Name: Nikita Belyaev Date: 07/28/15-11:02:37 PM Z


Hi Vladyslav,

>The attached file is the code for your calculation in FORM. You can run
>it via
>
>form trace.frm

Thank you for that code!
I’ve tried to run it and here what I can see. Again considering terms with u^3 I’ve got the following set of expressions:

- 256*e_[k1,p,p1,s]*p2.k2*u^3 + 256*e_[k1,p,p1,k2]*p2.s*u^3 - 256*e_[k1,p,s,k2]*p1.p2*u^3+
+ 256*e_[k1,p1,p2,s]*p.k2*u^3 - 256*e_[k1,p1,p2,k2]*p.s*u^3 + 512*e_[k1,p1,s,k2]*p.p2*u^3-
- 256*e_[k1,p2,s,k2]*p.p1*u^3 - 256*e_[p,p1,s,k2]*k1.p2*u^3 + 256*e_[p1,p2,s,k2]*k1.p*u^3

It is very easy to see that by applying the Schouten identity twice we get that this sum is exactly zero as it should be!

Do you have any ideas why FeynCalc have a different output?

Best Regards,
Nikita Belyaev