Related papers: The pion-photon transition form factor at two loop…
The holographic QCD prediction for the pion distribution amplitude (DA) $\phi_{hol}(u)$ is used to compute the pion spacelike electromagnetic form factor $F_{\pi}(Q^2)$ within the QCD light-cone sum rule method. In calculations the pion's…
In many years ago, Isgur and Llewellyn Smith addressed that PQCD is inapplicable to exclusive processes, such as the pion form factor.The main problem is that the asymptotic of PQCD is only about one fourth of the experimental value. We…
The electromagnetic form factor of the pion is calculated in the "point-form" of relativistic quantum mechanics using simple, phenomenological wave functions. It is found that the squared charge radius of the pion is predicted one order of…
We present the first full analytic evaluation of the scattering amplitude for the process $q {\bar q} \to Q {\bar Q}$ up-to two loops in Quantum Chromodynamics, for a massless $(q)$ and a massive $(Q)$ quark flavour. The interference terms…
We compute the two-loop helicity amplitudes for the production of three photons at hadron colliders in QCD at leading-color. Using the two-loop numerical unitarity method coupled with analytic reconstruction techniques, we obtain the…
We calculate the one-loop contributions to the difference \Delta_{\pi K} between the isoscalar on-shell pion-kaon scattering amplitude at the Cheng-Dashen point and the scalar form factor \Gamma_K (2M_\pi^2) in the framework of three flavor…
The $^{1}$H($e,e^\prime \pi^+$)n cross section was measured for a range of four-momentum transfer up to $Q^2$=3.91 GeV$^2$ at values of the invariant mass, $W$, above the resonance region. The $Q^2$-dependence of the longitudinal component…
We prove collinear factorization theorem for the process $\pi\gamma^*\to\pi$ at the twist-3 level in the covariant gauge by means of the Ward identity, concentrating on the two-parton case. It is shown that soft divergences cancel and…
The self-couplings of the electroweak gauge bosons are probed at hadron colliders through the production of a massive gauge boson and a photon. To extend the theoretical description of this type of final states towards…
We numerically compute the two-loop QCD corrections to $Z\gamma$ production at the LHC mediated by light- and heavy-quark box loops. The calculation employs the pipeline of refs. arXiv:2407.18051 and arXiv:2510.18801, which performs Monte…
We present the most accurate calculation for the pion and kaon electromagnetic form factors in the framework of perturbative QCD, where the power corrections up to twist-4 of the meson distribution amplitudes and the next-to-leading-order…
A critical set of two-loop QED corrections to the $g$ factor of hydrogenlike ions is calculated without expansion in the nuclear binding field. These corrections are due to the polarization of the external magnetic field by the quantum…
The pion form factor is calculated using quenched twisted mass QCD with beta=6.0 and maximal twisting angle omega=pi/2. Two pion masses and several values of momentum transfer are considered. The momentum averaging procedure of Frezzotti…
We present detailed numerical results for the pion space-like electromagnetic form factor obtained within a recently proposed model of the pion electromagnetic current in a confining light-front QCD-inspired model. The model incorporates…
We account for dynamical spin effects in the holographic light-front wavefunction of the pion in order to predict its mean charge radius, decay constant, spacelike electromagnetic form factor, twist-2 Distribution Amplitude and the…
The meson-photon transition form factors $\gamma\gamma^*\to P$ ($P$ stands for $\pi$, $\eta$ and $\eta'$) provide strong constraints on the distribution amplitudes of the pseudoscalar mesons. In this paper, these transition form factors are…
We comment on the results of a complete leading-twist next-to-leading order QCD analysis of the spacelike pion electromagnetic form factor at large-momentum transfer Q. For the asymptotic distribution amplitude, we have examined the…
We present the analytic calculation of the two-loop QCD corrections to the decay width of a Higgs boson into a photon and a $Z$ boson. The calculation is carried out using integration-by-parts identities for the reduction to master…
We study the non-forward matrix elements of twist-2 QCD light-ray operators and their representations in terms of skewed and double distributions, considering the pion as well as the nucleon. We point out the importance of explicitly…
We study the $\gamma\gamma\rightarrow M^{+}M^{-}(M=\pi, K)$ processes with the contributions from the two-particle twist-2 and twist-3 distribution amplitudes of pion and kaon mesons on BHL prescription in the standard hard-scattering…