Journal of High Energy Physics

, 2010:39

Top-quark forward-backward asymmetry in Randall-Sundrum models beyond the leading order


  • M. Bauer
    • Institut für Physik (THEP)Johannes Gutenberg-Universität
  • F. Goertz
    • Institut für Physik (THEP)Johannes Gutenberg-Universität
    • Institut für Physik (THEP)Johannes Gutenberg-Universität
  • T. Pfoh
    • Institut für Physik (THEP)Johannes Gutenberg-Universität
  • S. Westhoff
    • Institut für Physik (THEP)Johannes Gutenberg-Universität

DOI: 10.1007/JHEP11(2010)039

Cite this article as:
Bauer, M., Goertz, F., Haisch, U. et al. J. High Energ. Phys. (2010) 2010: 39. doi:10.1007/JHEP11(2010)039


We calculate the \( t\overline t \) forward-backward asymmetry, AtFB, in Randall-Sundrum (RS) models taking into account the dominant next-to-leading order (NLO) corrections in QCD. At Born level we include the exchange of Kaluza-Klein (KK) gluons and photons, the Z boson and its KK excitations, as well as the Higgs boson, whereas beyond the leading order (LO) we consider the interference of tree-level KK-gluon exchange with one-loop QCD box diagrams and the corresponding bremsstrahlungs corrections. We find that the strong suppression of LO effects, that arises due to the elementary nature and the mostly vector-like couplings of light quarks, is lifted at NLO after paying the price of an additional factor of αs/(4π). In spite of this enhancement, the resulting RS corrections in AtFB remain marginal, leaving the predicted asymmetry SM-like. As our arguments are solely based on the smallness of the axial-vector couplings of light quarks to the strong sector, our findings are model-independent and apply to many scenarios of new physics that address the flavor problem via geometrical sequestering.


Phenomenology of Field Theories in Higher Dimensions

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© SISSA, Trieste, Italy 2010