4muon Cross Section in the SM

Dear Jongkuk,

It’s difficult to know what you did. Especially I do not know where you found this 14fb number and what are the cut/selection associate to it.
Especially are you sure that they do not also include 4 electron?

Now you need to know that the following syntax:
import model sm
generate p p > mu+ mu- mu+ mu-

Do not include the gluon fusion process (since it is loop-induce) and therefore the Higgs contribution to that process.
However that contribution is not large enough to explain your difference. (you can have a pretty good estimation of that contribution via the heft model)

Cheers,

Olivier

On 25 Feb 2015, at 02:31, Jongkuk Kim <email address hidden> wrote:

> Question #262762 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/262762
>
> Description changed to:
> Dear MadGraphers,
>
> I am working on zprime model. First, I checked out 4muon cross section
> in the SM. Cross section (p p > 4muon) is about 14 fb in the SM from
> 8TeV LHC data. So, I tried to generate 4muon event using Madgraph and
> got result. However, the result is 7fb. I have no idea. When I
> generate a event, I typed generate p p > mu- mu+ mu- mu+ , and used cut
> information about pt,l >5GeV , m_ll > 5GeV. Could you explain it to me
> what make difference?
>
> best regards,
> Jongkuk
>
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