Measurement of electroweak parameters from Z decays into Fermion pairs

The ALEPH collaboration Decamp, D. ; Deschizeaux, B. ; Goy, C. ; et al.
Z.Phys.C 48 (1990) 365-392, 1990.
Inspire Record 298414 DOI 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.

8 data tables

Hadronic cross section from the charged track selection trigger.

Hadronic cross section from the calorimeter selection trigger.

Averaged hadronic cross section.

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A MEASUREMENT OF THE Z0 LEPTONIC PARTIAL WIDTHS AND THE FORWARD - BACKWARD ASYMMETRY

The L3 collaboration Adeva, B. ; Adriani, O. ; Aguilar-Benitez, M. ; et al.
L3-005, 1990.
Inspire Record 294576 DOI 10.17182/hepdata.29691

None

4 data tables

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Measurement of $g$(a) and $g(V$), the Neutral Current Coupling Constants to Leptons

The L3 collaboration Adeva, B. ; Adriani, O. ; Aguilar-Benitez, M. ; et al.
Phys.Lett.B 236 (1990) 109-115, 1990.
Inspire Record 283470 DOI 10.17182/hepdata.29715

We have measured both the rates and the forward-backward asymmetry of ℓ + ℓ − from Z 0 →ℓ + ℓ − (where ℓ= μ , τ ) with the L3 detector. We obtained Γ ℓℓ =88±4±3 MeV and the vector neutral current coupling constant, g v =0.00±0.07 and the axial vector neutral current coupling constant, g A =−0.515±0.015.

2 data tables

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Measurement of $e^+ e^- \to \mu^+ \mu^-$: A Test of Electroweak Theories

The Mark-J collaboration Adeva, B. ; Becker, U. ; Becker-Szendy, R. ; et al.
Phys.Rev.Lett. 55 (1985) 665, 1985.
Inspire Record 214607 DOI 10.17182/hepdata.3237

We use the reaction e+e−→μ+μ−, in the Mark J detector at the DESY high-energy e+e− collider PETRA, to test the standard electroweak theory and find good agreement. We also set limits on the parameters of several extended gauge theories.

6 data tables

CROSS SECTION MEASUREMENT RELATIVE TO PREDICTED QED CROSS SECTION.

FORWARD-BACKWARD ASYMMETRY. THE SYSTEMATIC ERROR IN THE ASYMMETRY IS <0.5 PCT.

ANGULAR DISTRIBUTIONS NOT GIVEN IN PAPER. SUPPLIED BY E.DEFFUR.

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Search for New Particles in $e^+ e^-$ Annihilation From 39.79-{GeV} to 45.52-{GeV}

Adeva, B. ; Barber, D.P. ; Becker, U. ; et al.
Phys.Rev.Lett. 53 (1984) 134, 1984.
Inspire Record 199819 DOI 10.17182/hepdata.20429

We have searched for resonances in the reaction e+e−→hadrons, γγ, μμ, and ee, in the energy range 39.79<s<45.52 GeV, using the Mark J detector at PETRA. We obtain stringent upper limits on the production of toponium and particles postulated to explain Z0→leptonpair+γ events observed at the CERN p―p collider. We also set limits on the mass and coupling constant of excited electrons.

1 data table

No description provided.


A Summary of Recent Experimental Results From Mark-$J$: High-energy $e^+ e^-$ Collisions at {PETRA}

The Mark-J collaboration Adeva, B. ; Barber, D.P. ; Becker, U. ; et al.
Phys.Rept. 109 (1984) 131, 1984.
Inspire Record 196567 DOI 10.17182/hepdata.30997

None

6 data tables

DATA ARE CORRECTED FOR TWO-PHOTON AND TAU PRODUCTION EFFECTS, ACCEPTANCE AND QED RADIATIVE EFFECTS UP TO ORDER ALPHA**3. THERE IS ALSO A 6 PCT NORMALISATION ERROR NOT INCLUDED. THE OVERALL AVERAGE VALUE OF R FROM THIS DATA IS 3.88 +- 0.04 +- 0.22.

No description provided.

SEE PRL 55, 665 FOR MOST RECENT VALUES OF THE MU+ MU- CROSS SECTIONS.

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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

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EXPERIMENTAL STUDY OF HEAVY CHARGED LEPTONS AT PETRA

Barber, D.P. ; Becker, U. ; Bei, G.D. ; et al.
Phys.Rev.Lett. 45 (1980) 1904-1907, 1980.
Inspire Record 158858 DOI 10.17182/hepdata.20675

Data from the MARK-J detector on the reactions e+e−→μ+μ−, τ+τ− in the center-of-mass energy range from 12 to 36.7 GeV are presented. The μ, τ radii are shown to be <10−16 cm. A search has been made for the production of a new heavy lepton and for the production of spin-0 supersymmetric partners of the muon. 95%-confidence-level lower limits of 16 GeV for the mass of a new charged heavy lepton and 15 GeV for the mass of the scalar partners of the muon are obtained.

1 data table

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A Test of Universality of Charged Leptons

Barber, D.P. ; Becker, U. ; Benda, H. ; et al.
Phys.Rev.Lett. 43 (1979) 1915, 1979.
Inspire Record 142012 DOI 10.17182/hepdata.20759

Measurements of the reactions e++e−→e++e−, μ++μ−, and τ++τ− at PETRA energies (s12=13,17,27.4,30 and 31.6 GeV) are reported. The results show that these reactions agree well with the predictions of quantum electrodynamics thus determining that all the known charged leptons are pointlike particles to a distance < × 10−16 cm.

2 data tables

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