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NLO QED corrections to ISR in e+ e- annihilation and the measurement of σ(e+ e- \to hadrons) using tagged photons

German Rodrigo·Aude Gehrmann-De Ridder·Marc Guilleaume·Johann H. Kuhn
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Abstract

The leptonic tensor for the process $e^+ e^- \to γ+γ^*$, which describes the next-to-leading order virtual and soft QED corrections to initial state radiation in $e^+ e^-$ annihilation with emission of an extra virtual photon decaying into hadrons, is calculated. A Monte Carlo generator for the reaction $e^+ e^- \to γ+ π^+ π^-$ has been set up which includes these corrections. It thus describes configurations where the invariant mass of the hadrons plus photon is very close to $\sqrt{s}$. Predictions for cms energies of 1 to 10 GeV, corresponding to the energies of DAPHNE and B-meson factories, are presented. The possibility for an accurate measurement using tagged photons of $σ(e^+ e^- \to hadrons)$, which plays an important role in the theoretical description of the muon anomalous magnetic moment and the running of the electromagnetic coupling, is discussed.

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German Rodrigo, Aude Gehrmann-De Ridder, Marc Guilleaume, Johann H. Kuhn. 2001-06-13. NLO QED corrections to ISR in e+ e- annihilation and the measurement of σ(e+ e- \to hadrons) using tagged photons. https://doi.org/10.1007/s100520100784

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