Herrmann, N
Tau production
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Measurement of the Reaction $e^+ e^- \to \tau^+ \tau^-$ at $\sqrt{s}=29$-{GeV}

Gan, K.K. ; Beltrami, I. ; Bylsma, B.G. ; et al.
Phys.Lett.B 153 (1985) 116-120, 1985.
Inspire Record 212773 DOI 10.17182/hepdata.6571

The reaction e + e − → τ + τ − has been measured using the high resolution spectrometer at PEP. The angular distribution shows a forward-backward asymmetry of −(6.1±2.3±0.5)%, corresponding to an axial-vector coupling if g a τ g a e = 0.28 ±0.11± 0.03, in good agreement with the standard model of electroweak interactions. The measured cross section yields ifR ττ = 1.10± 0.03±0.04, consistent with QED and giving QED cutoff parameters of Λ + >92 GeV and Λ − >246 GeV at 95% C.L.

4 data tables
Table 1

Comparison of total tau pair cross section with O(alpha**3) QED prediction.

Table 2

Corrected for acceptance backgraound, and O(alpha**3) radiative effects.

Table 3

Forward-backward asymmetry based on fit to angular distributions.

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Electroweak Effects in $e^+ e^- \to \tau^+ \tau^-$ at 29-{GeV}

Fernandez, E. ; Ford, William T. ; Qi, N. ; et al.
Phys.Rev.Lett. 54 (1985) 1620, 1985.
Inspire Record 207555 DOI 10.17182/hepdata.3267

A high-statistics measurement is presented of the cross section for the process e+e−→τ+τ− at s=29 GeV from the MAC detector at PEP. A fit to the angular distribution of our sample of 10 153 events with |cosθ|<0.9 gives an asymmetry Aττ=−0.055±0.012±0.005 from which we find the product of electron and tau axial-vector weak neutral couplings gAegAτ=0.22±0.05.

4 data tables
Table 1

Data fully corrected up to O(ALPHA**3) radiative effects. Data requested from authors.

Table 2

Data extrapolated to full acceptance.

Table 3

No description provided.

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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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rivet Analysis
A Measurement of the Branching Fraction of the Decay $\Upsilon$ (1s) $\to \tau^+ \tau^-$

The CLEO collaboration Giles, R. ; Hassard, J. ; Hempstead, M. ; et al.
Phys.Rev.Lett. 50 (1983) 877, 1983.
Inspire Record 188803 DOI 10.17182/hepdata.20525

The branching fraction for the decay of the ϒ(1S) into τ paris has been measured to be (3.4±0.4±0.4)%. This result agrees with the previously measured branching ratio of the decay into muon pairs.

2 data tables
Table 1

VISIBLE CROSS SECTIONS IN THE PEAK.

Table 2

No description provided.


Charge Asymmetry and Weak Interaction Effects in $e^+ e^- \to \mu^+ \mu^-$ and $e^+ e^- \to \tau^+ \tau^-$

The TASSO collaboration Brandelik, R. ; Braunschweig, W. ; Gather, K. ; et al.
Phys.Lett.B 110 (1982) 173-180, 1982.
Inspire Record 176719 DOI 10.17182/hepdata.6699

We have measured, at an average centre-of-mass energy of 34.22 GeV a forward-backward charge asymmetry in the reaction e + e − → μ + μ − of value −0.161 ± 0.032. This demonstrates the existence of an axial vector neutral current with coupling strength of g e a g μ a =0.53 ± 0.10. We have also obtained a limit on the vector coupling strength of g e v g μ v <0.12. The Weinberg angle is found to be sin 2 θ W =0.29 +0.09 −0.11 . From the reaction e + e − → τ + τ − we have found g e a g τ a <0.34, g e v g τ v <0.55.

7 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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