Light Colored Scalar as Messenger of Up-Quark Flavor Dynamics in Grand Unified Theories

Understand

The measured forward-backward asymmetry in the t tbar production at the Tevatron might be explained by the additional exchange of a colored weak singlet scalar.

• Such state appears in some of the grand unified theories and its interactions with the up-quarks are purely antisymmetric in flavor space.
• We systematically investigate the resulting impact on charm and top quark physics.
• The constraints on the relevant Yukawa couplings come from the experimentally measured observables related to D0--D0bar oscillations, as well as di-jet and single top production measurements at the Tevatron.