An improved direct measurement of leptonic coupling asymmetries with polarized Z bosons.

The SLD collaboration Abe, Koya ; Abe, Kenji ; Abe, T. ; et al.
Phys.Rev.Lett. 86 (2001) 1162-1166, 2001.
Inspire Record 534735 DOI 10.17182/hepdata.41720

We present final measurements of the Z boson-lepton coupling asymmetry parameters Ae, Amu, and Atau with the complete sample of polarized Z bosons collected by the SLD detector at the SLAC Linear Collider. From the left-right production and decay polar angle asymmetries in leptonic Z decays we measure Ae = 0.1544 +- 0.0060, Amu = 0.142 +- 0.015, and Atau = 0.136 +- 0.015. Combined with our left-right asymmetry measured from hadronic decays, we find Ae = 0.1516 +- 0.0021. Assuming lepton universality, we obtain a combined effective weak mixing angle of sin**2 theta^{eff}_W = 0.23098 +- 0.00026.

1 data table match query

No description provided.


First measurement of the strange quark asymmetry at the Z0 peak

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adye, T. ; et al.
Z.Phys.C 67 (1995) 1-14, 1995.
Inspire Record 382285 DOI 10.17182/hepdata.48256

None

3 data tables match query

Measured forward backward asymmetries.

Forward-backward s-quark asymmetries from the separate processes.

Final s-quark forward-backward asymmetries.


Measurement of the e+ e- --> b anti-b and e+ e- --> c anti-c forward backward asymmetries at the Z0 resonance

The L3 collaboration Adriani, O. ; Aguilar-Benitez, M. ; Ahlen, S. ; et al.
Phys.Lett.B 292 (1992) 454-462, 1992.
Inspire Record 339089 DOI 10.17182/hepdata.29017

We have measured the forward-backward asymmetry in e + e − → b b and e + e − → c c processes using hadronic events containing muons or electrons. The data sample corresponds to 4100000 hadronic decays of the Z 0 . From a fit to the single lepton and dilepton p and p T spectra, we determine A b b =0.086±0.015±0.007 and A c c =0.083±0.038±0.027 at the effective center-of-mass energy √ s =91.24 GeV. These measurements yield a value of the electroweak mixing angle sin 2 θ w =0.2336±0.0029 .

3 data tables match query

No description provided.

No description provided.

No description provided.


Measurement of the forward - backward asymmetry of e+ e- ---> Z ---> b anti-b using prompt leptons and a lifetime tag

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adye, T. ; et al.
Z.Phys.C 65 (1995) 569-586, 1995.
Inspire Record 382035 DOI 10.17182/hepdata.48318

The forward-backward asymmetry of the processe+e−→Z→b

2 data tables match query

No description provided.

No description provided.


A Measurement of the forward - backward charge asymmetry in hadronic decays of the Z0

The OPAL collaboration Acton, P.D. ; Alexander, G. ; Allison, J. ; et al.
Phys.Lett.B 294 (1992) 436-450, 1992.
Inspire Record 336774 DOI 10.17182/hepdata.29004

We present a measurement of the forward-backward charge asymmetry in hadronic decays of the Z 0 using data collected with the OPAL detector at LEP. The forward-backward charge asymmetry was measured using a weight function method which gave the number of forward events on a statistical basis. In a data sample of 448 942 hadronic Z 0 decays, we have observed a charge asymmetry of A h = 0.040±0.004 (stat.)±0.006 (syst.)±0.002 (B 0 B 0 mix.), taking into account the effect of B 0 B 0 mixing. In the framework of the standard model, this asymmetry corresponds to an effective weak mixing angle averaged over five quark flavours of sin 2 θ W = 0.2321 ± 0.0017 ( stat. ) ± 0.0027 ( syst. ) ± 0.0009 (B 0 B 0 mix.). The result agrees with the value obtained from the Z 0 line shape and lepton pair forward-backward asymmetry.

2 data tables match query

No description provided.

The second systematic error is due to the uncertainty in the correction for B.BBAR mixing which had been applied to the data.


A Measurement of the Z0 ---> b anti-b forward - backward asymmetry

The L3 collaboration Adeva, B. ; Adriani, O. ; Aguilar-Benitez, M. ; et al.
Phys.Lett.B 252 (1990) 713-721, 1990.
Inspire Record 301901 DOI 10.17182/hepdata.29506

We have measured the forward-backward asymmetry in Z 0 → b b decays using hadronic events containing muons and electrons. The data sample corresponds to 118 200 hadronic events at √ s ≈ M z . From a fit to the single and dilepton p and P ⊥ spectra, we determine A b b =0.130 −0.042 +0.044 including the correction for B 0 − B 0 mixing.

2 data tables match query

Observed asymmetry from fit to single and dilepton P and PT spectra assuming no mixing.

Asymmetry corrected for the effects of mixing using the L3 observed mixing parameter chi(B) = 0.178 +0.049,-0.040.


A measurement of the charm and bottom forward-backward asymmetries using D mesons at LEP.

The OPAL collaboration Alexander, G. ; Allison, John ; Altekamp, N. ; et al.
Z.Phys.C 73 (1997) 379-395, 1997.
Inspire Record 421995 DOI 10.17182/hepdata.47946

A measurement of the charm and bottom forward-backward asymmetry in e+e− annihilations is presented at energies on and around the peak of the Z0 resonance. Decays of the Z0 into charm and bottom quarks are tagged using D mesons identified in about 4 million hadronic decays of the Z0 boson recorded with the OPAL detector at LEP between 1990 and 1995. Approximately 33000 D mesons are tagged in seven different decay modes. From these the charm and bottom asymmetries are measured in three energy ranges around the Z0 peak: \(\matrix {A_{\rm FB}^{\rm c}=0.039\pm 0.051\pm 0.009\cr A_{\rm FB}^{\rm c}=0.063\pm 0.012\pm 0.006\cr A_{\rm FB}^{\rm c}=0.158\pm 0.041\pm 0.011}\)\(\matrix {A_{\rm FB}^{\rm b}=0.086\pm 0.108\pm 0.029\cr A_{\rm FB}^{\rm b}=0.094\pm 0.027\pm 0.022\cr A_{\rm FB}^{\rm b}=0.021\pm 0.090\pm 0.026}\)\(\matrix{\langle E_{cm}\rangle =89.45\ {\rm GeV}\cr \langle E_{cm}\rangle =91.22\ {\rm GeV}\cr \langle E_{cm}\rangle =93.00\ {\rm GeV}}\) The results are in agreement with the predictions of the standard model and other measurements at LEP.

1 data table match query

Forward-backward asymmetry.


Polarized Bhabha Scattering and a Precision Measurement of the Electron Neutral Current Couplings

The SLD collaboration Abe, K. ; Abt, I. ; Ahn, C.J. ; et al.
Phys.Rev.Lett. 74 (1995) 2880-2884, 1995.
Inspire Record 376916 DOI 10.17182/hepdata.19647

We present the first measurement of the left-right asymmetry in Bhabha scattering with a polarized electron beam. The effective electron vector and axial vector couplings to the Z0 are extracted from a combined analysis of the polarized Bhabha scattering data and the left-right asymmetry previously published by this collaboration.

1 data table match query

No description provided.


A Measurement of the b anti-b forward backward asymmetry using the semileptonic decay into muons

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adami, F. ; et al.
Phys.Lett.B 276 (1992) 536-546, 1992.
Inspire Record 322498 DOI 10.17182/hepdata.29264

The forward-backward asymmetry of bottom quarks is measured with statistics of approximately 80 000 hadronic Z 0 decays produced in e + e − collisions at a centre of mass energy of √ s ≈ M z . The tagging of b quark events has been performed using the semileptonic decay channel b→X+ μ . Because the asymmetry depends on the weak coupling, this leads to a precise measurement of the electroweak mixing angle sin 2 θ w . The experimental result is A FB b = 0.115±0.043(stat.)±0.013(syst.). After correcting the value for the B 0 B 0 mixing this becomes A FB b =0.161±0.060(stat.)±0.021(syst.) corresponding to sin 2 θ W MS =0.221±0.011( stat. )±0.004( syst. ) .

2 data tables match query

Experimentally measured asymmetry.

Asymmetry corrected for mixing using mixing parameter 0.143 +- 0.023.


Determination of A(b)(FB) using jet charge measurements in Z decays.

The ALEPH collaboration Barate, R. ; Buskulic, D. ; Decamp, D. ; et al.
Phys.Lett.B 426 (1998) 217-230, 1998.
Inspire Record 468671 DOI 10.17182/hepdata.49559

An improved measurement of the forward-backward asymmetry in Z →b b ̄ decays is presented, based on a sample of 4.1 million hadronic Z decays collected by ALEPH between 1991 and 1995. Data are analysed as a function of polar angle of the event axis and b purity. The event tagging efficiency and mean b -jet hemisphere charge are measured directly from data. From the measured forward-backward jet charge asymmetry, the b quark asymmetry at s =m Z is determined to be: A b FB =0.1017±0.0038(stat.)±0.0032(syst.). In the context of the Standard Model this corresponds to a value of the effective weak mixing angle of sin 2 θ W eff =0.23109±0.00096.

2 data tables match query

Only statistical errors are given for sqrt(s) = 89.43 and 92.97 GeV.

The combination of the data on and off peak of Z-boson.