FEYN CALC SYMBOL

TID


performs tensor decomposition of 1-loop integrals with loop momentum q

ExamplesExamplesopen allclose all

Basic Examples  (1)Basic Examples  (1)

In[1]:=
Click for copyable input
Out[1]=
In[2]:=
Click for copyable input
Out[2]=
  • By default, all the tensor integrals are reduced to the Passarino-Veltman scalar integrals , , , etc.
  • In[3]:=
    Click for copyable input
    Out[3]=
  • Scalar integrals can be converted to the Passarino-Veltman notation via the option ToPaVe
  • In[4]:=
    Click for copyable input
    Out[4]=
  • We can force the reduction algorithm to use Passarino-Veltman coefficient functions via the option UsePaVeBasis
  • In[5]:=
    Click for copyable input
    Out[5]=
  • The basis of Passarino-Veltman coefficient functions is used automatically if there are zero Gram determinants
  • In[6]:=
    Click for copyable input
    Out[6]=
  • In FeynCalc, Passarino-Veltman coefficient functions are defined in the same way as in LoopTools, which is a quite common convention. If one wants to use a different definition, it is useful to activate the option GenPaVe
  • In[7]:=
    Click for copyable input
    Out[7]=