Two-loop electroweak next-to-leading logarithms for processes involving   heavy quarks
  We derive logarithmically enhanced two-loop virtual electroweak corrections for arbitrary fermion-scattering processes at the TeV scale. This extends results previously obtained for massless fermion scattering to processes that involve also bottom and top quarks. The contributions resulting from soft, collinear, and ultraviolet singularities in the complete electroweak Standard Model are explicitly extracted from two-loop diagrams to next-to-leading-logarithmic accuracy including all effects associated with symmetry breaking and Yukawa interactions. 
Ansgar Denner, Bernd Jantzen, Stefano Pozzorini