Can I use MG5 for generating signal of our choice only out of many processes

Asked by SUBHASISH BEHERA on 2018-08-24

Dear MG5 team,

Can I use MG5 for generating signal of our choice out of many possibility ?

Detail:
I want to have final state as "b~ t mu- vm~".
I want to check cross section for b-mediated process only, no other process, can I do that ?
At the same time I don' t want the b-mediator to be on-shell.

Thanks in advance.

Thanks,
Subhasish

Question information

Language:
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Status:
Solved
For:
MadGraph5_aMC@NLO Edit question
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Solved by:
SUBHASISH BEHERA
Solved:
2018-08-24
Last query:
2018-08-24
Last reply:
2018-08-24

Hi,

Not sure to understand what you want.

But you can do something like this:
generate p p > b | b~ > b~ t mu- vm~

> At the same time I don' t want the b-mediator to be on-shell.

Well, Do you have a width for the b quark? If you do not, the above statement does not make sense to me.
If you do, you can remove the onshell contribution via the syntax:
generate p p > b | b~ > b~ t mu- vm~ $ b b~

Note that such syntax can break gauge (and consequently lorentz invariance) so this is YOUR responsablity that the set of diagram that you keep are gauge invariant.

Cheers,

Olivier

> On 24 Aug 2018, at 15:52, SUBHASISH BEHERA <email address hidden> wrote:
>
> New question #672674 on MadGraph5_aMC@NLO:
> https://answers.launchpad.net/mg5amcnlo/+question/672674
>
> Dear MG5 team,
>
> Can I use MG5 for generating signal of our choice out of many possibility ?
>
> Detail:
> I want to have final state as "b~ t mu- vm~".
> I want to check cross section for b-mediated process only, no other process, can I do that ?
> At the same time I don' t want the b-mediator to be on-shell.
>
>
> Thanks in advance.
>
> Thanks,
> Subhasish
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

Dear Olivier,

I was indicating a process at ILC where I want to generate :
e- e+ > t b~ mu- vm~ : Mediated via e- e+ > b b~ , b> w+ t

But when I was trying to do :
generate e- e+ > t b~ mu- vm~ / w- vm ve : it shows error as w-, w+ have to appear in the secondary vertex of the process
so that the process can exist.

Now if I want to generate process with b-mediator. i.e., the exact process looks like :
e- e+ > z>b b~, b> t w-, w->mu- vm~ : Can you imagine the diagram from this ?

I just want to calculate this process.

Sorry for bothering you.

Thanks,
Subhasish

It was working.

Thanks.

Is this not just replacing p p by e+ e- in my example above?

Cheers,

Olivier

> On 24 Aug 2018, at 22:52, SUBHASISH BEHERA <email address hidden> wrote:
>
> Question #672674 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/672674
>
> Status: Answered => Open
>
> SUBHASISH BEHERA is still having a problem:
> Dear Olivier,
>
> I was indicating a process at ILC where I want to generate :
> e- e+ > t b~ mu- vm~ : Mediated via e- e+ > b b~ , b> w+ t
>
> But when I was trying to do :
> generate e- e+ > t b~ mu- vm~ / w- vm ve : it shows error as w-, w+ have to appear in the secondary vertex of the process
> so that the process can exist.
>
> Now if I want to generate process with b-mediator. i.e., the exact process looks like :
> e- e+ > z>b b~, b> t w-, w->mu- vm~ : Can you imagine the diagram from this ?
>
> I just want to calculate this process.
>
> Sorry for bothering you.
>
>
> Thanks,
> Subhasish
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.