I need to import a new particle with spin zero

Hi,

This is correct, but in addition you need to define in the others file how your new particle couple to the other particle of your model.
In addition you also have to define the antiparticle in the model.
All the convention for the model are written in this paper: arXiv:1108.2040

Note that FeynRules can created a model from the Lagrangian which might be easier than editing the model by hand.

Cheers,

Olivier

> On Jan 6, 2016, at 14:37, Mai <email address hidden> wrote:
>
> New question #280618 on MadGraph5_aMC@NLO:
> https://answers.launchpad.net/mg5amcnlo/+question/280618
>
> Hi,
>
> I am new user of MadGraph5 and i need to understand how to import another particle to the DY-SM model.
>
> Iam trying to generate events for new particle with varouis masses , 200 , 500, 1000 ..... 4500 GeV and from my little knowledge till now: I can go to Models folder then edit manually the file "particles.py" by adding its pdg code and edit the below example as needed: (can I insert a new symbol to the particles or what is the steps to add a new particles ???)
>
> "MY_PARTICLE" = Particle(pdg_code = XXXX,
> name = 'MY_PARTICLE',
> antiname = 'MY_PARTICLE~',
> spin = 0,
> color = 1,
> mass = Param.ZERO,
> width = Param.ZERO,
> texname = 'MY_PARTICLE',
> antitexname = 'MY_PARTICLE',
> charge = 0,
> LeptonNumber = 1,
> GhostNumber = 0)
>
> Thanks,
>
> Mai
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

Thanks Olivier,

So Can I made a new model contains ONLY my needed particles or i should make a model contains all the SM particles plus mine?

For sure i will read the paper you sent me but i am trying to get an overview picture on what i am looking for.

Could you point me to any basic tutorials that shows how to understand MG5/ME step by step?

many thanks,

Mai

Hi,

> So Can I made a new model contains ONLY my needed particles or i should
> make a model contains all the SM particles plus mine?

If you want to do LHC physics then you need at least the constituent of the proton to be part of your model.
If you are only interested to unitarisation problem of your model and therefore mainly interested in 2>2 matrix element then not implementing the SM particles can be fine.

> Could you point me to any basic tutorials that shows how to understand
> MG5/ME step by step?

Here you are:
https://cp3.irmp.ucl.ac.be/projects/madgraph/wiki/Shanghai2015
You can look at the first tutorial in particular.
(note that the first step is just to type “tutorial” after opening the mg5 shell and follow instructions.

Cheers,

Olivier

> On Jan 7, 2016, at 09:26, Mai <email address hidden> wrote:
>
> Question #280618 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/280618
>
> Status: Answered => Open
>
> Mai is still having a problem:
> Thanks Olivier,
>
> So Can I made a new model contains ONLY my needed particles or i should
> make a model contains all the SM particles plus mine?
>
> For sure i will read the paper you sent me but i am trying to get an
> overview picture on what i am looking for.
>
> Could you point me to any basic tutorials that shows how to understand
> MG5/ME step by step?
>
> many thanks,
>
> Mai
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.