Related papers: Note on the electromagnetic radius of proton
Recently a high-precision measurement of the Lamb shift in muonic hydrogen has been performed. An accurate value of the proton charge radius can be extracted from this datum with a high accuracy. To do that a sufficient accuracy should be…
The precise determination of the proton radius from recent elastic scattering electron-proton data is discussed. The necessary precision on the elastic cross section to discriminate among the values coming from atomic spectroscopy is…
New high precision polarization measurements of the proton elastic form factor ratio in the Q^2 range from 0.3 to 0.7 [GeV/c]^2 have been made. These elastic H(e,e'p) measurements were done in Jefferson Lab's Hall A using 80% longitudinally…
The electromagnetic form factors are crucial to our understanding of the proton internal structure, and thus provide a strong constraint of the distributions of the charge and magnetization current within the proton. We adopted the…
In this work, the cross-section of the reaction $\gamma p \rightarrow V(J/\psi,\psi(2S)) p$ from the production threshold to medium energy is studied and systematically analyzed within two gluon exchange model. The obtained numerical…
The "proton radius puzzle" was recently solved by reducing the four-standard deviation discrepancy between the results for electronic hydrogen ($H$) and muonic hydrogen ($\mu H$) atoms to $3.3$ value. The value of the root-mean-square…
Proton and neutron electric and magnetic form factors are the primary characteristics of their spatial structure and have been studied extensively over the past half-century. At large values of the momentum transfer $Q^2$ they should reveal…
We analyze the exclusive $\phi$-meson photoproduction on both hydrogen and deuterium targets based on the published data of CLAS, SAPHIR and LEPS collaborations. A dipole-form scalar gravitational form factor is applied to describe the…
It is suggested that proton elastic scattering on atomic electrons allows a precise measurement of the proton charge radius. Very small values of transferred momenta (up to four order of magnitude smaller than the ones presently available)…
The spatial distribution of charge and magnetization within the proton is encoded in the elastic form factors. These have been precisely measured in elastic electron scattering, and the combination of proton and neutron form factors allows…
The charge form factor of the pion is calculated in lattice QCD. The non-perturbatively improved Sheikholeslami-Wohlert action is used together with the $\mathcal{O}(a)$ improved vector current. Other choices for the current are examined.…
The measurement of the 2P^{F=2}_{3/2} to 2S^{F=1}_{1/2} transition in muonic hydrogen by Pohl et al. and subsequent analysis has led to the conclusion that the rms radius of the proton differs from the accepted (CODATA) value by…
The neutron is a cornerstone in our depiction of the visible universe. Despite the neutron zero-net electric charge, the asymmetric distribution of the positively- (up) and negatively-charged (down) quarks, a result of the complex…
We present a determination of the pion charge radius from high precision data on the pion vector form factor from both timelike and spacelike regions, using a novel formalism based on analyticity and unitarity. At low energies, instead of…
We discuss the recent data on the electric proton form factor, obtained at JLab, which show a spectacular deviation from the commonly assumed dipole behavior. We discuss the implication of these results on the deuteron structure and on the…
The charge radius of the proton can be determined using two different kinds of experiments: the spectroscopy technique, measuring the hyperfine structure of hydrogen atoms, and the scattering technique, deducing the radius from elastic…
We report the results of a new Rosenbluth measurement of the proton form factors at Q^2 values of 2.64, 3.20 and 4.10 GeV^2. Cross sections were determined by detecting the recoiling proton in contrast to previous measurements in which the…
The ratio of the electric and magnetic form factor of the proton, $\mu_p G_E^p/G_M^p$, has been measured for elastic electron-proton scattering with polarized beam and target up to four-momentum transfer squared, $Q^2=5.66$ (GeV/c)$^2$…
The structure of the proton remains a significant challenge within the field of Quantum Chromodynamics, with the origin of its spin and mass still lacking a satisfactory explanation. In this study, we utilize the gravitational form factor…
The Proton Radius Puzzle refers to the ~7{\sigma} discrepancy that exists between the proton charge radius determined from muonic hydrogen and that determined from electronic hydrogen spectroscopy and electron-proton scattering. One…