Measurement of the Reactions $e^+ e^- \to \mu^+ \mu^-$ and $e^+ e^- \to \tau^+ \tau^-$ Between $\sqrt{s}=50$-{GeV} and 60.8-{GeV}

The VENUS collaboration Abe, K. ; Amako, K. ; Arai, Y. ; et al.
Z.Phys.C 48 (1990) 13-22, 1990.
Inspire Record 294672 DOI 10.17182/hepdata.38414

The angular distributions of the reactione+e−→μ+μ− ande+e+→τ+τ− have been measured between\(\sqrt s= 50\) and 60.8 GeV with the VENUS detector at TRISTAN. The average total cross section and the forward-backward charge asymmetry for μ-pair production are observed to be 28.3±1.4±0.8 pb and (−29.0−4.8+5.0±0.5)%, and those for τ-pair production are 27.6±1.7±1.0 pb and (−32.8−6.2+6.4±1.5)% at\(\langle \sqrt s \rangle \). These values are consistent with the predictions of the standard model of electroweak interactions.

3 data tables match query

No description provided.

No description provided.

No description provided.


Measurements of cross-section and charge asymmetry for e+ e- ---> mu+ mu- and e+ e- ---> tau+ tau- at s**(1/2) = 57.8-GeV

The AMY collaboration Velissaris, C. ; Lusin, S. ; Chung, Y.S. ; et al.
Phys.Lett.B 331 (1994) 227-235, 1994.
Inspire Record 373861 DOI 10.17182/hepdata.38344

With data corresponding to 142 pb −1 accumulated at s = 57.8 GeV by the AMY detector at TRISTAN we measure the cross section of the reactions e + e − → μ + μ − and e + e − → τ + τ − and the symmetry in the angular distributions. For the lowest order cross section we obtain σ μμ = 27.54 ± 0.65 ± 0.95 pb and σ ττ = 28.27 ± 0.87 ± 0.69 pb, and for the forward-backward asymmetry, A μμ = 0.303 ± 0.027 ± 0.008 and A ττ = −0.291 ± 0.040 ± 0.019. These measurements agree with the standard model. Assuming e − μ − τ univrsality we extract the vector and axial coupling constants | gν | = 0.00 ± 0.09 and | g A | = 0.476 ± 0.024. A fit of data to composite models places lower bounds (95% confidence level) on the compositeness scale of 2–4 TeV.

2 data tables match query

Lowest order cross section and forward-backward asymmetry.

Lowest order cross section and forward-backward asymmetry.


Measurement of the cross-section and forward-backward charge asymmetry for the b and c quark in e+ e- annihilation with inclusive muons at s**(1/2) = 58-GeV.

The TOPAZ collaboration Inoue, Y. ; Miyamoto, A. ; Nakano, E. ; et al.
Eur.Phys.J.C 18 (2000) 273-282, 2000.
Inspire Record 538542 DOI 10.17182/hepdata.43244

We have studied inclusive muon events using all the data collected by the TOPAZ detector at sqrt(s)=58 GeV with an integrated luminosity of 273pb-1. From 1328 inclusive muon events, we measured the ratio R_qq of the cross section for qq-bar production to the total hadronic cross section and forward-backward asymmetry A^q_FB for b and c quarks. The obtained results are R_bb = 0.13+-0.02(stat)+-0.01(syst), R_cc = 0.36+-0.05(stat)+-0.05(syst), A^b_FB = -0.20+-0.16(stat)+-0.01(syst) and A^c_FB = -0.17+-0.14(stat)+-0.02(syst), in fair agreement with a prediction of the standard model.

1 data table match query

Forward-backward asymmetry for a four-parameter fit.


Lepton asymmetry in W decays from anti-p p collisions at S**(1/2) = 1.8-TeV

The CDF collaboration Abe, F. ; Amidei, Dante E. ; Apollinari, G. ; et al.
Phys.Rev.Lett. 68 (1992) 1458-1462, 1992.
Inspire Record 323033 DOI 10.17182/hepdata.19880

The charge asymmetry of leptons from W-boson decay has been measured using p¯p data from the Collider Detector at Fermilab at √s =1.8 TeV. The observed asymmetry is well described by most of the available parton distributions.

3 data tables match query

Electrons in the central region.

Muons in the central region.

Plug electrons.


The Charge asymmetry in W boson decays produced in p anti-p collisions at s**(1/2) = 1.8-TeV

The CDF collaboration Abe, F. ; Albrow, M.G. ; Amidei, D. ; et al.
Phys.Rev.Lett. 74 (1995) 850-854, 1995.
Inspire Record 379592 DOI 10.17182/hepdata.42427

The charge asymmetry has been measured using $19,039W$ decays recorded by the CDF detector during the 1992-93 run of the Tevatron Collider. The asymmetry is sensitive to the ratio of $d$ and $u$ quark distributions to $x<0.01$ at $Q~2 \approx M_W~2$, where nonperturbative effects are minimal. It is found that of the two current sets of parton distributions, those of Martin, Roberts and Stirling (MRS) are favored over the sets most recently produced by the CTEQ collaboration. The $W$ asymmetry data provide a stronger constraints on $d/u$ ratio than the recent measurements of $F_2~{\mu n}/F_2~{\mu p}$ which are limited by uncertainties originating from deutron corrections.

1 data table match query

Charge asymmetry defined as (DSIG(Q=L+)/DYRAP - DSIG(Q=L-)/DYRAP)/ (DSIG(Q=L+)/DYRAP + DSIG(Q=L-)/DYRAP). Here LEPTON are E and MU.


Cross-sections and charge asymmetries for e+ e- ---> mu+ mu- and e+ e- ---> tau+ tau- reactions at s**(1/2) = 52-GeV - 61.4-GeV

The TOPAZ collaboration Howell, B. ; Koltick, D.S. ; Tauchi, T. ; et al.
Phys.Lett.B 291 (1992) 206-212, 1992.
Inspire Record 336076 DOI 10.17182/hepdata.29061

The process e + e − → μ + μ − and e + e − have been studied in the energy range s =52−61.4 GeV , using the TOPAZ detector at TRISTAN. From an integrated luminosity of L = 74.0 pb −1 , lowest-order cross sections and forward-backward asymmetries are measured to be 〈σ μμ 〈 = 25.4±0.9±1.2 pb , 〈A μμ 〉 = (−32.2±3.1±1.1)%, 〈σ ττ 〉 = 27.1±1.1±1.2 pb , 〈A ττ 〉 = (−33.9±4.9±1.0)% , at an average energy of s 〉=57.87 GeV . From the measured assymetry we derive axial vector couplings of a c a μ =0.96±0.09±0.01,and a c a τ =1.01±0.14±0.01±. These results are consistent with standard model expectations. Lower limits in the range 2–5 TeV (95%CL)are placed on compositeness scale parameters for leptons.

1 data table match query

No description provided.


Measurement of d sigma / dM forward backward charge asymmetry for high mass Drell-Yan e+ e- pairs from p anti-p collisions at s**(1/2) = 1.8-TeV

The CDF collaboration Affolder, T. ; Akimoto, H. ; Akopian, A. ; et al.
Phys.Rev.Lett. 87 (2001) 131802, 2001.
Inspire Record 558278 DOI 10.17182/hepdata.42899

We report on a measurement of the mass dependence of the forward-backward charge asymmetry, A_FB, and production cross section dsigma/dM for e+e- pairs with mass M_ee>40 GeV/c2. The data sample consists of 108 pb-1 of p-pbar collisions at sqrt(s)=1.8 TeV taken by the Collider Detector at Fermilab during 1992-1995. The measured asymmetry and dsigma/dM are compared with the predictions of the Standard Model and a model with an extra Z' gauge boson.

1 data table match query

The E+ E- production cross section and the forward-backward asymmetry. The errors contain the statistical and systematic uncertainties combined in quadrature, but not the additional uncertainty of the luminosity.


Charge asymmetry of hadronic events in e+ e- annihilation at s**(1/2) = 57.9-GeV

The TOPAZ collaboration Adachi, I. ; Anazawa, M. ; Doser, M. ; et al.
Phys.Lett.B 255 (1991) 613-622, 1991.
Inspire Record 314203 DOI 10.17182/hepdata.29492

The charge asymmetry of quark jets produced in e + e − annihilations at 〈√ s 〉=57.9 GeV was measured with the TOPAZ detector at TRISTAN. The observed charge asymmetry is +0.091±0.014(stat.)±0.016(sys.). From the measured differential cross section, the axial vector coupling constant averaged over all quark flavors was determined to be 1.09 −0.21 +0.27 . These values are consistent with the standard model predictions. Possible deviations from the standard model were examined in terms of contact interactions, and the lower limits on the compositeness scale parameters were obtained to be 1.2–7.1 TeV at the 95% confidence level.

1 data table match query

No description provided.


MEASUREMENTS OF CROSS-SECTIONS AND CHARGE ASYMMETRIES FOR e+ e- ---> tau+ tau- AND e+ e- ---> mu+ mu- FOR S**(1/2) FROM 52-GeV TO 57-GeV

The AMY collaboration Bacala, A. ; Malchow, R.L. ; Sparks, K. ; et al.
Phys.Lett.B 218 (1989) 112-118, 1989.
Inspire Record 265797 DOI 10.17182/hepdata.51370

Measurements of the differential cross sections for e + e − →μ + μ − and e + e − →τ + τ − at values of s from 52 to 57 GeV are reported. The forward-backward asymmetries and the total cross sections for these reactions are found to be in agreement with predictions of the standard model of the electro-weak interactions. These measurements are used to extract values of the weak coupling constant g v e g v l and g A e g A l , where l = μ or τ .

3 data tables match query

No description provided.

Weighted average of results from data at 52, 55, 56, and 57 GeV.

Axis error includes +- 5/5 contribution ((C=APPROX)//).


Measurements of b quark forward - backward charge asymmetry and axial vector coupling using inclusive muons in e+ e- annihilation at s**(1/2) = 52-GeV - 61.4-Gev

The TOPAZ collaboration Shimonaka, A. ; Fujii, K. ; Miyamoto, A. ; et al.
Phys.Lett.B 268 (1991) 457-464, 1991.
Inspire Record 319034 DOI 10.17182/hepdata.29343

We have collected 122 multi-hadronic inclusive muon events with the TOPAZ detector at 〈 s 〉 = 58.27 GeV with ∫ L d t=40.61 pb −1 . From this event sample we derived the differential cross section for B-hadron productions and determined B-hadron forward-backward asymmetry (A b b ) to be A b b = −0.71 ± 0.34 ( stat ) +0.07 −0.08 ( syst ) . A fit to the differential cross section, after correcting for the effect of B 0 B 0 mixing, yielded the axial-vector coupling constant of the b-quark ( a b ): a b = −1.79 +0.34 −0.32 (stat) +0.15 −0.14 (syst). We also set a 90% confidence level limit of χ <0.37 on the B 0 B 0 mixing parameter.

1 data table match query

No description provided.