Related papers: Quark and gluon form factors to three loops
We calculate the form factors for weak decays of $B_{(s)}$ and $D_{(s)}$ mesons to light pseudoscalar and vector mesons within a relativistic dispersion approach based on the constituent quark picture. This approach gives the form factors…
The form factors for the hadron matrix element of the QCD energy-momentum tensor not only describe the coupling of the hadron with a graviton as the ``gravitational form factors'', but also serve as unique quantities for describing the…
The proton to $\Delta^+$ resonance transitional gravitational form factors are calculated to leading one-loop order using chiral perturbation theory in our recent work [1]. We take into account the leading electromagnetic and strong…
We compute the three-loop QCD corrections to the decoupling constant for $\alpha_s$ which relates the Minimal Supersymmetric Standard Model to Quantum Chromodynamics with five or six active flavours. The new results can be used to study the…
The electromagnetic form factors of nucleons are calculated using an AdS/QCD model by considering a Dirac field coupled to a vector field in the 5-dimensional AdS space. We also calculate a gravitational or energy-momentum form factor by…
After ten years from its discovery, the Higgs boson is still under unprecedented scrutiny. A huge theoretical effort has been invested in modelling Higgs boson production through gluon fusion, reaching $\text{N}^3\text{LO}$ predictions in…
We calculate the electromagnetic form factors of the nucleon up to fourth order in manifestly Lorentz-invariant chiral perturbation theory with vector mesons as explicit degrees of freedom. A systematic power counting for the renormalized…
The electromagnetic form factors of the nucleon, in the space-like region, are determined from three-point function Finite Energy QCD Sum Rules. The QCD calculation is performed to leading order in perturbation theory in the chiral limit,…
We discuss the recent derivation of the three-loop ${\cal O}(\alpha\alpha_s)$ contribution to the Higgs boson production cross section via gluon fusion arising from diagrams with light quarks, using an effective theory approach. We show…
A unified set of predictions for pion and kaon elastic electromagnetic and gravitational form factors is obtained using a symmetry-preserving truncation of each relevant quantum field equation. A key part of the study is a description of…
*REVISED VERSION* Two quark propagators with different analytic structure are employed in on and off mass-shell Bethe-Salpeter type equations for the pion and scalar diquark form-factors. One of the quark propagators has been calculated…
In the asymptotic limit $Q^2 \gg m^2$, the heavy quark form factors exhibit Sudakov behavior. We study the corresponding renormalization group equations of the heavy quark form factors which do not only govern the structure of infrared…
We analytically compute the four-loop QCD corrections for the colour structure $(d_F^{abcd})^2$ to the massless non-singlet quark form factor. The computation involves non-trivial non-planar integral families which have master integrals in…
We compute two-loop electroweak corrections to double Higgs boson production in gluon fusion mediated by light quarks in a fully analytical way. We determine a basis of master integrals satisfying canonical differential equations in…
The electromagnetic and axial form factors of the nucleon and its lowest positive parity excitations, the Delta(1232) and the N*(1440), are calculated with constituent-quark models that are specified by simple algebraic representations of…
In this article, we calculate the form factors and the coupling constant of the $g_{B^{\ast}_{s1}B^{\ast} K}$ vertex in the framework of the three-point QCD sum rules. Three point correlation functions responsible for the vertex are…
We present analytical and numerical results for the Dirac form factor of the quark-gluon vertex in the quark symmetric limit, where the incoming and outgoing quark momenta have the same magnitude but opposite sign. To accomplish this, we…
We present a calculation of the electric and magnetic form factors of ground-state octet and decuplet baryons including strange quarks. We work with a combination of Dyson-Schwinger equations for the quark propagator and covariant…
The nucleon axial form factor is a dominant contribution to errors in neutrino oscillation studies. Lattice QCD calculations can help control theory errors by providing first-principles information on nucleon form factors. In these…
We extend a local subtraction framework to three-loop QCD corrections for the production of multiple electroweak bosons in quark-antiquark annihilation. We derive two-loop Ward identities that ensure the factorisation of most collinear…