# mg@NLO with SMEFTatNLO

Hi,

I am using the model file SMEFTatNLO for a project work. But I am facing some issues. Here is what is happening: I have only kept the operator O_tz non-zero and have generated the process p p > t t~. The new physics contribution starts at QED=2. Still, when I am generating the above process with order QED=2 QCD=2 NP=2 [QCD], I am getting the warning "WARNING: All Born diagrams do not factorize the same sum of power(s) of the perturbed order(s) QCD.

This is potentially dangerous as the real-emission diagrams from aMC@NLO will not be consistent with these virtual contributions." and the lunch is getting terminated. But when I am generating the process with order QED=2 QCD=0 NP=2 [QCD], everything works fine. But as you can clearly see, in the second method I am losing many standard model diagrams (QED=1 QCD=2 NP=0), which will be present in the background events giving weird results. Can you please suggest the proper way to generate that process?

Note:

I tried generating that process with the following set of commands:

generate p p > t t~ QED=2 QCD=0 NP=2 [QCD]

add process p p > t t~ QED=1 QCD=2 NP=0 [QCD]

But, I am concerned that may be the interference term between the two sets of processes are not getting included. What are you thoughts.

Best,

Rameswar

## Question information

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- Solved

- Assignee:
- Eleni Vryonidou Edit question

- Solved by:
- Olivier Mattelaer

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