin{array}{*{20}c} {17} \\ {22Higgs} \\ \end{array} \) GeV.

15 data tables
Table 1

Data from 1990 running period.

Table 2

Data from 1990 running period.

Table 3

Data from 1990 running period.

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Weak Neutral Currents in e+ e- Collisions at s**(1/2)=29-GeV

Levi, M.E. ; Blocker, C.A. ; Strait, J. ; et al.
Phys.Rev.Lett. 51 (1983) 1941, 1983.
Inspire Record 191845 DOI 10.17182/hepdata.3281

The differential cross sections for lepton pair production in e+e− annihilation at 29 GeV have been measured and found to be in good agreement with the standard model of the electroweak interaction. With the assumption of e−μ−τ universality, the weak neutral-current couplings are determined to be ga2=0.23±0.05 and gv2=0.03±0.04.

8 data tables
Table 1

Numerical values supplied by M.Levi.

Table 2

Data requested from authors.

Table 3

Extrapolated to full angular range.

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