Related papers: Comparison with model-independent and dependent an…
Measurements of SIDIS multiplicities for $\pi^+$ and $\pi^-$ from proton and deuteron targets are reported on a grid of hadron kinematic variables $z$, $P_{T}$, and $\phi^{*}$ for leptonic kinematic variables in the range $0.3<x<0.6$ and…
Energy dependence of space-time parameters of pion emission region at freeze-out is studied for collisions of various ions and for all experimentally available energies. The using of femtoscopic radii scaled on the averaged radius of…
The Lamb shift measurement and theory are now both a dynamically developing field and we give a review of the current data. Critical comparison of theory and experiment can be done using a value of the proton charge radius and we pay…
We report on the measurement of freeze-out radii for pairs of identical-charge pions measured in Pb--Pb collisions at $\sqrt{s_{\rm NN}}=2.76$ TeV as a function of collision centrality and the average transverse momentum of the pair $k_{\rm…
This is a review of progress in hadron structure physics from lattice QCD. Recent results on the structure of the nucleon and the pion in terms of (transition) form factors, moments of distribution amplitudes and (generalized) parton…
We report a first principle lattice calculation of the pion electric polarizability $\alpha_\pi$ at the physical pion mass. First, we derive the master formula, which relates the pion polarizabilities with the position space hadronic…
A knowledge of the radial distributions of quarks inside hadrons could lead to a better understanding of the QCD description of these hadrons and possibly suggest forms for phenomenological models. As a step in this direction, in an earlier…
Bose-Einstein correlations of both neutral and like-sign charged pion pairs are measured in a sample of 2 million hadronic Z decays collected with the L3 detector at LEP. The analysis is performed in the four-momentum difference range 300…
In light of recent experimental progress in determining the pressure and shear distributions in the proton, these quantities are calculated in a model with confined quarks supplemented by the pion field required by chiral symmetry. The…
We extend our study of the pion scalar radius in two-flavour lattice QCD to include two additional lattice spacings as well as lighter pion masses, enabling us to perform a combined chiral and continuum extrapolation. We find discretisation…
We extend recently developed methods used for determining the electromagnetic charge radius and $a_\mu^{\pi\pi}$ to obtain a determination of the electromagnetic form factor of the pion, $F_\pi^V(t)$, in several significant kinematical…
The work is devoted to a consideration of the different determinations of the proton charge radius. It is demonstrated that the results from the elastic electron-proton scattering have to be of a higher uncertainty. A review of the hydrogen…
We have determined the proton and the neutron charge radii from a global analysis of the proton and the neutron elastic form factors, after first performing a flavor decomposition of these form factors under charge symmetry in the light…
We discuss aspects of a covariant QCD modeling of meson physics by illustrating applications to several coupling constants and form factors. In particular, we cover the $\rho\pi\pi$ and $\pi^0 \gamma \gamma$ interactions, the $\rho$…
Recent data from high statistics experiments that have measured the modulus of the pion electromagnetic form factor from threshold to relatively high energies are used as input in a suitable mathematical framework of analytic continuation…
I discuss recent progress made in calculating electromagnetic corrections in the framework of the effective field theory of QCD. In the case of elastic pion-pion scattering, strong interaction predictions have been worked out to two loop…
In hadronic Z decays, we compare Bose-Einstein correlations in \Pgpz pairs with those in identical charged pion pairs. We also measure Bose-Einstein correlations in triplets of identical charged pions. From the first study, the source…
Using a holographic dual model of QCD, we compute the pion electromagnetic form factor F_pi(Q^2) in the spacelike momentum transfer region, as well as pion couplings to vector mesons g_rho^(n) pi pi. Spontaneous and explicit chiral symmetry…
We study a model-independent parameterization of the vector pion form factor that arises from the constraints of analyticity and unitarity. Our description should be suitable up to sqrt(s) ~ 1.2 GeV and allows a model-independent…
The standard definition of the electromagnetic radius of a charged particle (in particular the proton) is ambiguous once electromagnetic corrections are considered. We argue that a natural definition can be given within an effective field…