109 research outputs found
QED collinear radiation factors in the next-to-leading logarithmic approximation
The effect of the collinear photon radiation by charged particles is
considered in the second order of the perturbation theory. Double and single
photon radiation is evaluated. The corresponding radiation factors are
obtained. The QED renormalization group approach is exploited in the
next-to-leading order. The results are suited to perform a systematic treatment
of the second order next-to-leading logarithmic radiative corrections to
various processes either analytically or numerically.Comment: 8 page
One-Loop Corrections to Radiative Muon Decay
One-loop QED corrections to the differential width of radiative muon decay
are considered. Results can be used to analyze high statistics data of modern
and future experiments.Comment: 16 pp, 3 PostScript figure
Radiative corrections to the background of decay
Radiative muon decay in the kinematics similar to the neutrinoless decay
is considered. Radiative corrections due to 1-loop virtual
photons and emission of additional soft or hard photons are taken into account.
Analytical expressions and numerical estimations are presented.Comment: 11 pages, LaTeX, misprints in Eqs.(9,12,14) fixe
Non-singlet splitting functions in QED
Iterative solution of QED evolution equations for non-singlet electron
structure functions is considered. Analytical expressions in the fourth and
fifth orders are presented in terms of splitting functions. Relation to the
existing exponentiated solution is discussed.Comment: 8 pages, LaTeX2
First Order Radiative Corrections to Polarized Muon Decay Spectrum
The first order QED corrections to the polarized muon decay spectrum are
considered. The exact dependence on electron and muon masses is kept. Numerical
results are presented.Comment: 11 pages, elsart.cls, a typo in Eq.(12) is fixe
Emission of Two Hard Photons in Large-Angle Bhabha Scattering
A closed expression for the differential cross section of the large-angle
Bhabha scattering which explicitly takes into account the leading and
next-to-leading contributions due to the emission of two hard photons is
presented. Both collinear and semi-collinear kinematical regions are
considered. The results are illustrated by numerical calculations.Comment: 13 pages, LaTeX, 1 PostScript figure, submitted to Nucl. Phys.
Radiative Corrections to Neutrino Deep Inelastic Scattering Revisited
Radiative corrections to neutrino deep inelastic scattering are revisited.
One-loop electroweak corrections are re-calculated within the automatic SANC
system. Terms with mass singularities are treated including higher order
leading logarithmic corrections. Scheme dependence of corrections due to weak
interactions is investigated. The results are implemented into the data
analysis of the NOMAD experiment. The present theoretical accuracy in
description of the process is discussed.Comment: 19 pages, two figures are added, discussion of theoretical
uncertainties is extende
O(\alpha^2 \ln(m_\mu/m_e)) Corrections to Electron Energy Spectrum in Muon Decay
O(\alpha^2 \ln(m_\mu/m_e)) corrections to electron energy spectrum in muon
decay are computed using perturbative fragmentation function approach. The
magnitude of these corrections is comparable to anticipated precision of the
TWIST experiment at TRIUMF where Michel parameters will be extracted from the
measurement of the electron energy spectrum in muon decay.Comment: 8 pages, LaTeX, revtex4.cls, 1 PostScript figur
Small-Angle Bhabha Scattering at LEP1. Analytical Results for Wide-Narrow Angular Acceptance
Analytical formulae for small-angle Bhabha scattering cross-section at LEP1
are given for the case of wide-narrow angular acceptance. Inclusive and
calorimeter event selections are considered. Numerical results are presented.Comment: 13 pages, LaTeX, submitted to Phys. Lett. B, corrected according to
referee remark
Calculation of the Two-Loop Heavy-Flavor Contribution to Bhabha Scattering
We describe in detail the calculation of the two-loop corrections to the QED
Bhabha scattering cross section due to the vacuum polarization by heavy
fermions. Our approach eliminates one mass scale from the most challenging part
of the calculation and allows us to obtain the corrections in a closed
analytical form. The result is valid for arbitrary values of the heavy fermion
mass and the Mandelstam invariants, as long as s,t,u >> m_e^2.Comment: 43 pages, 8 figures; added reference
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