Related papers: Proton-electron mass ratio from HD$^+$ revisited
Molecular transitions recently discovered at redshift z_abs=2.059 toward the bright background quasar J2123-0050 are analysed to limit cosmological variation in the proton-to-electron mass ratio, mu=m_p/m_e. Observed with the Keck…
In an effort to resolve the discrepancy between two measurements of the fundamental constant mu, the proton to electron mass ratio, at early times in the universe we reanalyze the same data used in the earlier studies. Our analysis of the…
We show that the value of the proton mass depends on each bound state of muonic or electronic hydrogen atom. The charged particle bound to the proton produces magnetic field inside the proton. This makes a change to the amount of chiral…
Intensive theoretical and experimental efforts over the past decade have aimed at explaining the discrepancy between data for the proton electric to magnetic form factor ratio, $G_{E}/G_{M}$, obtained separately from cross section and…
The Standard Model of particle physics assumes that the so-called fundamental constants are universal and unchanging. Absorption lines arising in molecular clouds along quasar sightlines offer a precise test for variations in the…
Exotic cosmologies predict variability of the fundamental physical constants over the cosmic time. Using the VLT/UVES high resolution spectra of the quasar Q0347-3819 and unblended electronic - vibrational - rotational lines of the H2…
The existence and stability of atoms rely on the fact that neutrons are more massive than protons. The measured mass difference is only 0.14\% of the average of the two masses. A slightly smaller or larger value would have led to a…
We present an analysis of the proton mass radius by studying the $t$-dependence of the differential cross sections of the vector meson photoproductions near the thresholds. At low energy, the photoproduction of a quarkonium off the proton…
We present analytical expressions for direct evaluation of $\ell$-mixing rate coefficients in proton-excited hydrogen atom collisions and describe a software package for efficient numerical evaluation of the collisional rate coefficients.…
We present the largest 3D Particle-in-Cell shearing-box simulations of turbulence driven by the magnetorotational instability, for the first time employing the realistic proton-to-electron mass ratio. We investigate the energy partition…
At the LHC, two experiments - ATLAS and TOTEM - measure the total proton-proton cross section. Unfortunately, a significant discrepancy, persisting at different collision energies, is observed between the values reported by the two groups.…
The ratio between the proton and electron masses is shown to be close to the ratio between the strong and electromagnetic interaction coupling constants at Extremely Low Energy (ELE). Based on the experimental data, this relation has been…
Exploiting the isobar model, kaon photo- and electroproduction on the proton in the resonance region comes under scrutiny. An upgrade of our previous model, comprising higher-spin nucleon and hyperon exchanges in the consistent formalism,…
The largest hyperfine interaction coefficients in the hydrogen molecular ion HD$^+$, i.e. the electron-proton and electron-deuteron spin-spin scalar interactions, are calculated with estimated uncertainties slightly below 1~ppm. The…
An overview is presented of the H$_2$ quasar absorption method to search for a possible variation of the proton--electron mass ratio $\mu=m_p/m_e$ on a cosmological time scale. Details of the analysis of astronomical spectra, obtained with…
The rovibrational transition frequencies of molecular hydrogen ions (MHI) can be accurately computed using ab initio nonrelativistic quantum electrodynamics. A subset of the fundamental constants are required input. We analyze how, once…
A previously proposed geometric definition of mass in terms of energy, in a geometrical unified theory, is used to obtain a numerical expression for a ratio of masses of geometrical excitations. The resultant geometric ratio is…
It is shown that the account for the proton charge form factor in the Coulomb corrections to the electron-proton scattering cross section noticeably diminishes the difference between the value of the proton charge radius $r_{\mathrm{E}}$,…
Atomic hydrogen energy levels calculated to high precision are required to assist experimental researchers working on spectroscopy in the pursuit of testing quantum electrodynamics (QED) and probing for physics beyond the Standard Model.…
The ratio of the proton's elastic electromagnetic form factors was obtained by measuring the transverse and longitudinal polarizations of recoiling protons from the elastic scattering of polarized electrons with unpolarized protons. The…