相关论文: Hyperfine splitting in positronium to ${\cal O}(\a…
A detailed presentation is given of the analytic calculation of the single-photon annihilation contributions to the positronium ground state hyperfine splitting to order $m_e\alpha^6$ in the framework of non-relativistic effective theories.…
The single photon annihilation contributions for the positronium ground state hyperfine splitting are calculated analytically to order $m_e\alpha^6$ using NRQED. Based on intuitive physical arguments the same result can also be determined…
The logarithmically enhanced alpha^7 ln(1/alpha) contribution to the hyperfine splitting of the positronium ground-state energy levels is calculated in the framework of dimensionally regularized nonrelativistic quantum electrodynamics. The…
Positronium spectroscopy (n=1 hyperfine splitting, n=2 fine structure, and the 1S-2S interval) has reached a precision of order 1 MHz. Vigorous ongoing efforts to improve the experimental results motivate the calculation of the positronium…
We have calculated all contributions to the energy levels of parapositronium at order $m \alpha^7$ coming from vacuum polarization corrections to processes involving virtual annihilation to two photons. This work is motivated by ongoing…
We have calculated the contribution to the positronium hyperfine splitting at order $m \alpha^7$ of the light-by-light scattering process in the exchange of two photons between the electron and positron. Our result is $\Delta E =…
Recent and ongoing experimental work on the positronium spectrum motivates new efforts to calculate positronium energy levels at the level of three loop corrections. We have obtained results for one set of such corrections involving…
We present an analytic calculation of the m*alpha^6 recoil corrections to the hyperfine splitting (HFS) of the ground state energy levels in positronium. We find \Delta E_{\rm rec} = m alpha^6 (-1/6 ln(alpha) + 331/432 -ln(2)/4 - 17…
The two-photon-annihilation contribution to the true muonium hyperfine splitting arising from $e$ and $\tau$ loops is obtained analytically at order $m_\mu\alpha^6$. The contribution to the hyperfine splitting is $-2.031092873…
Ongoing improvements in the measurement of positronium transition intervals motivate the calculation of the $O(m \alpha^7)$ corrections to these intervals. In this work we focus on corrections to the spin-singlet parapositronium energies…
We investigate one-photon annihilation of the electron-positron pair in the field of a central, very heavy and positively charged atomic nucleus. The explicit formula for the annihilation rate of this process $\Gamma^{(b)}_{1 \gamma}$ is…
The complete contribution to the muonium hyperfine splitting of relative order alpha^3(m_e/m_mu)ln(alpha) is calculated. The result amounts to 0.013 kHZ, much smaller than suggested by a previous estimate, and leads to a 2-sigma shift of…
We compute O(alpha^3 ln alpha) relative corrections to the ground state hyperfine splitting of a QED two body bound state with different masses of constituents. The general result is then applied to muonium and positronium. In particular, a…
We consider hard three-loop nonlogarithmic corrections of order $m\alpha^7$ to hyperfine splitting in positronium. All these contributions are generated by the graphs with photon and/or electron loop radiative insertions in the two-photon…
We present a calculation of the O(m alpha^7 ln(alpha)^2) corrections to positronium energy levels. The result is used to estimate the current uncertainty in theoretical predictions of the positronium spectrum.
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…
This work attempts to present a complete theory of the $\mu$H hyperfine splitting, including all contributions above 1 ppm. Quantum electrodynamic and recoil corrections are calculated directly, while the proton structure correction is…
Interference between different energy eigenstates in a quantum system results in an oscillation with a frequency which is proportional to the difference in energy between the states. Such an oscillation is observable in polarized…
We compute the next-to-leading, O(m alpha^5), contribution to the hyperfine splitting in positronium within the framework of NRQED. When applied to the ground state, our calculation reproduces known results, providing a further test of…
We present an analytic calculation of the O(m alpha^6) recoil and radiative recoil corrections to energy levels of positronium nS states and their hyperfine splitting. A complete analytic formula valid to O(m alpha^6) is given for the…