Individual cross section and corresponding diagram

Hi,

The document about this is here:
https://answers.launchpad.net/mg5amcnlo/+faq/2944

> However, for 'a a > h+ h-', in the matrix1.ps, the diagram1 comes from four-point vertex. However, I don't see the assignment of diagram 1 to any GXX. Thus I would like to ask How such diagram is assigned? (For e- e+ > e- e+ h+ h-, I also don't see the assignment of the diagrams involving four-point vertex to any GXX)

Four point diagram are by default not used for the channel of integration so indeed you will never have a channel GXXX associated to them. (the only case where this is not the case is if they are no diagram with only 3-point vertex.

> Further, I also would like to know more detail about GXX, as I can see like G1xxx, or G1.02 etc, what does this mean? Thanks!

The presence of .XX or .XXX means that madgraph identifies a breitwigner conflict in that channel of integration. The channel is then split in 3^N pieces (where N is the number of particles in breitwigner conflict)
and the value XX or XXX correspond to a ternary encoding of which particle is assume to be below his onshell mass, onshell or above his onshell mass.

Cheers,

Olivier

> On 5 Sep 2020, at 02:25, teddym <email address hidden> wrote:
>
> New question #692757 on MadGraph5_aMC@NLO:
> https://answers.launchpad.net/mg5amcnlo/+question/692757
>
> Dear MG authors:
> After calculating the cross section for some process, I want to have a check in the "HTML/run_01/results.html" page where I can see the individual contribution to the total cross section from each 'subprocess': GXX and have a sense about each contribution. From my old note, I can find the correspondence between GXX with the diagram from the 'P1_XX_XXXX/config_subproc_map.inc' file. Also 'P1_XX_XXXX/symfact.dat' indicates which GXX will be mirror of some other and be calculated together (am I right about this? I find this from my old note several years ago for which I can't find the original source).
>
> However, for 'a a > h+ h-', in the matrix1.ps, the diagram1 comes from four-point vertex. However, I don't see the assignment of diagram 1 to any GXX. Thus I would like to ask How such diagram is assigned? (For e- e+ > e- e+ h+ h-, I also don't see the assignment of the diagrams involving four-point vertex to any GXX)
>
> Further, I also would like to know more detail about GXX, as I can see like G1xxx, or G1.02 etc, what does this mean? Thanks!
>
>
> Best
> Ted Wu
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

Hi Olivier:
    Thanks for your answer.

    > Four point diagram are by default not used for the channel of integration so indeed you will never have a channel GXXX associated to them. (the only case where this is not the case is if they are no diagram with only 3-point vertex.

    Then, Does that mean I can't get a rough idea of what is the contribution from those four point diagrams? And since the sum of all GXX are the total cross section, I even can't have a rough sense of what are the contributions from other diagrams, as the four-point diagram is hidden behind that.

Thanks

Ted Wu

Thanks Olivier Mattelaer, that solved my question.