The back-to-back region in e^+e^- energy--energy correlation

Abstract

We consider the back-to-back region in the energy--energy correlation in e^+e^- collisions. We present the explicit expression of the O(as^2) logarithmically enhanced contributions up to next-to-next-to-leading logarithmic accuracy. We study the impact of the results in a detailed comparison with precise LEP and SLC data. We find that, when hadronization effects are taken into account as is customarily done in QCD analysis in e^+e^- annihilations, the extracted value of as(M_Z) is in good agreement with the current world average.