Related papers: Zemach and magnetic radius of the proton from the …
We present a dispersion theoretical analysis of recent date from electron-proton scattering. This allows for a high-precision extraction of the electric and magnetic radius of the proton, $r_E = (0.839\pm 0.002{}^{+0.002}_{-0.003})$~fm and…
We have analyzed the proton form factor data by using a number of phenomenological parameterizations (models) and extracting the proton electric and magnetic radii. To this end we performed a global fit to all available form factor data,…
In 2010 the proton charge radius was extracted for the first time from muonic hydrogen, a bound state of a muon and a proton. The value obtained was five standard deviations away from the regular hydrogen extraction. Taken at face value,…
Proton charge radius is calculated from the electromagnetic form factor of proton parameterized by the dispersion relation. The calculated charge radius is a little larger than that obtained by the Lamb shift of the $\mu$ mesic atom. As the…
We investigate the influence of the spatial extent of the proton magnetization and charge densities on the 2S hyperfine splitting in muonic hydrogen. The use of a non-perturbative relativistic Dirac approach leads to corrections of 15% to…
The recent values of the proton charge radius obtained by means of muonic-hydrogen laser spectroscopy are about $4\%$ different from the electron scattering data. It has been suggested that the proton radius is actually measured in…
The ongoing experimental efforts to measure the hyperfine transition in muonic hydrogen prompt an accurate evaluation of the proton-structure effects. At the leading order in $\alpha$, which is $O(\alpha^5)$ in the hyperfine splitting…
Modern electron scattering experiments have determined the proton electric form factor, G_{Ep}(Q^2), to high precision. We utilize this data, represented by the different form factor parametrizations, to compute the third Zemach moment of…
The proton radius has been measured in electron-proton scattering experiments and laser based spectroscopy of muonic hydrogen. The latter method is based on the precise calculations for the atomic energy levels in the approximation of…
The proton radius puzzle remains a key challenge in modern physics, highlighting both the precision and limitations of current experimental and theoretical approaches. Recent studies, such as those by Xiong et al. and Bezginov et al., have…
Using a procedure based on interpolation via continued fractions supplemented by statistical sampling, we analyse proton magnetic form factor data obtained via electron+proton scattering on $Q^2 \in [0.027,0.55]\,$GeV$^2$ with the goal of…
High-precision measurements of the proton radius from laser spectroscopy of muonic hydrogen demonstrated up to six standard deviations smaller values than obtained from electron-proton scattering and hydrogen spectroscopy. The status of…
Recently, the charge radius of the proton was extracted for the first time from muonic hydrogen. The value obtained is five standard deviations away from similar measurements of regular hydrogen. This talk discusses work done in…
The relationship between the electric form factors for the proton in the rest frame and in the Breit momentum frame is used to provide a value for the difference in the mean squared charge radius of the proton evaluated in the two frames.…
We show that in previous analyses of electron-proton scattering, the uncertainties in the statistical procedure to extract the proton charge radius are underestimated. Using a fit function based on a conformal mapping, we can describe the…
We report on a comprehensive reinterpretation of the existing cross-section data for elastic electron-proton scattering obtained by the initial-state radiation technique, resulting in a significantly improved accuracy of the extracted…
The FAMU experiment at RIKEN-RAL is a muonic atom experiment with the aim to determine the Zemach radius of the proton by measuring the 1s hyperfine splitting in muonic hydrogen. The activity of the FAMU Collaboration in the years 2015-2023…
We reanalyze electron-proton scattering data in the momentum transfer region $Q^2 < 1\ GeV^2$, which were used to determine proton electric radius, with main focus on the Mainz experiment (Bernauer et al., 2010). We examine dependence of…
New precise results of a measurement of the elastic electron-proton scattering cross section performed at the Mainz Microtron MAMI are presented. About 1400 cross sections were measured with negative four-momentum transfers squared up to…
A measurement of the Lamb shift of 49,881.88(76) GHz in muonic hydrogen in conjunction with theoretical estimates of the proton structure effects was recently used to deduce an accurate but rather small radius of the proton. Such an…