相关论文: Massive form factors at $\mathcal{O}(\alpha_s^3)$
We compute the three-loop non-singlet corrections to the photon-quark form factors taking into account the full dependence on the virtuality of the photon and the quark mass. We combine the method of differential equations in an effective…
We consider Quantum Chromodynamics with external vector, axial-vector, scalar and pseudo-scalar currents and compute three-loop corrections to the corresponding vertex function taking into account massive quarks. We consider all non-singlet…
Heavy quark form factors are calculated at $\beta_0 \alpha_s \sim 1$ to all orders in $\alpha_s$ at the first order in $1/\beta_0$. The $n_f^2 \alpha_s^3$ terms in the recent results [arXiv:1611.07535] for the vector form factors are…
The quarkonic contributions to the three-loop heavy-quark form factors for vector, axial-vector, scalar and pseudoscalar currents are described by closed form difference equations for the expansion coefficients in the limit of small…
In this contribution we provide further details to the recent calculation of QCD corrections to massive three-loop form factors presented in Ref. [1].
We compute three-loop corrections to the singlet form factors for massive quarks using a semi-analytic method which provides precise results over the whole kinematic range. Particular emphasis is put on the anomaly contribution originating…
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 present the calculation of the $K_{l3}$ form factors with $N_f = 2 + 1$ nonperturbatively $O(a)$-improved Wilson quark action and Iwasaki gauge action at the physical point on a large volume of (10.9 fm)$^3$ at one lattice spacing of $a…
We compute three-loop corrections of $\mathcal{O}(\alpha_{s}^3)$ to form factors with one massive and one massless quark coupling to an external vector, axialvector, scalar, pseudoscalar, or tensor current. We obtain analytic results for…
We compute the three-loop QCD corrections to the massive quark form factors with external vector, axial-vector, scalar and pseudo-scalar currents. All corrections with closed loops of massless fermions are included. The non-fermionic part…
In this work we present the computation of so-called oriented event-shape distributions for massive quarks up to $\mathcal{O}(\alpha_s)$, along with the total oriented cross section in which one does not look at the geometric properties of…
Recent progress in the calculation of multi-loop, multi-scale diagrams is reviewed. Expansion techniques combined with new developments in Computer algebra allow to evaluate the R ratio for massive quarks up to order $\alpha_s^2$ and,…
We compute the O(1/M,m_s) heavy quark and SU(3) corrections to B_s -> D_s e nu form factors. In the limit of vanishing light quark mass, B_s -> D_s e nu form factors are given in terms of the the B -> D e nu form factors, the leading order…
The infinite mass effective theory, when a heavy quark mass tends to infinity, and Chiral perturbation theory at the quark level, based on the extended Nambu -- Jona -- Lasinio model with linear realization of chiral $U(3)\times U(3)$…
We consider the three-loop mixed strong-electroweak (${\mathcal{O}}(\alpha \alpha_s^2)$) corrections to the quark form factor. We compute the master integrals which are appearing in the Feynman diagrams containing a single massive boson in…
The form factors for the $K_{\ell 3}$ semileptonic decay are computed to order $O(p^4)$ in generalized chiral perturbation theory. The main difference with the standard $O(p^4)$ expressions consists in contributions quadratic in quark…
We calculate the vector form factor in K \to \pi l \nu semileptonic decays at zero momentum transfer f_+(0) from numerical simulations of two-flavor QCD on the lattice. Our simulations are carried out on 16^3 \times 32 at a lattice spacing…
We compute the three-loop QCD corrections to the massive quark-anti-quark-photon form factors $F_1$ and $F_2$ in the large-$N_c$ limit. The analytic results are expressed in terms of Goncharov polylogarithms. This allows for a…
We analyse various $U(1)_{EM}$ form factors of mesons at strong coupling in an $\mathcal{N}=2$ flavored version of $\mathcal{N}=4$ $SYM$ which becomes conformal in the UV. The quark mass breaks the conformal symmetry in the IR and generates…
We consider the virtual corrections to Higgs boson pair production at next-to-next-to-leading order, in the large top quark mass limit. We compute five expansion terms for the box-type form factors and eight expansion terms for the triangle…