An Improved Measurement of Electroweak Couplings From $e^+ e^- \to e^+ e^-$ and $e^+ e^- \to \mu^+ \mu^-$

The TASSO collaboration Althoff, M. ; Braunschweig, W. ; Kirschfink, F.J. ; et al.
Z.Phys.C 22 (1984) 13, 1984.
Inspire Record 193787 DOI 10.17182/hepdata.2111

We present an analysis of electroweak leptonic couplings from high statistics experiments on Bhabha scattering and μ pair production at an energy of 34.5 GeV. The forward-backward charge asymmetry of the μ pairs was measured to be −0.098±0.023±0.005. The data were found to agree well with the standard theory of electroweak interaction giving sin2θW=0.27±0.07. The leptonic weak couplings were determined to begv=0.000±0.170 andgA=−0.481±0.055. The data were also used to investigate a class of composite models for leptons.

2 data tables

No description provided.

No description provided.


Measurement of hadron and lepton-pair production in e+ e- collisions at s**(1/2) = 192-GeV - 208-GeV at LEP.

The L3 collaboration Achard, P. ; Adriani, O. ; Aguilar-Benitez, M. ; et al.
Eur.Phys.J.C 47 (2006) 1-19, 2006.
Inspire Record 704275 DOI 10.17182/hepdata.48637

Hadron production and lepton-pair production in e+e- collisions are studied with data collected with the L3 detector at LEP at centre-of-mass energies sqrt{s}=192-208GeV. Using a total integrated luminosity of 453/pb, 36057 hadronic events and 12863 lepton-pair events are selected. The cross sections for hadron production and lepton-pair production are measured for the full sample and for events where no high-energy initial-state-radiation photon is emitted prior to the collisions. Lepton-pair events are further investigated and forward-backward asymmetries are measured. Finally, the differential cross sections for electron-positron pair-production is determined as a function of the scattering angle. An overall good agreement is found with Standard Model predictions.

21 data tables

Measured hadron cross section for the inclusive data sample.

Measured hadron cross section for the high-energy data sample.

Measured MU+ MU- cross section for the inclusive data sample.

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Measurement and interpretation of fermion-pair production at LEP energies above the Z resonance.

The DELPHI collaboration Abdallah, J. ; Abreu, P. ; Adam, W. ; et al.
Eur.Phys.J.C 45 (2006) 589-632, 2006.
Inspire Record 699726 DOI 10.17182/hepdata.48590

This paper presents DELPHI measurements and interpretations of cross-sections, forward-backward asymmetries, and angular distributions, for the e+e- -> ffbar process for centre-of-mass energies above the Z resonance, from sqrt(s) ~ 130 - 207 GeV at the LEP collider. The measurements are consistent with the predictions of the Standard Model and are used to study a variety of models including the S-Matrix ansatz for e+e- -> ffbar scattering and several models which include physics beyond the Standard Model: the exchange of Z' bosons, contact interactions between fermions, the exchange of gravitons in large extra dimensions and the exchange of sneutrino in R-parity violating supersymmetry.

29 data tables

Measured cross sections and forward-backward asymmetries for non-radiative E+ E- --> E+ E- events.

Differential cross sections for non-radiative E+ E- --> E+ E- events at centre of mass energy 189 GeV.

Differential cross sections for non-radiative E+ E- --> E+ E- events at centre of mass energy 192 GeV.

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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

CM energy values.

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

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

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Measurement of hadron and lepton pair production at 130-GeV less than S**(1/2) less than 189-GeV at LEP

The L3 collaboration Acciarri, M. ; Achard, P. ; Adriani, O. ; et al.
Phys.Lett.B 479 (2000) 101-117, 2000.
Inspire Record 513676 DOI 10.17182/hepdata.48958

We report on measurements of e+e- annihilation into hadrons and lepton pairs. The data have been collected with the L3 detector at LEP at centre-of-mass energies between 130 and 189 GeV. Using a total integrated luminosity of 243.7 pb^-1, 25864 hadronic and 8573 lepton-pair events are selected for the measurement of cross sections and leptonic forward-backward asymmetries. The results are in good agreement with Standard Model predictions.

10 data tables

Measured cross sections for the hadronic events.

Measured cross sections for the muon-pair events.

Measured cross sections for the tau-pair events.

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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

Hadronic cross section.

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

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

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Measurement of the Processes $e^+ e^- \to e^+ e^-$ and $e^+ e^- \to \gamma \gamma$ at {PETRA}

The JADE collaboration Bartel, W. ; Becker, L. ; Bowdery, C. ; et al.
Z.Phys.C 19 (1983) 197, 1983.
Inspire Record 191231 DOI 10.17182/hepdata.45206

Cross sections for the reactionse+e−→e+e− (Bhabha scattering) ande+e−→γγ are measured for center-of-mass (c.m.) energies\(\sqrt s \) between 12.0 and 34.6 GeV. The results agree with the predictions of Quantum Electrodynamics (QED) and the cut-off parameters are determined. From Bhabha scattering at the highest energy,\(\left\langle {\sqrt s } \right\rangle= 34.6 GeV\), the 1 δ limits 0.12<sin2 ϑw<0.38 are obtained for the weak mixing angle. The higher order (α3) QED processese+e−→e+e−γ ande+e−→γγγ are also studied and are found to agree with the α3 QED predictions. A search for excited electrons is carried out by investigating the (e±γ) invariant mass distribution in the reactione+e−→e+e−γ.

3 data tables

Total cross sections.

Angular distribution.

Angular distribution.


Precise measurement of Bhabha scattering at a center-of-mass energy of 57.77-GeV.

The VENUS collaboration Arima, T. ; Odaka, S. ; Ogawa, K. ; et al.
Phys.Rev.D 55 (1997) 19-39, 1997.
Inspire Record 421762 DOI 10.17182/hepdata.38325

Bhabha scattering at a center-of-mass energy of 57.77 GeV has been measured using the VENUS detector at KEK TRISTAN. The precision is better than 1% in scattering angle regions of |cosθ|⩽0.743 and 0.822⩽cosθ⩽0.968. A model-independent scattering-angle distribution is extracted from the measurement. The distribution is in good agreement with the prediction of the standard electroweak theory. The sensitivity to underlying theories is examined, after unfolding the photon-radiation effect. The q2 dependence of the photon vacuum polarization, frequently interpreted as a running of the QED fine-structure constant, is directly observed with a significance of three standard deviations. The Z0 exchange effect is clearly seen when the distribution is compared with the prediction from QED (photon exchanges only). The agreement with the standard theory leads us to constraints on extensions of the standard theory. In all quantitative discussions, correlations in the systematic error between angular bins are taken into account by employing an error matrix technique.

1 data table

Cross section is integrated over the cos(theta ) bin.


Test of the four-fermion contact interaction in e+ e- collisions at 130-GeV to 140-GeV.

The OPAL collaboration Alexander, G. ; Allison, John ; Altekamp, N. ; et al.
Phys.Lett.B 387 (1996) 432-442, 1996.
Inspire Record 421997 DOI 10.17182/hepdata.47754

The differential cross-sections for e + e − → e + e − , e + e − → μ + μ − and e + e − → τ + τ − , and the total cross-section for e + e − → qq̄ at centre-of-mass energies of 130–140 GeV were studied using about 5 pb −1 of data collected with the OPAL detector at LEP in October and November 1995. The results are in agreement with the Standard Model predictions. Four-fermion contact interaction models were fitted to the data and lower limits were obtained on the energy scale Λ at the 95% confidence level.

3 data tables

No description provided.

No description provided.

No description provided.


Limits on Electron Compositeness From Bhabha Scattering

Z.Phys.C 51 (1991) 143-148, 1991.
Inspire Record 284562 DOI 10.17182/hepdata.14982
1 data table

No description provided.