Name: Gilberto Tavares Date: 04/24/03-10:32:32 AM Z


Hi, Peter:

Thanks for your message. Yes, I do agree that the inconsistency arises from
the ordering of the denominators. In fact, one can try the DenominatorOrder
option in the OneLoop function. For instance, I have evaluated the following
cells:

In[1]:= «HighEnergyPhysics`fc`

In[2]:= T1 = OneLoop[k, FVD[k,a]SPD[k,p]SPD[k]FAD[{k,my}, {k+p-q,mw},
{k+p+q,mw}], DenominatorOrder -> False];

In[3]:= T2 = OneLoop[k,FVD[k,a]SPD[k,p]SPD[k]FAD[{k,my}, {k+p-q,mw},
{k+p+q,mw}], DenominatorOrder -> True];

In[4]:= SetOptions[B0, BReduce -> True];

In[5]:= Simplify[PaVeReduce[T1 - T2]]

Out[5]:= I/48*Pi^2*(FV[p,a] + FV[q,a])*(2*mw^2 + 4*my^2 - SP[p, p] - 2*SP[p,
q] - SP[q, q])

This nonzero result means that there is the possibility that somewhere in
the OneLoop code there is a problem with the way it handles the ordering of
the denominators, I guess.