Four-fermions operator

I tried to add an auxiliary field in this way

read stand.
let AA = AuxPrt(1,0,0).
lterm (anti(psi)*gamma*psi)*AA
  where
   psi = u.

If now I use FeynCalc patched to work with FeynArts I get errors
https://s31.postimg.org/3yl1a7nor/Screen_Shot_2016_07_01_at_10_54_01_AM.png

If I use just FeynArts not patched, It works but in this way I don't know how to implement it in FeynCalc, this is the screenshot https://s32.postimg.org/sc0ll60n9/Screen_Shot_2016_07_01_at_10_57_33_AM.png

It is strange.

I add

lterm U*gamma*u*E1*gamma*e1.

to

lanhep320/mdl/stand.mdl

Then I call from lanhep320/mdl directory

    ../lhep -ca stand.mdl

And LanHEP generates me 4-fermion vertex via auxiliary particle

UuE1e1 |~00|~01| |2 |Maux|0 |1 |!*

U |u |~01 | |i*Maux |G(m3)
E1 |e1 |~00 | |i*Maux |G(m3)

So, it works. Take source file

  http://theory.simp.msu.ru/~pukhov/stand.mdl

Best
     Alexander Pukhov

On 06/30/2016 07:02 PM, apt45 wrote:
> New question #295816 on CalcHEP:
> https://answers.launchpad.net/calchep/+question/295816
>
> Hi CalcHEP team,
> I tried to introduce a four-quarks operator like
>
> $\bar{q}\gamma^\mu P_L q \bar{q}\gamma_\mu P_L q $.
>
> Since I am a newbie, I decided to try with a simpler model than this one, so for example a 4-fermions operator like
>
> read stand.
> lterm U*u*E2*e2.
>
> This works and I can import in into FeynArts.
> But, when I try to introduce gamma matrices, for example
> lterm U*gamma*u*E2*gamma*e2.
> or
> lterm U*gamma^mu*u*E2*gamma^mu*e2.
>
> I get
>
> File sm_tex processed, 0 sec.
> File stand processed, 0 sec.
> File mdl/mymodel.mdl processed, 0 sec.
>
> Writing model4.mod...
> Internal error: (U, u, E2, e2)lost gamma index:mterm(1, _, [special(gamma, [1, 3, 7]), special(gamma, [5, 8, 7]), special('(1+gamma5)/2', [8, 6])])
> Internal error: (U, u, E2, e2)lost gamma index:mterm(1, _, [special(gamma, [1, 3, 7]), special(gamma, [5, 8, 7]), special('(1-gamma5)/2', [8, 6])])
> Internal error: (U, u, E2, e2)lost gamma index:mterm(1, _, [special(gamma, [1, 3, 7]), special(gamma, [5, 8, 7]), special('(1+gamma5)/2', [8, 6])])
> Internal error: (U, u, E2, e2)lost gamma index:mterm(1, _, [special(gamma, [1, 3, 7]), special(gamma, [5, 8, 7]), special('(1-gamma5)/2', [8, 6])])
> Writing model4.h, mdl_ini4.F...
> Writing model4.gen...
>
> Same thing for the more complicated operator
> this is the complicated mymodel.mdl
>
> read stand.
> lterm (anti(psi)*gamma*(1-gamma5)/2*psi)*(anti(psi)*gamma*(1-gamma5)/2*psi) where
> psi=q1; psi=q2; psi=q3.
>
> And when I launch ./lhep -fa mdl/mymodel.mdl I get
> File sm_tex processed, 0 sec.
> File stand processed, 0 sec.
> File mdl/mymodel.mdl processed, 0 sec.
>
> Writing model4.mod...
> Internal error: (B, b, B, b)lost gamma index:mterm(1, _, [special(gamma, [1, 9, 10]), special('(1-gamma5)/2', [9, 3]), special(gamma, [5, 11, 10]), special('(1-gamma5)/2', [11, 7])])
> Internal error: (B, b, T, t)lost gamma index:mterm(1, _, [special(gamma, [1, 9, 10]), special('(1-gamma5)/2', [9, 3]), special(gamma, [5, 11, 10]), special('(1-gamma5)/2', [11, 7])])
> Internal error: (C, c, C, c)lost gamma index:mterm(1, _, [special(gamma, [1, 9, 10]), special('(1-gamma5)/2', [9, 3]), special(gamma, [5, 11, 10]), special('(1-gamma5)/2', [11, 7])])
> Internal error: (C, c, S, s)lost gamma index:mterm(1, _, [special(gamma, [1, 9, 10]), special('(1-gamma5)/2', [9, 3]), special(gamma, [5, 11, 10]), special('(1-gamma5)/2', [11, 7])])
> Internal error: (D, d, D, d)lost gamma index:mterm(1, _, [special(gamma, [1, 9, 10]), special('(1-gamma5)/2', [9, 3]), special(gamma, [5, 11, 10]), special('(1-gamma5)/2', [11, 7])])
> Internal error: (D, d, U, u)lost gamma index:mterm(1, _, [special(gamma, [1, 9, 10]), special('(1-gamma5)/2', [9, 3]), special(gamma, [5, 11, 10]), special('(1-gamma5)/2', [11, 7])])
> Internal error: (S, s, C, c)lost gamma index:mterm(1, _, [special(gamma, [1, 9, 10]), special('(1-gamma5)/2', [9, 3]), special(gamma, [5, 11, 10]), special('(1-gamma5)/2', [11, 7])])
> Internal error: (S, s, S, s)lost gamma index:mterm(1, _, [special(gamma, [1, 9, 10]), special('(1-gamma5)/2', [9, 3]), special(gamma, [5, 11, 10]), special('(1-gamma5)/2', [11, 7])])
> Internal error: (T, t, B, b)lost gamma index:mterm(1, _, [special(gamma, [1, 9, 10]), special('(1-gamma5)/2', [9, 3]), special(gamma, [5, 11, 10]), special('(1-gamma5)/2', [11, 7])])
> Internal error: (T, t, T, t)lost gamma index:mterm(1, _, [special(gamma, [1, 9, 10]), special('(1-gamma5)/2', [9, 3]), special(gamma, [5, 11, 10]), special('(1-gamma5)/2', [11, 7])])
> Internal error: (U, u, D, d)lost gamma index:mterm(1, _, [special(gamma, [1, 9, 10]), special('(1-gamma5)/2', [9, 3]), special(gamma, [5, 11, 10]), special('(1-gamma5)/2', [11, 7])])
> Internal error: (U, u, U, u)lost gamma index:mterm(1, _, [special(gamma, [1, 9, 10]), special('(1-gamma5)/2', [9, 3]), special(gamma, [5, 11, 10]), special('(1-gamma5)/2', [11, 7])])
> Internal error: (B, b, B, b)lost gamma index:mterm(1, _, [special(gamma, [1, 9, 10]), special('(1-gamma5)/2', [9, 3]), special(gamma, [5, 11, 10]), special('(1-gamma5)/2', [11, 7])])
> Internal error: (B, b, T, t)lost gamma index:mterm(1, _, [special(gamma, [1, 9, 10]), special('(1-gamma5)/2', [9, 3]), special(gamma, [5, 11, 10]), special('(1-gamma5)/2', [11, 7])])
> Internal error: (C, c, C, c)lost gamma index:mterm(1, _, [special(gamma, [1, 9, 10]), special('(1-gamma5)/2', [9, 3]), special(gamma, [5, 11, 10]), special('(1-gamma5)/2', [11, 7])])
> Internal error: (C, c, S, s)lost gamma index:mterm(1, _, [special(gamma, [1, 9, 10]), special('(1-gamma5)/2', [9, 3]), special(gamma, [5, 11, 10]), special('(1-gamma5)/2', [11, 7])])
> Internal error: (D, d, D, d)lost gamma index:mterm(1, _, [special(gamma, [1, 9, 10]), special('(1-gamma5)/2', [9, 3]), special(gamma, [5, 11, 10]), special('(1-gamma5)/2', [11, 7])])
> Internal error: (D, d, U, u)lost gamma index:mterm(1, _, [special(gamma, [1, 9, 10]), special('(1-gamma5)/2', [9, 3]), special(gamma, [5, 11, 10]), special('(1-gamma5)/2', [11, 7])])
> Internal error: (S, s, C, c)lost gamma index:mterm(1, _, [special(gamma, [1, 9, 10]), special('(1-gamma5)/2', [9, 3]), special(gamma, [5, 11, 10]), special('(1-gamma5)/2', [11, 7])])
> Internal error: (S, s, S, s)lost gamma index:mterm(1, _, [special(gamma, [1, 9, 10]), special('(1-gamma5)/2', [9, 3]), special(gamma, [5, 11, 10]), special('(1-gamma5)/2', [11, 7])])
> Internal error: (T, t, B, b)lost gamma index:mterm(1, _, [special(gamma, [1, 9, 10]), special('(1-gamma5)/2', [9, 3]), special(gamma, [5, 11, 10]), special('(1-gamma5)/2', [11, 7])])
> Internal error: (T, t, T, t)lost gamma index:mterm(1, _, [special(gamma, [1, 9, 10]), special('(1-gamma5)/2', [9, 3]), special(gamma, [5, 11, 10]), special('(1-gamma5)/2', [11, 7])])
> Internal error: (U, u, D, d)lost gamma index:mterm(1, _, [special(gamma, [1, 9, 10]), special('(1-gamma5)/2', [9, 3]), special(gamma, [5, 11, 10]), special('(1-gamma5)/2', [11, 7])])
> Internal error: (U, u, U, u)lost gamma index:mterm(1, _, [special(gamma, [1, 9, 10]), special('(1-gamma5)/2', [9, 3]), special(gamma, [5, 11, 10]), special('(1-gamma5)/2', [11, 7])])
> Writing model4.h, mdl_ini4.F...
> Writing model4.gen...
>
>
> What is the problem?
>
>
>

I know nothing about LanHEP for FeynArts.
  You have to ask author of LanHEP Andrei Semenov directly.
<email address hidden> <mailto:<email address hidden>>
He does not get mails via CalcHEP.
Best
     Alexander Pukhov

On 07/01/2016 12:02 PM, apt45 wrote:
> Question #295816 on CalcHEP changed:
> https://answers.launchpad.net/calchep/+question/295816
>
> apt45 gave more information on the question:
> I tried to add an auxiliary field in this way
>
> read stand.
> let AA = AuxPrt(1,0,0).
> lterm (anti(psi)*gamma*psi)*AA
> where
> psi = u.
>
> If now I use FeynCalc patched to work with FeynArts I get errors
> https://s31.postimg.org/3yl1a7nor/Screen_Shot_2016_07_01_at_10_54_01_AM.png
>
> If I use just FeynArts not patched, It works but in this way I don't
> know how to implement it in FeynCalc, this is the screenshot
> https://s32.postimg.org/sc0ll60n9/Screen_Shot_2016_07_01_at_10_57_33_AM.png
>