Related papers: Deep inside the pion. Reconciling QCD theory with …
We develop the analysis of diphoton exclusive photoproduction in the kinematics where a collinear QCD factorization framework applies, namely nearly forward large invariant mass diphoton production. We work at the leading twist level and at…
We calculate next-to-leading-order (NLO) correction to the pion electromagnetic form factor at leading twist in the $k_T$ factorization theorem. Partons off-shell by $k_T^2$ are considered in both quark diagrams and effective diagrams for…
An NLO QCD analysis of the final HERMES data on pion multiplicities is presented and a new set of pion fragmentation functions is extracted from the best fit to the data. We have studied the so-called [x,z] and [Q^2,z] presentations of…
A theoretical analysis has been performed of the HERMES semi-inclusive deep inelastic data on the difference between $\pi^{+}$ and $\pi^{-}$ multiplicities. It turns out that the application of a standard perturbative QCD analysis, using,…
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 investigate electroproduction of pion pairs on the nucleon in the framework of QCD factorization for hard exclusive processes. We extend previous analyses by taking the hard-scattering coefficients at next-to-leading order in $\alpha_s$.…
Two-parton correlations in the pion are investigated in terms of double parton distribution functions. A Poincar\'e covariant Light-Front framework has been adopted. As non perturbative input, the pion wave function obtained within the…
We prove new soft pion theorem for the near threshold pion production by a hard electromagnetic probe. This theorem relates various near threshold pion production amplitudes to the nucleon distribution amplitudes. The new soft pion theorem…
High precision measurements of the form factors of proton, pion, and kaon for timelike momentum transfers of |Q^2|=s=14.2 and 17.4 GeV^2 have been made. Data taken with the CLEO-c detector at sqrt(s)=3.772 GeV and 4.170 GeV, with integrated…
In these proceedings, we extend the discussion of the pion PDF obtained by NLO QCD analysis in the Fant\^omas4QCD framework. Our pion analysis uses a state-of-the-art statistical methodology that accounts for the epistemic uncertainty.…
Recent results from phenomenological studies of the CLAS data on 2$\pi$ electroproduction off proton are presented. The analysis is focused on extracting of N $\to$ $N^{*}$ electromagnetic transition amplitudes from the full data set on…
We present an investigation of the electromagnetic pion form factor, $F_\pi(Q^2)$, at small values of the four-momentum transfer $Q^2$ ($\lesssim 0.25$ GeV$^2$), based on the gauge configurations generated by European Twisted Mass…
We study the anomalous electromagnetic pion form factor $F_{\pi^0\gamma^*\gamma^*}$ with a set of holographic models. By comparing with the measured value of the linear slope, some of these models can be ruled out. From the remaining models…
The dynamical model of pion electroproduction has been extended to investigate the weak pion production reactions. The predicted cross sections of neutrino-induced pion production reactions are in good agreement with the existing data. We…
The pion distribution amplitude (DA) can be related to the fundamental QCD Green's functions as a function of the quark self-energy and the quark-pion vertex, which in turn are associated with the pion wave function through the…
Exclusive two-pion production near threshold in the collision of a highly virtual photon with a real one offers a new possibility to unravel the partonic content of hadrons. We explain the dynamics of this regime, i.e. the separation of the…
We examine the contribution of the pion cloud to the electromagnetic $N \rightarrow \Delta$ transition form factors within a relativistic hybrid constituent-quark model. In this model baryons consist not only of the $3q$ valence component,…
We update the leading order in $\alpha_s$ QCD amplitude for deep exclusive neutrino and antineutrino production of a light meson on an unpolarized nucleon. The factorization theorems of the collinear QCD approach allow us to write the…
This is an English translation of my 1977 Russian preprint. It contains the first explicit definition of the pion distribution amplitude (DA), the expression for the pion form factor asymptotics in terms of the pion DA, and formulates the…
A numerical investigation of time-separated charge overlap measurements is carried out for the pion in the context of lattice QCD using smeared Wilson fermions. The evolution of the charge distribution function is examined and the expected…