Name: Manuel J. Vicente Date: 11/23/15-04:27:34 PM Z
Hi,
using F9.0.0 I get an strange result from FermionSpinSum:
part1 = Spinor[pp, m].(GA[mu] f1 + GA[mu, 5]
fa).Spinor[p, m]
part1cc = ComplexConjugate[part1] /. mu -> nu
aux=FermionSpinSum[part1cc part1]
aux/.DiracTrace->Tr
4*f1^2*(Pair[LorentzIndex[mu],
Momentum[pp]]*Pair[LorentzIndex[nu],
Momentum[p]] +
Pair[LorentzIndex[mu],
Momentum[p]]*Pair[LorentzIndex[nu],
Momentum[pp]] +
Pair[LorentzIndex[mu], LorentzIndex[nu]]*(m^2
The result is only a part of the full tensor. In fact, it doesn’t depend on fa at all! The correct result can be recovered just by
Tr[(DiracSlash[p] + m).(GA[nu] f1 - GA[5,
nu] fa).(DiracSlash[pp] +
m).(GA[mu] f1 + GA[mu, 5] fa)]
The simpler case with nu=mu also fails.
p.s. it works fine in the 8.2 version
best regards
Manuel J. Vicente