Loop functions

[Astro]

Dear sir,

I'd like to ask about the loop function generated in SARAH Tex files, like C_0(m1,m2,m3) , how can i generate there definitions ?
I know they are the three or two or four point functions and they have actually external references, but can I have a specific convention for them by SARAH ?

Thanks,
Astro

[FStaub]

These are standard loop integrals which you can find for instance in appendix C of https://arxiv.org/abs/1408.0138

Cheers
Florian

[Astro]

Hi,

Thanks for the reference, but I still find a function in SARAH'TeX files: I = B0C0check(m1^2,m2^2,m3^2) .. may i ask what's its definition ?

Best,
Astro

[FStaub]

Ah, yes, there are some special functions. The reason that divergencies might just cancel if you consider sums of loop functions. The combinations handled by SARAH in that way are

Code: Select all

B0[0,b_,a_]+c_ C0[a_,b_,c_]->B0C0check[a,b,c]
C0[a_,b_,c_]+ d_ D0[___,d_,___]->C0D0check[a,b,c,d]
mF1*mF2*D0[a__]->MMD0[mF1,mF2,a]

Cheers
Florian

[Astro]

Greetings ..
Astro