Speaker
Description
We present a comprehensive study of the electromagnetic form factors (EMFFs) of the pion and kaon, as well as the generalized parton distributions (GPDs) of the pion, using lattice QCD. For the form factors, we compute the pion and kaon EMFFs at high momentum transfers, $-t$, up to 10 and 28 GeV$^2$, respectively, achieving good agreement with experimental results up to $-t$ $\lesssim$ 4 GeV$^2$ and providing benchmarks for forthcoming experiments. We also test the QCD collinear factorization framework, relating form factors to meson distribution amplitudes, at next-to-next-to-leading order (NNLO) in perturbation theory. Additionally, we report a lattice calculation of $x$-dependent pion GPDs at zero skewness with multiple values of momentum transfers. We determine the Lorentz-invariant amplitudes of the quasi-GPD matrix elements for both symmetric and asymmetric momenta transfers with similar values and show the equivalence of both frames. Then, focusing on the asymmetric frame, we utilize a hybrid scheme to renormalize the quasi-GPD matrix elements obtained from the lattice calculations. After the Fourier transform, the quasi-GPDs are then matched to the light-cone GPDs within the framework of large momentum effective theory with improved matching, including the next-to-next-to-leading order perturbative corrections, and leading renormalon and renormalization group resummations. We also present the 3-dimensional image of the pion in impact-parameter space through the Fourier transform of the momentum transfer $-t$.
