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arXiv · 0912.0972

Light colored scalars from grand unification and the forward-backward asymmetry in top quark pair production

Ilja Dorsner·Svjetlana Fajfer·Jernej F. Kamenik·Nejc Kosnik
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Abstract

The experimental results on the t bar t production cross section at the Tevatron are well described by the QCD contributions within the standard model, while the recent measurement of the forward-backward asymmetry cannot be accounted for within this framework. We consider light colored scalars appearing in a particular SU(5) GUT model within the 45-dimensional Higgs representation. A virtue of the model is that it connects the presence of a light colored SU(2) singlet (Delta_6) and a color octet weak doublet (Delta_1) with bounds on the proton lifetime, which constrain the parameter space of both scalars. We find that both the t bar t production cross section and the forward-backward asymmetry can be accommodated simultaneously within this model. The experimental results prefer a region for the mass of Delta_6 around 400 GeV, while Delta_1 is then constrained to have a mass around the TeV scale as well. We analyze possible experimental signatures and find that Delta_6 associated top production could be probed in the t bar t + jets final states at Tevatron and the LHC.

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Ilja Dorsner, Svjetlana Fajfer, Jernej F. Kamenik, Nejc Kosnik. 2009-12-07. Light colored scalars from grand unification and the forward-backward asymmetry in top quark pair production. https://doi.org/10.1103/physrevd.81.055009

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