Related papers: Specific three-loop contributions to $b\to s\gamma…
We compute the exact two-loop matching coefficients for the strong coupling constant alpha_s and the bottom-quark mass m_b within the Minimal Supersymmetric Standard Model (MSSM), taking into account O(alpha_s^2) contributions from…
We present an approach for computing the real parts of the nonleptonic B to DP and B to D-bar P (P=K,pi) decay amplitudes by using lattice QCD methods. While it remains very challenging to calculate the imaginary parts of these matrix…
We compute, for the first time, the absorptive part of the massless correlator of two quark scalar currents in five loops. As physical applications we consider the O(alpha_s^4) corrections to the decay rate of the Standard Model Higgs boson…
The calculation of the $O(N_f\alpha^2)$ corrections to muon decay is described. These are the 2-loop diagrams containing a massless fermion loop and they form an important gauge-invariant subclass. It is shown that all such diagrams can be…
General one-loop contributions to the decay amplitudes $H\rightarrow \nu_l\bar{\nu}_l\gamma$ are presented, considering all possible contributions of additional heavy vector gauge bosons, fermions, and charged (and also neutral) scalar…
This is a status report of the evaluation of the three-loop corrections to the static QCD potential of a heavy quark and an antiquark. The families of Feynman integrals that appear in the evaluation are described. To reduce any integral of…
Within the framework of the Standard Model Higgs extensions, including the Two-Higgs-Doublet Model with vector-like fermions and the Triplet-Higgs Model, we derive general one-loop contributions to the rare decay process $A \rightarrow Z…
We express the amplitudes for charmless three-body B decays in terms of diagrams. In addition, we show how to use Dalitz-plot analyses to obtain decay amplitudes which are symmetric or antisymmetric under the exchange of two of the…
We present analytic results for three-loop fermionic corrections to the heavy-light form factors in perturbative quantum chromodynamics. Specifically, we present all light quark contributions and contributions from two heavy quark loops. We…
We compute the two-loop term in the perturbation series for the quark-mass in the lattice Heavy Quark Effective Theory. This is an ingredient in the matching factor required to obtain the $b$-quark mass from lattice simulations of the HQET.…
We address the nonperturbative effects associated with soft charm quarks in inclusive B decays. Such corrections are allowed by the OPE, but have largely escaped attention so far. The related four-quark `double heavy' expectation values of…
We evaluate two-loop b -> s gamma matrix elements of all the four-quark operators containing no derivatives. Contrary to previous calculations, no expansion in the mass ratio mc/mb is performed, and all the possible Dirac and flavor…
We consider moments of the non-diagonal vector, axial-vector, scalar and pseudo-scalar current correlators involving two different massive quark flavours up to three-loop accuracy. Expansions around the limits where one mass is zero and the…
3-loop diagrams of the ladder-type, which emerge for local quarkonic twist-2 operator matrix elements, are computed directly for general values of the Mellin variable $N$ using Appell-function representations and applying modern summation…
We present the first analytic results of N$^3$LO QCD corrections to the top-quark decay width. We focus on the dominant leading color contribution, which includes light-quark loops. At NNLO, this dominant contribution accounts for 95% of…
A calculation of the leading isospin-breaking contributions to the B -> K^* gamma decay amplitudes based on the QCD factorization approach is presented. They arise at order Lambda/m_b in the heavy-quark expansion and are due to annihilation…
The calculation of massive three-loop QCD form factors using in particular the large moments method has been successfully applied to quarkonic contributions in [1]. We give a brief review of the different steps of the calculation and report…
We evaluate the complete four-loop anomalous dimension matrix that is necessary for determining the effective flavour-changing neutral current couplings qbar-q'-gamma and qbar-q'-g at the next-to-next-to-leading order in QCD. The resulting…
The paper deals with a next-to-leading order analysis of the radiative $B \to K^* \gamma$ decay. Working in a PQCD approach, we compute the correction to the essential form factor, coming from a single gluon exchange with the spectator. We…
The non-first-order-factorizable contributions (The terms 'first-order-factorizable contributions' and 'non-first-order-factorizable contributions' have been introduced and discussed in Refs. \cite{Behring:2023rlq,Ablinger:2023ahe}. They…