相关论文: 1S-3S cw spectroscopy of hydrogen/deuterium atom
Positronium and muonium, as purely leptonic atoms without internal structure, provide ideal systems for high-precision tests of quantum electrodynamics (QED) and measurements of fundamental constants. However, the high velocities of these…
We propose a new spectroscopic method for measuring weak transitions in cold and trapped atoms, which exploits the long interaction times and tight confinement offered by dark optical traps together with an electron shelving technique to…
We report the detection of Deuterium absorption at redshift 2.525659 towards Q1243+3047. We describe improved methods to estimate the Deuterium to Hydrogen abundance ratio (D/H) in absorption systems, including improved modeling of the…
We describe experiments with spin-polarized atomic hydrogen gas adsorbed on liquid $^{4}$He surface. The surface gas density is increased locally by thermal compression up to $5.5\times10^{12}$ cm$^{-2}$ at 110 mK. This corresponds to the…
The discrepancy between the measured Lamb shift in muonic hydrogen and expectations from electron-proton scattering and regular hydrogen spectroscopy has become known as the proton radius puzzle, whose most "mundane" resolution requires a…
The energy dependence of the photon-proton total cross section was determined from positron-proton scattering data collected with the ZEUS detector at HERA at three values of the center-of-mass energy, W, of the \gamma p system in the range…
Differential cross-section measurements are presented for the production of a $W$ boson in association with a photon. The analysis is performed using proton--proton collision data collected by the ATLAS experiment at $\sqrt{s}= 13$ TeV,…
In this work, we report on the atom probe tomography analysis of two metallic hydrides formed by pressurized charging using an ex situ hydrogen charging cell, in the pressure range of 200-500 kPa (2-5 bar). Specifically we report on the…
A triple-GEM detector with two-dimensional readout is developed. The detector provides high position resolution for powder diffraction experiments at synchrotron radiation. Spatial resolution of the detector is measured in the lab using a…
We present a measurement of the deuterium to hydrogen ratio in a quasar absorption system at redshift z = 3.57 towards QSO 1937-1009. We use a two component fit, with redshifts determined from unsaturated metal lines, to fit the hydrogen…
In the present paper, we consider nonresonant corrections to $ 2s-ns/nd $ transition frequencies in hydrogen for the experiments based on two-photon spectroscopy. A detailed study of angular correlations of quantum interference effects…
The ``neutron lifetime puzzle'' arises from the discrepancy between neutron lifetime measurements obtained using the beam method, which measures decay products, and the bottle method, which measures the disappearance of neutrons. To resolve…
The spectrum of the $z_{\rm em} = 2.63$ quasar Q1009+2956 has been observed extensively on the Keck telescope. The Lyman limit absorption system $z_{\rm abs} = 2.504$ was previously used to measure D/H by Burles & Tytler using a spectrum…
The Kagome material $A{\mathrm{V}}_3{\mathrm{Sb}}_5$ ($A$ = K, Rb, Cs) with geometry frustration hosts non-trivial topological electronic structures, electronic nematicity, charge density wave (CDW) and superconductivity, providing an ideal…
We study the two-photon process for the transitions ns --> 1s and nd --> 1s in hydrogen up to large n. For n<=20 we provide simple analytic fitting formulae to describe the non-resonant part of the two-photon emission profiles. Combining…
We report the first detection outside of the solar system of the lowest pure rotational J=1-0 transition of the HD molecule at 112 microns. The detection was made toward the Orion Bar using the Fabry-Perot of the Long Wavelength…
The two-photon transition $5S-5P-5D$ in rubidium vapor is investigated by detecting the fluorescence from the $6P_{3/2}$ state when the atomic system is excited by the combined action of a cw diode laser and a train of ultrashort pulses.…
We've performed precise measurements of electron scattering on molecular hydrogen and deuterium by using the "Troitsk nu-mass" setup. Electrons were generated by the electron gun with an energy line width better than 0.3 eV. The electron…
We study energy spectrum for hydrogen atom with deformed Heisenberg algebra leading to minimal length. We develop correct perturbation theory free of divergences. It gives a possibility to calculate analytically in the 3D case the…
Results of inclusive measurements of inelastic electron and positron scattering from unpolarized protons and deuterons at the HERMES experiment are presented. The structure functions $F_2^p$ and $F_2^d$ are determined using a…