Related papers: Hard Three-Loop Corrections to Hyperfine Splitting…
The ground-state hyperfine splitting values of high-Z boronlike ions are calculated. Calculation of the interelectronic-interaction contribution is based on a combination of the 1/Z perturbation theory and the large-scale…
We analyze the octet baryon masses and the pion/kaon--nucleon $\sigma$--terms in the framework of heavy baryon chiral perturbation theory. We include {\it all} terms up-to-and-including quadratic order in the light quark masses, $m_q$. We…
The contribution of the weak interaction to the hyperfine splitting of the ground state of muonium is investigated. The amplitudes of the one- and two-quantum exchange determined by the Z and W bosons are calculated. One-loop corrections in…
(New version with some expanded discussion; figures and minor typos corrected.) We have calculated the contribution proportional to the fifth power of the pion mass in the chiral expansion of the nucleon mass in two flavour HBCPT. Only one…
There is renewed interest in studies of muonic atoms, which may provide detailed information on nuclear structure. A major limiting factor in the interpretation of measurements is the nuclear polarization contribution. We propose a method…
We review the current status of perturbative corrections in QCD at four loops for scattering processes with space- and time-like kinematics at colliders, with specific focus on deep-inelastic scattering and electron-positron annihilation.…
We present an analytical calculation of the complete $\alpha^6$ correction to energies of $nP$-levels of two-body systems consisting of the spin-$0$ or $1/2$ extended-size particles with arbitrary masses and magnetic moments. The obtained…
We compute corrections to the hard thermal (or dense) loop photon polarization tensor associated to a small mass $m$ of the fermions of an electromagnetic plasma at high temperature $T$ (or chemical potential $\mu$). To this aim we use the…
In this paper we consider two-loop two-, three- and four-point diagrams with elliptic structure in the case of two different masses $m$ and $M$. The latter diagrams generally arise within NRQCD matching procedures and are relevant for…
The hyperfine mass splittings of baryons in large $N$ QCD are proved to be proportional to ${\bf J}^2$. Hyperfine mass splittings are first allowed at order $1/N$ in the $1/N$ expansion.
We calculate the complete order $1/N$ corrections to baryon masses in the rigid rotator approach to the 3-flavor Skyrme model.
The logarithmically enhanced alpha^3 ln(1/alpha) corrections to the para- and orthopositronium decay widths are calculated in the framework of dimensionally regularized nonrelativistic quantum electrodynamics.In the case of parapositronium,…
Terms contributing to the hyperfine structure of the muonium ground state at the level of few tenths of kHz have been evaluated. The $\alpha^2 (Z\alpha)$ radiative correction has been calculated numerically to the precision of 0.02 kHz.…
We present an analytical calculation of the two-loop QCD corrections to the electromagnetic form factor of heavy quarks. The two-loop contributions to the form factor are reduced to linear combinations of master integrals, which are…
Recently it has been realized that the production and decay processes of charginos, neutralinos, and sleptons receive corrections which grow like log m_squark for large m_squark. In this paper we calculate the chargino pair production cross…
Two-loop electroweak corrections to the electron, muon, and tau lepton anomalous magnetic moments have been computed recently. Effects of hadronic contributions to the photon propagator in two-loop QED corrections have also been reanalysed.…
The screened QED corrections of the first orders in \alpha and 1/Z to the g factor and the hyperfine splitting of lithiumlike ions are evaluated within ab initio quantum electrodynamical approach. The complete gauge-invariant set of the…
Recently, $O(\alpha^3)$ corrections to the muon decay rate and $O(\alpha_s^3)$ to heavy quark decays have been determined by Fael, Sch\"onwald, and Steinhauser. This is the first such perturbative improvement of these important quantities…
I evaluate the largest three-loop corrections to the mass of the lightest Higgs scalar boson in the Minimal Supersymmetric Standard Model in a mass-independent renormalization scheme, using effective field theory and renormalization group…
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…