1305.7386 (Cen Zhang et al.)

Top-quark decay into Higgs and a light quark at NLO in QCD    [PDF]

Cen Zhang, Fabio Maltoni

Neutral flavor changing transitions are hugely suppressed in the Standard Model and therefore they are very sensitive to new physics. We consider the decay rate of t->u_i h where u_i=u,c using an effective field theory approach. We perform the calculation at NLO in QCD including the relevant dimension-six operators. We find that at NLO the contribution from the flavor-changing chromo-magnetic operator is as important as the standard QCD correction to the flavor-changing Yukawa coupling. In addition to improving the accuracy of the theoretical predictions, the NLO calculation provides information on the operator mixing and their behaviour under the renormalization group.

View original: http://arxiv.org/abs/1305.7386