The
OPAL
collaboration
Acton, P.D.
;
Alexander, G.
;
Allison, John
;
*et al. *

Z.Phys.C 58 (1993) 219-238, 1993.

https://inspirehep.net/literature/352696
Inspire Record
352696
DOI
10.17182/hepdata.14495
https://doi.org/10.17182/hepdata.14495
New measurements of the hadronic and leptonic cross sections and of the leptonic forward-backward asymmetries ine+e− collisions are presented. The analysis includes data recorded up to the end of 1991 by the OPAL experiment at LEP, with centre-of-mass energies within ±3 GeV of the Z0 mass. The results are based on a recorded total of 454 000 hadronic and 58 000 leptonic events. A model independent analysis of Z0 parameters based on an extension of the improved Born approximation is presented leading to test of lepton universality and an interpretation of the results within the Standard Model framework. The determination of the mass and width of the Z0 benefit from an improved understanding of the LEP energy calibration.

5
data tables
match query

Additional systematic error of 0.003.

Forward-backward asymmetry from counting number of events. Additional systematic error of 0.003.

2
data tables
match query

Asymmetries. Systematic error is 1 pct.

Asymmetries. Systematic error is 1 pct.

The
OPAL
collaboration
Akrawy, M.Z.
;
Alexander, G.
;
Allison, J.
;
*et al. *

Phys.Lett.B 247 (1990) 458-472, 1990.

https://inspirehep.net/literature/297139
Inspire Record
297139
DOI
10.17182/hepdata.29630
https://doi.org/10.17182/hepdata.29630
The couplings of the Z 0 to charged leptons are studied using measurements of the lepton pair cross sections and forward-backward asymmetries at centre of mass energies near to the mass of the Z 0 . The data are consistent with lepton universality. Using a parametrisation of the lepton pair differential cross section which assumes that the Z 0 has only vector and axial couplings to leptons, the charged leptonic partial decay width of the Z 0 is determined to be Г ol+ol− = 83.1±1.9 MeV and the square of the product of the effective axial vector and vector coupling constants of the Z 0 to charged leptons to be a ̌ 2 ol v ̌ 2 ol = 0.0039± 0.0083 , in agreement with the standard model. A parametrisation in the form of the improved Born approximation gives effective leptonic axial vector and vector coupling constants a ̌ 2 ol = 0.998±0.024 and v ̌ 2 ol = 0.0044±0.0083 . In the framework of the standard model, the values of the parameters ϱ z and sin 2 θ w are found to be 0.998±0.024 and 0.233 +0.045 −0.012 respectively. Using the relationship in the minimal standard model between ϱ z and sin 2 θ w , the results sin 2 θ SM w = 0.233 +0.007 −0.006 is obtained. Our previously published measurement of the ratio of the hadronic to the leptonic partial width of the Z 0 is update: R z = 21.72 +0.71 −0.65 .

3
data tables
match query

Forward-backward asymmetry corrected for kinematic cuts. Errors have systematics folded.

Forward-backward asymmetry. Statistical errors only.

Forward-backward asymmetry. Statistical errors only.

The
CELLO
collaboration
Behrend, H.J.
;
Chen, C.
;
Fenner, H.
;
*et al. *

Z.Phys.C 16 (1983) 301, 1983.

https://inspirehep.net/literature/180756
Inspire Record
180756
DOI
10.17182/hepdata.16385
https://doi.org/10.17182/hepdata.16385
Differential cross sections fore+e−→e+e−, τ+, τ- measured with the CELLO detector at\(\left\langle {\sqrt s } \right\rangle= 34.2GeV\) have been analyzed for electroweak contributions. Vector and axial vector coupling constants were obtained in a simultaneous fit to the three differential cross sections assuming a universal weak interaction for the charged leptons. The results,v2=−0.12±0.33 anda2=1.22±0.47, are in good agreement with predictions from the standardSU(2)×U(1) model for\(\sin ^2 \theta _w= 0.228\). Combining this result with neutrino-electron scattering data gives a unique axial vector dominated solution for the leptonic weak couplings. Assuming the validity of the standard model, a value of\(\sin ^2 \theta _w= 0.21_{ - 0.09}^{ + 0.14}\) is obtained for the electroweak mixing angle. Additional vector currents are not observed (C<0.031 is obtained at the 95% C.L.).

1
data table
match query

The
L3
collaboration
Adeva, B.
;
Adriani, O.
;
Aguilar-Benitez, M.
;
*et al. *

L3-005, 1990.

https://inspirehep.net/literature/294576
Inspire Record
294576
DOI
10.17182/hepdata.29691
https://doi.org/10.17182/hepdata.29691
None

1
data table
match query

No description provided.

The
DELPHI
collaboration
Abdallah, J.
;
Abreu, P.
;
Adam, W.
;
*et al. *

Eur.Phys.J.C 45 (2006) 589-632, 2006.

https://inspirehep.net/literature/699726
Inspire Record
699726
DOI
10.17182/hepdata.48590
https://doi.org/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.

5
data tables
match query

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

Measured cross sections and forward-backward asymmetries for inclusive E+ E- --> MU+ MU- events.

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

The
ALEPH
collaboration
Decamp, D.
;
Deschizeaux, B.
;
Goy, C.
;
*et al. *

Z.Phys.C 48 (1990) 365-392, 1990.

https://inspirehep.net/literature/298414
Inspire Record
298414
DOI
10.17182/hepdata.47314
https://doi.org/10.17182/hepdata.47314
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 findMZ=(91.193±0.016exp±0.030LEP) GeV, ΓZ=(2497±31) MeV, σhad0=(41.86±0.66)nb, and for the partial widths Γinv=(489±24) MeV, Γhad(1754±27) MeV, Γee=(85.0±1.6)MeV, Γμμ=(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,gv2(MZ2)=(0.12±0.12)×10−2 andgA2(MZ2)=0.2528±0.0040. The number of light neutrino species isNν=2.91±0.13; the electroweak mixing angle is sin2θW(MZ2)=0.2291±0.0040.

4
data tables
match query

No description provided.

No description provided.

No description provided.

The
L3
collaboration
Acciarri, M.
;
Adam, A.
;
Adriani, O.
;
*et al. *

Z.Phys.C 62 (1994) 551-576, 1994.

https://inspirehep.net/literature/374696
Inspire Record
374696
DOI
10.17182/hepdata.48198
https://doi.org/10.17182/hepdata.48198
We report on the measurement of the leptonic and hadronic cross sections and leptonic forward-backward asymmetries at theZ peak with the L3 detector at LEP. The total luminosity of 40.8 pb−1 collected

12
data tables
match query

Bender, D.
;
Derrick, M.
;
Fernandez, E.
;
*et al. *

Phys.Rev.D 30 (1984) 515, 1984.

https://inspirehep.net/literature/199464
Inspire Record
199464
DOI
10.17182/hepdata.23593
https://doi.org/10.17182/hepdata.23593
During the initial data run with the High Resolution Spectrometer (HRS) at SLAC PEP, an integrated luminosity of 19.6 pb−1 at a center-of-mass energy of 29 GeV was accumulated. The data on Bhabha scattering and muon pair production are compared with the predictions of QED and the standard model of electroweak interactions. The measured forward-backward charge asymmetry in the angular distribution of muon pairs is -8.4%±4.3%. A comparison between the data and theoretical predictions places limits on alternative descriptions of leptons and their interactions. The existence of heavy electronlike or photonlike objects that alter the structure of the QED vertices or modify the propagator are studied in terms of the QED cutoff parameters. The Bhabha-scattering results give a lower limit on a massive photon and upper limits on the effective size of the electron of Λ+>121 GeV and Λ−>118 GeV at the 95% confidence level. Muon pair production yields Λ+>172 GeV and Λ−>172 GeV. If electrons have substructure, the magnitude and character of the couplings of the leptonic constituents affects the Bhabha-scattering angular distributions to such an extent that limits on the order of a TeV can be extracted on the effective interaction length of the components. For models in which the constituents interact with vector couplings of strength g24π∼1, the energy scale ΛVV for the contact interaction is measured to be greater than 1419.0 GeV at the 95% confidence level. We set limits on the production of supersymmetric scalar electrons through s-channel single-photon annihilation and t-channel inelastic scattering. Using events with two noncollinear electrons and no other charged or observed neutral particles in the final state, we see one event which is consistent with a simple supersymmetric model but which is also consistent with QED. This allows us to exclude the scalar electron to 95% confidence level in the mass range 1.8 to 14.2 GeV/c2.

1
data table
match query

Forward-backward asymmetry from full angular range.

The
JADE
collaboration
Bartel, W.
;
Cords, D.
;
Dittmann, P.
;
*et al. *

Phys.Lett.B 99 (1981) 281-286, 1981.

https://inspirehep.net/literature/156813
Inspire Record
156813
DOI
10.17182/hepdata.27121
https://doi.org/10.17182/hepdata.27121
The processes e + e − → e + e − and μ + μ − have been studied at PETRA using the JADE detector. The data, which were collected at s -values of up to 1300 GeV 2 have been analysed in terms of an electro-weak extension of QED to obtain values for the weak vector and axial vector couplings in the lepton sector. The values obtained agree with the predictions of the standard Salam-Weinberg model and the data are further analysed in terms of this model to obtain the limits 0.10 < sin 2 ϑ w < 0.40 (68% CL). The mass of the neutral weak gauge boson is deduced to be greater than 51 GeV/ c 2 .

1
data table
match query

No description provided.