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hep-ph2008★ 4 cited
Irrational constants in positronium decays
B. A. Kniehl, A. V. Kotikov, O. L. Veretin
We establish irrational constants, that contribute to the positronium lifetime at and order. In particular we show, that a new type of constants appear, which are n…
hep-ph2007★ 61 cited
Two-Loop Formfactors in Theories with Mass Gap and Z-Boson Production
A. Kotikov, J. H. Kuhn, O. Veretin
The two-loop formfactor both for a U(1)xU(1) and a SU(2)xU(1) gauge theory with massive and massless gauge bosons respectively is evaluated at arbitrary momentum transfer q^2. The…