Related papers: Experiments towards resolving the proton charge ra…
We review recent experiments on HD$^+$ spectroscopy. The reduced proton-deuteron mass to electron mass ratio, $\mu_{pd}/m_e$, is inferred from the comparison of theory and experiment. Theoretical issues related to the calculations of the…
Improved measurements of the proton's structure are now possible thanks to significant technical advances that allow us to probe the proton with polarized photons. These measurements have shown that the proton is not as simple as previously…
In proton-proton collisions there is a smooth transition between the regime of double parton scattering, initiated by two pairs of partons at a large relative distance, and the regime where a single parton splits into a parton pair in one…
To date the magnetic radius of the proton has been determined only by means of electron-proton scattering, which is not free of controversies. Any existing atomic determinations are irrelevant because they are strongly model-dependent. We…
The proton size has been found, with a $6\,\sigma$ statistical significance, to be larger by 4% when it is measured relatively to the electron than to the muon [Pohl2010,Antognini2013]. We solve this proton radius puzzle by accounting for…
Modern experiments with heavy ion-leptons collisions open the possibility to measure the deviation of cross section of small angles electron(positron)-ion elastic scattering from the Rutherford formula due to multiple virtual photons…
We determine the charge radius of the proton by analyzing the published low momentum transfer electron-proton scattering data from Mainz. We note that polynomial expansions of the form factor converge for momentum transfers squared below…
The status of the solar neutrino problem is reviewed. Attempts to explain the observed deficit and spectral distortion, both by astrophysical and particle physics methods, are described. It is argued that the comparison of all experiments…
Lattice calculations for hadrons are now entering the domain of resonances and scattering, necessitating a better understanding of the observed discrete energy spectrum. This is a reviewing survey about recent lattice QCD results, with some…
We discuss recent suggestions on the resolution of the proton radius puzzle put forward in [1,2] and discovery of a nonperturbative quantum-electrodynamic contribution of order $(\alpha/\pi)^5$ to lepton anomalous magnetic moments announced…
We propose an experiment for an accurate measurement of the proton radius. A key feature of our proposal is an iron-free magnetic spectrometer. Projected systematics uncertainties will allow a 1% level accuracy for the $r_p$ value.
We explore the possibility that a new interaction between muons and protons is responsible for the discrepancy between the CODATA value of the proton radius and the value deduced from the measurement of the Lamb shift in muonic hydrogen. We…
Recent ineleastic electron-proton scattering experiments have led to rather accurate values for the N->Delta transition quadrupole moment Q(N->Delta).The experimental results imply a prolate (cigar-shaped) intrinsic deformation of the…
Measurements of the difference between the squared charge radii of the helion ($^3$He nucleus) and the $\alpha$-particle ($^4$He nucleus) have been characterized by longstanding tensions, recently spotlighted in the 3.6 $\sigma$ discrepancy…
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…
We analyze the elastic scattering of protons on a 4n system. This was used as part of the detection technique of a recent experiment [1] to search for the 4n (tetraneutron) as a bound particle. We show that it is unlikely that this process…
The precision of experimental data and analysis techniques is a key feature of any discovery attempt. A striking example is the proton radius puzzle where the accuracy of the spectroscopy of muonic atoms challenges traditional electron…
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…
We present a novel method for extracting the proton radius from elastic electron-proton ($ep$) scattering data. The approach is based on interpolation via continued fractions augmented by statistical sampling and avoids any assumptions on…
We perform a new analysis of electron-proton scattering data to determine the proton electric and magnetic radii, enforcing model-independent constraints from form factor analyticity. A wide-ranging study of possible systematic effects is…