Related papers: The Pion Form Factor
This paper reviews the experimental status of heavy baryons. It covers the aspec ts of production, spectroscopy and decay presenting recent results obtained in this fi eld. It closes with an outlook on further work on and with heavy baryons…
A model is developed for electromagnetic form factor of the pion. One-loop corrections are included in the linear sigma-model. The rho-meson contribution is added in an extended VMD model. The form factor, calculated without fitting…
It is shown that the recent determination of the various proton charge extensions is compatible with Standard Model expectations.
Pion transition form factor for the process $\gamma*\gamma*\to \pi^0$ at space-like values of photon momenta is calculated within the effective quark-meson model with the interaction induced by instanton exchange. The leading and…
Recently published data on the Sachs electric form factor by the PRad collaboration (Nature {\bf 575}, 147-151) are analyzed to investigate their consistency with the known proton charge radius from muonic and electronic hydrogen…
The nucleon elastic form factors are generally interpreted as a mapping of the charge and magnetic current distributions of the proton and neutron. New high Q^2 measurements have opened up fundamental questions about G_ep that remain to be…
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…
The nucleon electromagnetic form factors have been studied in the past extensively from unpolarized electron scattering experiments. With the development in polarized beam, recoil polarimetry, and polarized target technologies, polarization…
Recent measurement of the $\gamma\gamma^\ast$ form factor of the neutral pion in the high $Q^2$ region disagrees with {\em a priori} predictions of QCD-based calculations. We comment on existing explanations, and analyze a possibility that…
We propose a dispersive representation of the charged pion vector form factor that is consistent with chiral symmetry and fulfills the constraints imposed by analyticity and unitarity. Unknown parameters are fitted to the very precise data…
Nucleon electromagnetic form factors are fundamental quantities related to the charge and magnetization distributions inside the nucleon. Understanding the nucleon electromagnetic structure in terms of the underlying quark and gluon degrees…
The theoretical and experimental status of the isovector axial-vector current form factors G_A(q^2) and G_P(q^2) of the nucleon is reviewed. We also describe a new calculation of these form factors in manifestly Lorentz-invariant chiral…
The structure of hadronic form factors at high energies and their deviations from perturbative quantum chromodynamics provide insight on nonperturbative dynamics. Using an approach that is consistent with dispersion relations, we construct…
We study the pion form factor in a broad range of spacelike momentum transfers within the local-duality version of QCD sum rules. We make use of the recently calculated two-loop double spectral density of the $<AVA>$ correlator including…
In this paper I review a number of recent results in the field of exotic atoms. Recent experiments or ongoing experiments with muonic, pionic and antiprotonic hydrogen, as well as recent measurement of the pion mass are described. These…
The vector form factor of the decay $\pi^{+} \rightarrow \gamma + e^{+} + \nu_e$ is calculated by the method for the pseudovector pion-nucleon system. The non-perturbative term is taken into account by using the parameter for the…
Simple dynamics, few available decay channels, and extremely well controlled radiative and loop corrections, make pion and muon decays a sensitive means for testing the underlying symmetries, the universality of weak fermion couplings, as…
The status of theoretical calculations of the strange quark vector current form factors of the nucleon is reviewed.
The charged and neutral kaon form factors are calculated as a phenomenological application of the QCD Dyson-Schwinger equations. The results are compared with the pion form factor calculated in the same framework and yield…
Results of the Spectral Quark Model for the gravitational, electromagnetic, and transition form factors of the pion are discussed. In this model both the parton distribution amplitude and the parton distribution function are flat, in…