1,721,013 research outputs found
Universal Curve for pi pi Scattering Lengths by Optimal Extrapolation Techniques
No full textUsing the method of optimal extrapolation to interior points, we re-evaluate the equation of the universal curve of the ππs-wave scattering lengths. We reproduce the gross features of previous determinations, but with a realistic error, without any detailed assumption on the asymptotic behaviour. Possible implications of our result on the numerical value of thep-wave scattering length are qualitatively discussed
STRONG-INTERACTION CONTRIBUTIONS TO ONE-LOOP LEPTONIC PROCESSES
No full textWe classify all strong-interaction contributions to all four-lepton processes through one loop in electroweak SU2×U1 and to all orders in strong interactions. We show that those parts which are not reliably calculated in perturbative QCD are all related to a certain integral over the total cross section for e+e-hadrons at low energies. We evaluate this integral for the most recent data and find that, for most four-lepton processes of interest, it is dominated by the timelike q2 region from 1 to 100 GeV2. We show that the associated theoretical strong-interaction uncertainty is a factor of 2 smaller than previously published estimates. We give the strong-interaction contribution and associated theoretical uncertainty for future SLAC, CERN, and Fermilab precision experiments and show that the theoretical uncertainty is quite small, thus allowing precision tests of the electroweak theory at the one-loop level. © 1987 The American Physical Society
The role of universal and non universal Sudakov logarithms in four fermion processes at TeC energies: The one-loop approximation revisited.
No full textLogarithmic supersymmetric electroweak effects on four-fermion processes at TeV energies
No full textIs The Froissart Bound Saturated In Proton Proton Scattering?
No full textProton-proton and antiproton-proton forward data are analysed in the framework of a recently suggested stable unbiased approach to the asymptotic properties of total cross-sections. The resulting picture favours values of the leading logarithmic coefficient α such that 0≤α≲1
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