Related papers: Third order Coulomb correction to ttbar threshold …
We compute the third-order corrections to the heavy quarkonium spectrum and production/annihilation rates due to the leading renormalization group running of the static potential. The previously known complete ${\cal O}(m_q\alpha_s^5)$…
We present the QCD corrections of order $\alpha_s^3$ to the decay rate of $b \to u \ell \bar \nu_\ell$, with $\ell = e,\mu$, originating from diagrams with closed fermion loops and neglecting the mass of the up quark. Our calculation relies…
I present improved predictions for the total hadronic cross section of stop-antistop production at hadron colliders including next-to-next-to-leading-order threshold corrections and approximated Coulomb corrections. The results are based on…
Using the variational method and supersymmetric quantum mechanic we calculate in a approximate way eigenvalues, eigenfunctions and wave functions at origin of Cornell potential. We compare results with numerical solutions for heavy…
Recently the full O(alpha_S^5 m, alpha_S^5 m log(alpha_S)) correction to the heavy quarkonium 1S energy level has been computed (except the a_3-term in the QCD potential). We point out that the full correction (including the…
The differential and total cross sections for the d+p->3He+eta reaction have been measured in a high precision high statistics COSY-ANKE experiment near threshold using a continuous beam energy ramp up to an excess energy Q of 11.3 MeV with…
We present an analytical description of top-antitop pair production near the threshold in $e^+e^-$ annihilation and $\g\g$ collisions. A set of basic observables considered includes the total cross sections, forward-backward asymmetry and…
The possible importance of threshold effects in heavy quarkonium spectroscopy is discussed. The starting point is the calculation of the spectrum of heavy quarkonium-like states with self-energy/threshold corrections. Two different…
We discuss corrections from the elastic limit (partonic threshold) in hadronic hard-scattering cross sections. We show why these corrections can be large at all orders in perturbation theory, and describe their resummation to arbitrary…
In this paper we revisit the one-dimensional tunnelling problem. We consider different approximations for the transmission through the Coulomb barrier in heavy ion collisions at near-barrier energies. First, we discuss approximations of the…
The influence of the Coulomb distortion for quasi-elastic (e,e') scattering on highly charged nuclei is investigated in distorted wave Born approximation for electrons. The Dirac equation is solved numerically in order to obtain exact…
Second order ${\cal O}(\alpha_s^2)$ corrections to the heavy quark production cross-section due to massless quarks and coloured scalars are calculated for all energies above threshold. Based on the method introduced in this letter also the…
We review in some detail the QCD corrections to the measurement of the forward-backward charge asymmetry of heavy quarks in the $\mathrm{e^+e^-\rightarrow Q\overline{Q}(g)}$ process at the Z pole. We show that the size of these corrections…
We investigate top quark pair production near the threshold where the pair invariant mass $M_{t\bar{t}}$ approaches $2m_t$, which provides sensitive observables to extract the top quark mass $m_t$. Using the effective field theory methods,…
The qualitative difference in the use of retarded and Feynman amplitudes as demonstrated in nucl-th/0101024 had been wrongly considered in this comment. The concept of the breakdown of crossing symmetry is not effective in the case…
The process e^+ e^- to t \bar t H is considered in the kinematic end point region where the Higgs energy is close to its maximal energy. In perturbative QCD, using the loop expansion, the amplitudes are plagued by Coulomb singularities that…
We study the resummation of large logarithmic perturbative corrections to the partonic cross sections relevant for the process pp->gamma X at high transverse momentum of the photon.These corrections arise near the threshold for the partonic…
The self-energy screening correction is evaluated in a model in which the effect of the screening electron is represented as a first-order perturbation of the self energy by an effective potential. The effective potential is the Coulomb…
The next-to-leading order (NLO) P-wave Coulomb Green function contributes at third-order to top-pair production in e+ e- collisions near threshold. In this paper we compute the NLO P-wave Green function in dimensional regularization, as…
Toponium production at future hadron colliders is investigated. Perturbative QCD corrections to the production cross section for gluon fusion are calculated as well as the contributions from gluon-quark and quark-antiquark collisions to the…