出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：We describe the calculation of the two–loop massive operator matrix elements with massive external fermions in QED. We investigate the factorization of the O(a2) initial state corrections to e+e− annihilation into a virtual boson for large cms energies s ≫ m2e into massive operator matrix elements and the massless Wilson coefficients of the Drell-Yan process adapting the color coefficients to the case of QED, as proposed by Berends et. al. in Ref. [1]. Our calculations show explicitly that the representation proposed in Ref. [1] works at one-loop order and up to terms linear in ln(s/m2e ) at two-loop order. However, the two-loop constant part contains a few structural terms, which have not been obtained in previous direct calculations.
