出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：The dominant contribution of the next-to-leading order perturbative QCD corrections to the ¡!
Xg photon energy spectrum for photon energies w mbas can be obtained trivially from the
knowledge of the corresponding O(a) correction to the positronium decay spectrum in the same
region. The latter can be obtained from the NRQED computation of the orthopositronium photon
spectrum, or by applying the threshold expansion to the 1-loop QED amplitude, as it is explained
in this talk.
