FEYN CALC SYMBOL

Spinor


is the head of Dirac spinors. Which of the spinors u, v, , or is understood, depends on the sign of the momentum (p) argument and the relative position of DiracSlash[p]: Spinor[sign p, mass] is that spinor which yields: sign*mass*Spinor[p, mass] if the Dirac equation is applied (by DiracEquation or DiracSimplify). The optional argument o can be used for additional degrees of freedom. If no optional argument o is supplied, a 1 is subsituted in. Spinors of fermions of mass m are normalized to have square u=2 m and v=-2 m.

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]=
FeynCalc uses covariant normalization (as opposed to e.g. the normalization used in Bjorken&Drell).
In[3]:=
Click for copyable input
Out[3]=
In[4]:=
Click for copyable input
Out[4]=
In[5]:=
Click for copyable input
Out[5]//StandardForm=
By convention, ChangeDimension does not operate on momenta in Spinor's (but on e.g. DiracSlash[Momentum[p]]).
In[6]:=
Click for copyable input
Out[6]//StandardForm=
In[7]:=
Click for copyable input
Out[7]//StandardForm=
SmallVariable's are discarded by Spinor.
In[8]:=
Click for copyable input
Out[8]//StandardForm=