相关论文: Detection of the Direct Hyperfine Transition of Po…
The hyperfine structure of the ground states in a number of positronium hydrides (TPs, DPs, ${}^{1}$HPs) and MuPs ($\mu^{+} e^{-}_2 e^{+}$) is determined with the use of highly accurate variational wave functions. We also evaluate the…
We discuss positronium decays with emphasis on tests of fundamental symmetries and the constraints from measurements of other precision observables involving electrons and photons.
Optical precision experiments are a powerful tool to explore hidden sectors of a variety of standard-model extensions with potentially tiny couplings to photons. An important example is given by extensions involving an extra light U(1)…
In polarizable materials, electronic charge carriers interact with the surrounding ions, leading to quasiparticle behaviour. The resulting polarons play a central role in many materials properties including electrical transport, optical…
We propose a method for sensitive parallel detection of low-frequency electromagnetic fields based on the fine structure interactions in paramagnetic polar molecules. Compared to the recently implemented scheme employing ultracold $^{87}$Rb…
The possibility of channeling the low-energy relativistic positrons around separate crystallographic axes with coaxial symmetry of negative ions in some types of crystals is shown. The process of annihilation of positrons with electrons of…
Quasi-forbidden electronic transitions in atoms and quasi-degenerate vibronic transitions in molecules serve as powerful probes of hypothetical temporal variations of fundamental constants. Computation of the sensitivity of a transition to…
We perform precision microwave spectroscopy--aided by Stark deceleration--to reveal the low magnetic field behavior of OH in its ^2\Pi_{3/2} ro-vibronic ground state, identifying two field-insensitive hyperfine transitions suitable as…
Molecular vibrational transitions are prime candidates for model-independent searches for variation of the proton-to-electron mass ratio. Searches for present-day variation achieve highest sensitivity with deep molecular potentials. We…
We revisit the $m \alpha^6 (m/M)$ order corrections to the hyperfine splitting in the H$_2^+$ ion, and find a hitherto unrecognized second-order relativistic contribution associated with the vibrational motion of the nuclei. Inclusion of…
Radiative electron-proton scattering is studied in peripheral kinematics, where the scattered electron and photon move close to the direction of the initial electron. Even in the case of unpolarized initial electron the photon may have a…
Direct photons are a powerful probe to study the properties of the unique matter created in ultrarelativistic heavy-ion collisions. They carry information on the various stages of a heavy-ion collision. At different transverse momenta (pT),…
In contrast to other atomic systems, in true muonium ($\mu^+\mu^-$) the leading-order $Z$ boson corrections to the hyperfine splitting are shown to be experimentally accessible in the near future. This contribution ($-109$ MHz) constitutes…
The contribution of the proton polarizability to the ground state hyperfine splitting in the hydrogen atom is evaluated on the basis of isobar model and evolution equations for the parton distributions. The contributions of the Born terms,…
In the last twenty years, the theory of hyperfine splitting in muonium developed without any experimental input. Finally, this situation is changing and a new experiment on measuring hyperfine splitting in muonium is now in progress at…
The recent observation and measurement of the decay $Z_c(3900) \to \rho \eta_c$ provides the data on the relative strength of the pion and $\rho$ coupling in the corresponding transitions between exotic resonances and pure heavy quarkonium.…
Fast beam collinear laser spectroscopy is the established method to investigate nuclear ground state properties such as the spin, the electromagnetic moments, and the charge radius of exotic nuclei. These are extracted with high precision…
The order - \alpha radiative corrections to the differential decay rate of polarized orthopositronium are obtained. Their influences on the three photons coincidence rate as a function of positronium polarization is considered.
The cross sections for the production of hadrons in quasi-real photon-photon collisions in proton-proton and heavy ion interactions are compared with the corresponding cross sections for central diffraction and for photon-pomeron…
We report the observation of the hyperfine spectrum of the weak P(63)4-4 line of the B-X electronic transition of molecular iodine 127I2 near 652.4 nm, using frequency-modulated saturated absorption spectroscopy. Through the precise…