Abstract.
The most precise measurement of the weak mixing angle \(\sin^2 \theta_{\mathrm{eff}}^l\) at LEP is from the forward-backward asymmetry \(e^ + e^- \rightarrow b \overline{b}\) at the Z-pole. In this note the QED and electroweak radiative corrections to obtain the pole asymmetry from the measured asymmetry for b- and c-quarks have been calculated using ZFITTER, which has been amended to allow a consistent treatment of partial two-loop corrections for the b-quark final asymmetries. A total correction of \(\delta A_{\mathrm{FB}}^{{b}} = 0.0019 \pm 0.0002\) and \(\delta A_{\mathrm{FB}}^{{c}} = 0.0064 \pm 0.0001\) has been found, where the remaining theoretical uncertainty is much too small to explain the apparent discrepancy between \(\sin^2 \theta_{\mathrm{eff}}^l\) obtained from A FB b and from the left-right asymmetry at SLD.
Similar content being viewed by others
References
The LEP collaborations, A Combination of Preliminary Electroweak Measurements and Constraints on the Standard Model, CERN-EP/2003-091, hep-ex/0312023
LEP Heavy Flavour Working Group Collaboration, D. Abbaneo et al. , Eur. Phys. J. C 4, 185 (1998)
The LEP Heavy Flavour Group, Final input parameters for the LEP/SLD heavy flavour analyses, LEPHF/01-01, http:/www.cern.chLEPEWWG/heavylephf0101.ps.gz
D.Y. Bardin et al. , Comput. Phys. Com. 133, 229 (2001)
ALEPH, DELPHI, L3, OPAL Collaboration, Nucl. Instrum. Methods A 378, 101 (1996)
A. Freitas, W. Hollik, W. Walter, G. Weiglein, Phys. Lett. B 495, 338 (2000) [Erratum B 570, 260 (2003)]; Nucl. Phys. B 632, 189 (2002) [Erratum B 666, 305 (2003)]; M. Awramik, M. Czakon, Phys. Lett. B 568, 48 (2003)
M. Awramik, M. Czakon, Phys. Rev. Lett. 89, 241801 (2002); A. Onishchenko, O. Veretin, Phys. Lett. B 551, 111 (2003); M. Awramik, M. Czakon, A. Onishchenko, O. Veretin, Phys. Rev. D 68, 053004 (2003); M. Awramik, M. Czakon, A. Freitas, G. Weiglein, Phys. Rev. D 69, 053006 (2004)
M. Awramik, M. Czakon, A. Freitas, G. Weiglein, Phys. Rev. Lett. 93, 201805 (2004) [hep-ph/0407317]; see also Nucl. Phys. Proc. Suppl. 135, 119 (2004) [hep-ph/0408207]; hep-ph/0409142
G. Degrassi, P. Gambino, A. Vicini, Phys. Lett. B 383, 219 (1996); G. Degrassi, P. Gambino, A. Sirlin, Phys. Lett. B 394, 188 (1997); G. Degrassi, P. Gambino, Nucl. Phys. B 567, 3 (2000)
M. Faisst, J.H. Kühn, T. Seidensticker, O. Veretin, Nucl. Phys. B 665, 649 (2003)
The LEP EWWG and SLD Heavy Flavour and Electroweak Groups, D. Abbaneo et al. , hep-ex/0112021
/afs/cern.ch/user/b/bardindy/public/ZF6\_41.
G. Montagna et al. , Comput. Phys. Com. 117, 278 (1999)
D.Y. Bardin, M. Grünewald, G. Passarino, hep-ph/9902452
Author information
Authors and Affiliations
Corresponding author
Additional information
Received: 1 December 2004, Published online: 9 March 2005
Rights and permissions
About this article
Cite this article
Freitas, A., Mönig, K. Corrections to quark asymmetries at LEP. Eur. Phys. J. C 40, 493–496 (2005). https://doi.org/10.1140/epjc/s2005-02164-6
Issue Date:
DOI: https://doi.org/10.1140/epjc/s2005-02164-6