Related papers: Bhabha Process at LEP - Theoretical Calculations
The size of non-perturbative corrections to event shape observables is predicted to fall like powers of the inverse centre of mass energy. These power corrections are investigated for different observables from $e^+e^-$-annihilation…
We consider quantum electrodynamics (QED) corrections to the fine splitting $E(2P_{3/2}) - E(2P_{1/2})$ in the Li atom. We derive complete formulas for the $m\,\alpha^6$ and $m\,\alpha^7\,\ln\alpha$ contributions and calculate them…
We present the electroweak one-loop corrections to the processes e+e- -> f bar-f, f = tau, c, b, t, at energies relevant for a future linear collider. The results of two independent calculations are compared and agreement is found at a…
Results of a calculation valid to all orders in the nuclear-strength parameter Z\alpha are presented for the two-loop Lamb shift, notably for the two-loop self-energy correction, for the ground and first excited states of ions with the…
The main result of this paper is a new exact algorithm computing the estimate given by the Least Trimmed Squares (LTS). The algorithm works under very weak assumptions. To prove that, we study the respective objective function using basic…
I discuss recent progress in the calculation of two-loop QCD corrections in the eikonal approximation. I present specific results for the UV structure of the corrections.
The complete list of definitions for quantities relevant in the analysis of SLD/LEP-1 results around the Z-resonance is given. The common set of conventions adopted by the programs TOPAZ0 and ZFITTER, following the recommendations of the…
A new method for absolute polarimetric calibration of large telescopes is presented. The proposed method is highly accurate and is based on the calibration of a small sub-aperture, which is then extended to the full system by means of…
We discuss some aspects of the theory of subelliptic estimates.
This paper explores the well known approximation approach to decide weak bisimilarity of Basic Parallel Processes. We look into how different refinement functions can be used to prove weak bisimilarity decidable for certain subclasses. We…
In the framework of the Littlest Higgs Model with T-parity (LHT), we study the contributions of the new particles to $Zb\bar{b}$ couplings at one-loop level. Based on these results, we further study the branching ratio $R_{b}$ and the…
The difference between a model forecast and actual observations is called forecast bias. This bias is due to either incomplete model assumptions and/or poorly known parameter values and initial/boundary conditions. In this paper we discuss…
This short summary reviews the recent progress in the computation of higher-order corrections to W+b W-antib production. In addition, new phenomenological studies reveal potential problems that may affect precision measurements at the LHC.
I shortly review time period of twelve years, 1989-2000, which was devoted to a theoretical support of experiments at LEP and SLC at Z resonance and discuss several directions of possible future work in the field of precision theoretical…
We have used YFS Monte Carlo techniques to obtain per-mil level accuracy for the Bhabha scattering cross section used in the luminosity monitor in electro-weak scattering experiments. We will describe techniques for extending these methods…
As experimental particle physics becomes more and more precise, it is becoming increasingly important for Monte Carlo simulations to improve the precision of their predictions. In terms of the hard matrix element, this means calculating to…
Using the OPAL detector at LEP, the running of the effective QED coupling alpha(t) is measured for space-like momentum transfer, 2 \leq -t \leq 6 GeV^2, from the angular distribution of small-angle Bhabha scattering. This is currently the…
The first-order eikonal approximation is frequently adopted in interpreting the results of $A(e,e'p)$ measurements. Glauber calculations, for example, typically adopt the first-order eikonal approximation. We present an extension of the…
The present paper deals with the generalization of Midpoint Ellipse Drawing Algorithm (MPEDA) to minimize the error in the existing MPEDA in cartesian form. In this method, we consider three different values of h, i.e., 1, 0.5 and 0.1. For…
We evaluate the two-loop QED corrections to the Bhabha scattering cross section which involve the vacuum polarization by heavy fermions of arbitrary mass m_f >> m_e. The results are valid for generic values of the Mandelstam invariants…