Related papers: Third order Coulomb correction to ttbar threshold …
We compute the third-order correction to the S-wave quarkonium wave functions |\psi_n(0)|^2 at the origin from non-Coulomb potentials in the effective non-relativistic Lagrangian. Together with previous results on the Coulomb correction and…
The precise knowledge of the onset of the cross section $\sigma(e^+e^- \to \tau^+\tau^-)$ at the threshold is necessary for improving the accuracy of determination of the $\tau$ mass from the threshold measurements. The QED radiative…
We provide a detailed account of the methods and calculations for the third-order corrections to the S-wave Green function from heavy-quark potentials other than the Coulomb potential. The results of this paper are relevant to the…
We obtain analytic expressions for the third-order corrections due to the strong interaction Coulomb potential to the S-wave Green function, energy levels and wave functions at the origin for arbitrary principal quantum number n. Together…
The QED Coulomb correction is one of the most important corrections to the e+ e- --> W+ W- total cross section near threshold. We calculate these corrections through second order, and discuss the implications for extracting M_W from a…
Recent developments in the treatment of a system of heavy quarks close to their production threshold are discussed. Particular emphasis is put on the next-to-next-to-next-to-leading order (N$^3$LO) corrections to the energy levels and the…
We report new results of the NNNLO correction to the S-wave quarkonium wave-functions at the origin, which also provide an estimate of the resonance cross section in t-tbar threshold production at the ILC.
We calculate the cross section of the process e^+e^- \to t\bar t near threshold by resumming Coulomb-like terms with next-to-next-to-leading (NNLO) accuracy. The nonrelativistic Green function formalism and the method of ``direct matching''…
In this talk I review the calculation of the third order corrections to the heavy quarkonium spectrum in the nonrelativistic effective theory framework and its application to the phenomenology of top quark threshold production.
Starting from an asymptotically correct three-body Coulomb wave-function, we determine the effect of Coulomb final state interaction on the three-particle Bose-Einstein correlation function of similarly charged particles. We numerically…
Recently full O(alpha_s^2, alpha_s*beta, beta^2) corrections to the threshold total cross section for e+e- to ttbar have been calculated, and the reported corrections turned out to be unexpectedly large. We study how to reduce theoretical…
The Coulomb corrections to the helicity amplitudes of high-energy photon splitting are examined. The consideration is based on the amplitudes obtained exactly in the parameter Z\alpha within the quasiclassical approach valid for small…
We re-evaluate the electromagnetic corrections to eta --> 3 pi decays at next-to-leading order in the chiral expansion, arguing that effects of order e^2(m_u-m_d) disregarded so far are not negligible compared to other contributions of…
We re-evaluate the electromagnetic corrections to eta --> 3 pi decays at next-to-leading order in the chiral expansion, arguing that effects of order e^2(m_d-m_u) disregarded so far are not negligible compared to other contributions of…
We investigate $e^+ e^- \to t\bar t$ by taking into account wave function distortion effects in the near-threshold region and interpolating the correction factor to the high-energy perturbative QCD region. The strong color attraction…
We consider top-anti-top production near threshold in $e^+ e^-$ collisions, resumming Coulomb-enhanced corrections at next-to-next-to-leading order (NNLO). We also sum potentially large logarithms of the small top quark velocity at the…
Next-to-next-to-leading contributions to the cross section sigma(e+e- -> tau+tau-) at energies close to threshold are analysed, taking into account the known non-relativistic effects and O(alpha^2) corrections. The numerical changes with…
The differential cross section of high-energy electroproduction in the electric field of heavy atoms is derived. The result is obtained with the exact account of the atomic field by means of the quasiclassical approximation to the wave…
We study the physical origins of the $O(alpha_{s})$ and $O(alpha_{s}^{2})$ corrections to the $bar{c}-s$ current in the decay $b -> c bar{c} s$ in the threshold region $delta=(M_{b}-2m_{c})/2M_{b} << 1$. We obtain the corrections which are…
The differential and partially integrated cross sections are considered for bremsstrahlung from high-energy electrons in atomic field with the exact account of this field. The consideration exploits the quasiclassical electron Green's…