Forward-backward asymmetry of top quark pair production

Journal Article · Tue Jun 01 00:00:00 EDT 2010 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.81.114004· OSTI ID:21407950

Qinghong, Cao ^[1]; McKeen, David; Rosner, Jonathan L ^[2]; Shaughnessy, Gabe ^[1]; Wagner, Carlos E. M. ^[1]

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1. HEP Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)
2. Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637 (United States)

We adopt a Markov chain Monte Carlo method to examine various new physics models which can generate the forward-backward asymmetry in top quark pair production observed at the Tevatron by the CDF Collaboration. We study the following new physics models: (1) exotic gluon G{sup '}, (2) extra Z{sup '} boson with flavor-conserving interaction, (3) extra Z{sup '} with flavor-violating u-t-Z{sup '} interaction, (4) extra W{sup '} with flavor-violating d-t-W{sup '} interaction, and (5) extra scalars S and S{sup {+-}}with flavor-violating u-t-S and d-t-S{sup {+-}}interactions. After combining the forward-backward asymmetry with the measurement of the top pair production cross section and the tt invariant mass distribution at the Tevatron, we find that an axial vector exotic gluon G{sup '} of mass about 1 TeV or 2 TeV or a W{sup '} of mass about 2TeV offer an improvement over the standard model. The other models considered do not fit the data significantly better than the standard model. We also emphasize a few points that have been long ignored in the literature for new physics searches: (1) heavy resonance width effects, (2) renormalization scale dependence, and (3) next-to-leading order corrections to the tt invariant mass spectrum. We argue that these three effects are crucial to test or exclude new physics effects in the top quark pair asymmetry.

• OSTI ID: 21407950
• Journal Information: Physical Review. D, Particles Fields, Vol. 81, Issue 11; Other Information: DOI: 10.1103/PhysRevD.81.114004; (c) 2010 The American Physical Society; ISSN 0556-2821
• Country of Publication: United States
• Language: English

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