Role of the top quark mass in b production at future lepton colliders - art. no. 011301

We compute the one loop contribution coming from vertex and box diagrams, w here virtual top quarks are exchanged, to the asymptotic energy behavior of b (b) over bar pair production at future lepton colliders. We find that th e effect of the top quark mass is an extra linear logarithmic term of Sudak ov type that is not present in the case of (u,d,s,c) production. This appea rs to be particularly relevant in the case of the b (b) over bar cross sect ion.