Interplay of t→bW decay and Bd,s-B¯d,s mixing in Minimal Flavor Violating Models

Precise measurements of the top quark decay properties at hadron colliders offer interesting new possibilities of testing the standard model. At the same time, recent intriguing experimental results concerning CP violation in the Bd and Bs systems have stimulated many studies of physics beyond the standard model. We investigate anomalous tWdj interactions as a possible source of new effects in Bd,s-B¯d,s oscillations within a model independent approach based on the assumptions of Minimal Flavor Violation. After matching our effective operators onto the low-energy effective Lagrangian describing Bd,s meson mixing and evolving it down to the B-mass scale, we extract the preferred ranges of the anomalous tWdj interactions at the weak scale. These values are then compared to previously considered constraints coming from the rare radiative B→Xsγ decay. Finally, we reconsider the associated effects in the t→bW decays and find that the W helicity fractions FL,+ can deviate by as much as 15%, 30% from their standard model values, respectively. The deviations in FL in particular, can reach the level of expected precision measurements at the LHC.