Related papers: On the squared spin-orbit correction to the positr…
High-order perturbative corrections to positronium decays and hyperfine splitting are briefly reviewed. Theoretical predictions are compared to the most recent experimental data. Perspectives of future calculations are discussed.
The order $\alpha^4 R_{\infty}$ corrections to positronium $P$ levels are found. The calculation is reduced to the ordinary perturbation theory for the nonrelativistic Schr\"odinger equation. The perturbation operators have the Breit-type…
Precise numerical calculation of radiofrequency intervals between hyperfine sublevels of the $(37,35)$ state of the antiprotonic helium-4 atom is presented. Theoretical consideration includes the QED corrections of order $m\alpha^6$ to the…
Improved values of hyperfine coefficients related to the electronic spin-orbit and electron-nucleus spin-spin tensor interactions in the HD$^+$ molecular ion are obtained through numerical calculation of relativistic corrections at the…
We consider higher-order corrections to hyperfine coefficients related to the spin-orbit and spin-spin tensor interactions in hydrogen molecular ions. The $m\alpha^7 \ln(\alpha)$-order radiative correction is derived in the NRQED framework.…
Positronium annihilation amplitudes that are computed by assuming a factorization approximation with on-shell intermediate leptons, do not exhibit good analytical behavior. We propose an ansatz which allows to include binding energy…
An "ultrafine" splitting in positronium between the $L=1$ spin-singlet state and the spin-average of the spin-triplet states is shown to arise only at order $\alpha^6$. The QED prediction for $n=2$ states is…
It is well-known that atoms can change their shape when subject to external electromagnetic fields. Analogous phenomenon is expected for particles, which are much smaller in size with the corresponding shape change much harder to observe.…
Recently we derived the next-to-next-to-leading order post-Newtonian Hamiltonians at spin-orbit and spin(1)-spin(2) level for a binary system of compact objects. In this talk the derivation of them will be shortly outlined at an…
This is the second of a series of papers on the radiative corrections of order $\alpha^2 (Z\alpha)$, $\alpha (Z\alpha )^2$, and various logarithmic terms of order $\alpha^4$, to the hyperfine structure of the muonium ground state. This…
We report on progress in calculation of the spin-orbit interaction for the HD$^+$ molecular ion. This interaction is currently the largest source of theoretical uncertainty in determination of the hyperfine structure of rovibrational…
Motivated by recent theoretical and experimental controversy, we present a theoretical study to clarify the orbital symmetry of the ground state of vanadium spinel oxides AV$_2$O$_4$ (A=Zn, Mg, Cd). The study is based on an effective…
The leading nonperturbative effects to the fine and hyperfine splitting were calculated some time ago. Recently, they have been used in order to obtain realistic numerical results for the lower levels in bottomonium systems. We point out…
We have completed theoretical predictions for positronium energy levels through order alpha^6 m by the calculation of the spin independent, radiative recoil correction. This contribution is significant and amounts to 10.64 MHz for the 1S…
We provide analytical results for the $O(\alpha_s)$ corrections to the polar angle dependence of the longitudinal spin-spin correlation asymmetry in $e^+e^-\to q\bar q$. For top quark pair production the $O(\alpha_s)$ corrections to the…
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.
We obtain for the first time all quadratic-in-spin interactions in spinning binaries at the third subleading order in post-Newtonian (PN) gravity, and provide their observable binding energies and their gauge-invariant relations to the…
We compute the N$^3$LO gravitational quadratic-in-spin interactions at $G^4$ in the post-Newtonian (PN) expansion via the effective field theory (EFT) of gravitating spinning objects for the first time. This result contributes at the $5$PN…
We consider eigenmodes of a ring resonator made of a circular dielectric waveguide. Taking into account the polarization corrections, which are responsible for the interaction of polarization and orbital properties of electromagnetic waves…
To leading order in displacement size, the scattering of electrons in a Cu-O plane from O displacements perpendicular to that plane is due to spin-orbit coupling. This scattering is investigated with the following results: (1) As a…