Problem with evaluating the Trace of Hadronic tensor of spin 3/2 particle

[yogeesh-dev]

Hello,

I am trying to evaluate the Diactrace using Feyncalc. The expression involves projection operator P which comes from completeness relation of spin 3/2 particles (Delta-). I am having some issues while evaluating this. can anyone help me with this?

[vsht]

I cannot reproduce this issue

P = (MT[mu, nu] - (1/3)*
   GA[mu] . 
    GA[nu] - (1/(3 MD))*(GA[mu]*FV[pd, nu] - 
     GA[nu]*FV[pd, mu]) + (2/(3 MD^2))*(FV[p, mu]*FV[p, nu] + 1))

DiracTrace[(GS[p] + MD) . GA[mu] . (1 - GA[5]) . P . (GS[p] + ML) . 
     GA[nu] . (1 - GA[5])] // DiracSimplify // FCE 
(*(32*FV[p, mu]*FV[p, nu])/(3*MD^2) + (16*SP[p, p])/3 - 
 (16*MT[mu, nu]*SP[p, p])/(3*MD^2) + (16*SP[p, p]^2)/(3*MD^2)*)

But the expression for P looks weird because of (FV[p, mu]*FV[p, nu] + 1))

[yogeesh-dev]

So, Did it work ?