I will present next-to-leading order QCD predictions for the process of top quark pair production in association with a b-jet pair at the LHC with center of mass energy of 13 TeV. In the calculation we concentrated on the di-leptonic decay channel of the top quark pair and we considered full off-shell effects. This study is particularly relevant for the measurements of the Higgs properties,...
In this talk I will discuss selected aspects of our calculation of the previously unknown NNLO QCD corrections to the $B_s - \bar{B}_s$ mixing process. These contributions are required to reduce the existing theory uncertainty on $\Delta \Gamma_{12}^s$, the flavor mixing parameter governing lifetime differences of neutral $B_s$ mesons.
We computed the tth fragmentation function at order O(yt2 αs). Real and virtual corrections have been computed by using modern loop computation techniques. In particular, we combined the unitary cut method with the differential equation approach. Moreover, we found a strategy for calculating the master integrals analytically, order by order in the dimensional regulator ε, in canonical basis.
The impact of the finite top-quark mass on the inclusive Higgs production cross section at higher perturbative orders has been an open question for almost three decades. I will report on the computation of this effect at NNLO QCD. This result eliminates one of the main theoretical uncertainties to inclusive Higgs production cross section at the LHC.
In this talk we present our recent calculation of order $\alpha_s^3$ corrections to the semi-leptonic $b\to c$ and the muon decays. The calculation has been performed in an expansion around the heavy-daughter limit $m_c \sim m_b$, but also shows decent convergence for $m_c=0$ from which the contribution to the muon decay can be extracted.
