Top-quark forward-backward asymmetry in Randall-Sundrum models beyond the leading order
We calculate the tt¯tt¯ 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...
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| Hauptverfasser: | , |
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| Dokumenttyp: | Article (Journal) |
| Sprache: | Englisch |
| Veröffentlicht: |
10 November 2010
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| In: |
Journal of high energy physics
Year: 2010, Heft: 11 |
| ISSN: | 1029-8479 |
| DOI: | 10.1007/JHEP11(2010)039 |
| Online-Zugang: | Verlag, kostenfrei, Volltext: http://dx.doi.org/10.1007/JHEP11(2010)039 Verlag, kostenfrei, Volltext: https://link.springer.com/article/10.1007/JHEP11(2010)039 
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| Verfasserangaben: | M. Bauer, F. Goertz, U. Haisch, T. Pfoh and S. Westhoff |
| Zusammenfassung: | We calculate the tt¯tt¯ 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. |
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| Beschreibung: | Gesehen am 21.11.2017 |
| Beschreibung: | Online Resource |
| ISSN: | 1029-8479 |
| DOI: | 10.1007/JHEP11(2010)039 |