# KeyError : QED error in NLO calculation

Dear Olivier

I'm trying to calculate NLO corrections in Vprime model from feynrules which we just added NP flag for the new vertices. I'm trying to get the NLO corrections with MG5 v3. So I'm trying to get only QCD corrections without the NP corrections where im generating as follows

>generate p p > j j / wp+ wp- NP^2<=2 QCD=0 [QCD]

with NP<=2; I'm getting NP^2=4 corrections which I dont want, thats why I set NP^2<=2 but now I'm getting the following (I get same error when I set QED=0)

>INFO: Generating FKS-subtracted matrix elements for born process: g g > g g [ all = NP QED QCD ] NP^2<=2 QCD^2=200 / wp+ wp+ (1 / 200)

>INFO: Generating FKS-subtracted matrix elements for born process: g g > u u~ [ all = NP QED QCD ] NP^2<=2 QCD^2=200 / wp+ wp+ (2 / 200)

>Command "generate p p > j j / wp+ wp- NP^2<=2 QCD=0 [QCD]" interrupted with error:

>KeyError : 'QED'

>Please report this bug on https:/

>More information is found in 'MG5_debug'.

>Please attach this file to your report.

Note that this does not happen when I set NP=2, I get all the diagrams without a problem. Is there a way to solve this? Or can you tell me the correct command to achieve this?

MG5 v3_0_3

(I can't get rid of these corrections in v2.7.3 which ends up not canceling poles thats why im using v3. When I generate the process the same way in v2.7 it cant find any amplitudes.)

Thanks

## Question information

- Language:
- English Edit question

- Status:
- Answered

- Assignee:
- marco zaro Edit question

- Last query:
- 2020-09-14

- Last reply:
- 2020-09-14

Syntax specifiction in 3.0.3 are confusing since they do not match 2.x syntax for what you try to do.

This was a huge feedback of the beta release (this is one of the good point to still be in beta for that version) and will change the syntax in 3.0.4 to have a more consistent syntax.

For the moment you can use this branch: lp:~maddevelopers/mg5amcnlo/3.0.3-neworders

which implements such new syntax.

Cheers,

Olivier

Jack Y. Araz (jackaraz) said : | #2 |

Dear Olivier

Thanks a lot for the quick response. It seems like it solved the previous problem with QED but now I can't get any loop diagrams without SM (Z/W/a) contribution. So what I want is p p > j j where only contribution is coming from Z' + loop order corrections which I was achieving in v2.X via setting QCD=0. Now I tried

generate p p > j j / wp+ wp- NP=2 QCD=0 NP^2<=2 QED=0 [QCD]

but I get the following

Command "generate p p > j j / wp+ wp- NP=2 QCD=0 NP^2<=2 QED=0 [QCD]" interrupted with error:

FKSProcessError : This process does not have any correction up to NLO in QCD

when I set NP=2 QCD=2 NP^2<=2 QED=0 [QCD] it works but I get some diagrams without Z' which is expected. Is there a way to enforce to have Z' in the diagram and only have QCD loop corrections without any NP corrections?

Thanks

Best regards

Jack

marco zaro (marco-zaro) said : | #3 |

Hi Jack,

can you try

generate p p > j j / wp+ wp- NP=2 QCD^2=0 NP^2<=2 QED=0 [QCD]

?

(note QCD=0 -> QCD^2=0)

Let me know...

Where can I get the model, to try a bit myself?

Thanks,

Marcpo

Jack Y. Araz (jackaraz) said : | #4 |

Hi Marco;

Please see the link (https:/

> can you try

> generate p p > j j / wp+ wp- NP=2 QCD^2=0 NP^2<=2 QED=0 [QCD]

> ?

> (note QCD=0 -> QCD^2=0)

I get the following;

Command "generate p p > j j / wp+ wp- NP=2 QCD^2=0 NP^2<=2 QED=0 [QCD]" interrupted with error:

FKSProcessError : This process does not have any correction up to NLO in QCD

Thanks

Best regards

—

Jack Y. Araz

> On Sep 14, 2020, at 2:50 PM, marco zaro <email address hidden> wrote:

>

> Your question #692901 on MadGraph5_aMC@NLO changed:

> https:/

>

> Status: Open => Answered

>

> marco zaro proposed the following answer:

> Hi Jack,

> can you try

> generate p p > j j / wp+ wp- NP=2 QCD^2=0 NP^2<=2 QED=0 [QCD]

> ?

> (note QCD=0 -> QCD^2=0)

>

> Let me know...

> Where can I get the model, to try a bit myself?

>

> Thanks,

>

> Marcpo

>

> --

> If this answers your question, please go to the following page to let us

> know that it is solved:

> https:/

>

> If you still need help, you can reply to this email or go to the

> following page to enter your feedback:

> https:/

>

> You received this question notification because you asked the question.

marco zaro (marco-zaro) said : | #5 |

Hi,

are you sure the model is correct?

If I generate a LO process with your syntax I also get errors:

MG5_aMC>generate u u~ > d d~ / wp+ wp- NP=2 QCD=0 NP^2<=2 QED=0

Interpreting 'NP=2' as 'NP<=2'

Command "generate u u~ > d d~ / wp+ wp- NP=2 QCD=0 NP^2<=2 QED=0 " interrupted in sub-command:

"generate u u~ > d d~ / wp+ wp- NP=2 QCD=0 NP^2<=2 QED=0" with error:

NoDiagramException : No amplitudes generated from process Process: u u~ > d d~ / wp+ wp+ NP=2 QCD=0 QED=0 NP^2<=2 @1. Please enter a valid process

Please report this bug on https:/

More information is found in 'MG5_debug'.

Please attach this file to your report.

Marco

marco zaro (marco-zaro) said : | #6 |

sorry, It should be NP^2 <= 4, not 2, right?

Cheers,

Marco

> On 14 Sep 2020, at 16:10, marco zaro <email address hidden> wrote:

>

> Question #692901 on MadGraph5_aMC@NLO changed:

> https:/

>

> Status: Open => Needs information

>

> marco zaro requested more information:

> Hi,

> are you sure the model is correct?

> If I generate a LO process with your syntax I also get errors:

> MG5_aMC>generate u u~ > d d~ / wp+ wp- NP=2 QCD=0 NP^2<=2 QED=0

> Interpreting 'NP=2' as 'NP<=2'

> Command "generate u u~ > d d~ / wp+ wp- NP=2 QCD=0 NP^2<=2 QED=0 " interrupted in sub-command:

> "generate u u~ > d d~ / wp+ wp- NP=2 QCD=0 NP^2<=2 QED=0" with error:

> NoDiagramException : No amplitudes generated from process Process: u u~ > d d~ / wp+ wp+ NP=2 QCD=0 QED=0 NP^2<=2 @1. Please enter a valid process

> Please report this bug on https:/

> More information is found in 'MG5_debug'.

> Please attach this file to your report.

>

> Marco

>

> --

> You received this question notification because you are assigned to this

> question.

Jack Y. Araz (jackaraz) said : | #7 |

Hi Marco

When I set 'generate p p > j j NP=2 QCD=0 QED=0’ I can see all the NP diagrams at LO in both versions so I believe there is no problem at LO, please let me know if im wrong. So yes I believe NP^2 should be <=4, which gives me same diagrams as the command above. In the meantime I’m checking the model, couldn’t find a problem so far.

Thanks

Best regards

—

Jack Y. Araz

> On Sep 14, 2020, at 3:15 PM, marco zaro <email address hidden> wrote:

>

> Your question #692901 on MadGraph5_aMC@NLO changed:

> https:/

>

> Status: Needs information => Answered

>

> marco zaro proposed the following answer:

> sorry, It should be NP^2 <= 4, not 2, right?

> Cheers,

> Marco

>

>> On 14 Sep 2020, at 16:10, marco zaro <email address hidden> wrote:

>>

>> Question #692901 on MadGraph5_aMC@NLO changed:

>> https:/

>>

>> Status: Open => Needs information

>>

>> marco zaro requested more information:

>> Hi,

>> are you sure the model is correct?

>> If I generate a LO process with your syntax I also get errors:

>> MG5_aMC>generate u u~ > d d~ / wp+ wp- NP=2 QCD=0 NP^2<=2 QED=0

>> Interpreting 'NP=2' as 'NP<=2'

>> Command "generate u u~ > d d~ / wp+ wp- NP=2 QCD=0 NP^2<=2 QED=0 " interrupted in sub-command:

>> "generate u u~ > d d~ / wp+ wp- NP=2 QCD=0 NP^2<=2 QED=0" with error:

>> NoDiagramException : No amplitudes generated from process Process: u u~ > d d~ / wp+ wp+ NP=2 QCD=0 QED=0 NP^2<=2 @1. Please enter a valid process

>> Please report this bug on https:/

>> More information is found in 'MG5_debug'.

>> Please attach this file to your report.

>>

>> Marco

>>

>> --

>> You received this question notification because you are assigned to this

>> question.

>

> --

> If this answers your question, please go to the following page to let us

> know that it is solved:

> https:/

>

> If you still need help, you can reply to this email or go to the

> following page to enter your feedback:

> https:/

>

> You received this question notification because you asked the question.

marco zaro (marco-zaro) said : | #8 |

Hi Jack,

since the diagram you want contains 2 NP vertices, then you have to specify NP^2=4 (or not specify squared orders at all).

Cheers,

Marco

> On 14 Sep 2020, at 18:00, Jack Y. Araz <email address hidden> wrote:

>

> Question #692901 on MadGraph5_aMC@NLO changed:

> https:/

>

> Status: Answered => Open

>

> Jack Y. Araz is still having a problem:

> Hi Marco

>

> When I set 'generate p p > j j NP=2 QCD=0 QED=0’ I can see all the NP

> diagrams at LO in both versions so I believe there is no problem at LO,

> please let me know if im wrong. So yes I believe NP^2 should be <=4,

> which gives me same diagrams as the command above. In the meantime I’m

> checking the model, couldn’t find a problem so far.

>

> Thanks

> Best regards

>

> —

> Jack Y. Araz

>

>> On Sep 14, 2020, at 3:15 PM, marco zaro <email address hidden> wrote:

>>

>> Your question #692901 on MadGraph5_aMC@NLO changed:

>> https:/

>>

>> Status: Needs information => Answered

>>

>> marco zaro proposed the following answer:

>> sorry, It should be NP^2 <= 4, not 2, right?

>> Cheers,

>> Marco

>>

>>> On 14 Sep 2020, at 16:10, marco zaro <email address hidden> wrote:

>>>

>>> Question #692901 on MadGraph5_aMC@NLO changed:

>>> https:/

>>>

>>> Status: Open => Needs information

>>>

>>> marco zaro requested more information:

>>> Hi,

>>> are you sure the model is correct?

>>> If I generate a LO process with your syntax I also get errors:

>>> MG5_aMC>generate u u~ > d d~ / wp+ wp- NP=2 QCD=0 NP^2<=2 QED=0

>>> Interpreting 'NP=2' as 'NP<=2'

>>> Command "generate u u~ > d d~ / wp+ wp- NP=2 QCD=0 NP^2<=2 QED=0 " interrupted in sub-command:

>>> "generate u u~ > d d~ / wp+ wp- NP=2 QCD=0 NP^2<=2 QED=0" with error:

>>> NoDiagramException : No amplitudes generated from process Process: u u~ > d d~ / wp+ wp+ NP=2 QCD=0 QED=0 NP^2<=2 @1. Please enter a valid process

>>> Please report this bug on https:/

>>> More information is found in 'MG5_debug'.

>>> Please attach this file to your report.

>>>

>>> Marco

>>>

>>> --

>>> You received this question notification because you are assigned to this

>>> question.

>>

>> --

>> If this answers your question, please go to the following page to let us

>> know that it is solved:

>> https:/

>>

>> If you still need help, you can reply to this email or go to the

>> following page to enter your feedback:

>> https:/

>>

>> You received this question notification because you asked the question.

>

> --

> You received this question notification because you are assigned to this

> question.

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