# Identifying Contributions of different Parameter orders in MG v3.1.X

Dear experts,

I'm generating events with MG5 v3.1.0 at NLO. The model I use is designed to simulate processes under consideration of EFT effects and introduces a parameter for the orders of new physics (NP) beyond the SM. The model also introduces new parameters which control the contribution of new operators.

I would like to generate the different contributions to the overall cross section, i.e. the pure EFT part and the interference terms, separately. However, I'm still a novice in MG, so I'm not sure how to do this correctly. As far as I know, syntax like NP^2==X does not work in the NLO mode. So I came up with the following options

1) Calculate the processes with NP^2=X, which will generate more contributions than I want. I should then be able to extract the individual components by subtracting cross sections. For example, if I generate NP^2=0 (i.e. the SM) and NP^2=2 (i.e. the pure EFT part + SM) and subtract the two, I should get the pure EFT part.

2) Use the information given of the orders_tag_plot feature in MG v3.1.X. Here, I would have to select and add the components with NP==2 to get the pure EFT part.

Here are my questions: Can I really do it like this? Are the two options equivalent (if they are valid at all)? Are there any pitfalls that I should be aware of?

Thanks in advance for your help!

Cheers,

Philip

## Question information

- Language:
- English Edit question

- Status:
- Solved

- Assignee:
- Eleni Vryonidou Edit question

- Solved by:
- Eleni Vryonidou

- Solved:

- Last query:

- Last reply: