Related papers: Proton polarizabilities: status, relevance, prospe…
We comment on the status and history of the proton charge radius determinations.
Compton scattering offers in principle an intriguing new window on nucleon structure. Existing experiments and future programs are discussed and the state of theoretical understanding of such measurements is explored.
We comment on the puzzling status of the proton magnetic radius determinations.
Electromagnetic polarizabilities describe the response of a system to the application of an external quasi-static electric or magnetic field. In this article experimental and theoretical work addressing the polarizabilities of the light…
We review the status of the proton charge radius puzzle. Emphasis is given to the various experiments initiated to resolve the conflict between the muonic hydrogen results and the results from scattering and regular hydrogen spectroscopy.
Spin polarizabilities of the nucleon are discussed in the framework of fixed-t and backward-angle dispersion relations, chiral perturbation theory, and the non-relativistic quark model. Calculations with the dispersion relations generally…
Recent attempts to detect the pion polarizability via analysis of $\gamma\gamma\rightarrow\pi\pi$ measurements are examined. The connection between calculations based on dispersion relations and on chiral perturbation theory is established…
A review of chiral perturbation theory and that of recent developments on the comparison of its predictions with experiment is presented. Some interesting topics with scope for further elaboration are touched upon.
Recent experimental results on the proton and neutron polarizabilities are examined from the point of view of backward dispersion relations. Results are found to be in reasonable agreement with the measured values. A rigorous relationship…
The "proton radius puzzle" remains unsolved since it was established in 2010. This paper summarizes the current state and gives an overview over upcoming experiments.
We calculate the nucleons' electromagnetic polarizabilities in heavy baryon chiral perturbation theory including all terms to order ${\cal O} (q^4)$. The chiral prediction of the electric polarizabilities for the neutron and the proton are…
The status of the proton radius puzzle (as of the date of the Confer- ence) is reviewed. The most likely potential theoretical and experimental explanations are discussed. Either the electronic hydrogen experiments were not sufficiently…
Polarized Compton scattering off the proton is studied within the framework of subtracted dispersion relations for photon energies up to 300 MeV. As a guideline for forthcoming experiments, we focus the attention on the role of the proton's…
We evaluate the electric and magnetic polarizabilities of charged pions in the framework of chiral perturbation theory at next-to-leading order. This requires a two-loop evaluation of the Compton amplitude near threshold. We estimate the…
A review of the present knowledge on polarized parton distributions is given. The effects of perturbative evolution on these distributions are discussed qualitatively and a comparison of various recent parametrizations is made.
The contribution of the proton polarizability to the hydrogen hyperfine splitting is evaluated on the basis of modern experimental and theoretical results on the proton polarized structure functions. The value of this correction is equal to…
We argue that the proton charge radius conundrum can be resolved by weakening the assumption of perturbative formulation of quantum electrodynamics within the proton
Recent attempts to determine the pion polarizability by dispersion relations yield values that disagree with the predictions of chiral perturbation theory. These dispersion relations are based on specific forms for the absorptive part of…
A survey is given on the present knowledge of the polarized parton distribution functions. We give an outlook for further developments desired both on the theoretical as well on the experimental side to complete the understanding of the…
Recent attempts to determine the pion polarizability by dispersion relations yield values that disagree with the predictions of chiral perturbation theory. These dispersion relations are based on specific forms for the absorptive part of…