Can not combine LO/NLO feature.

Asked by SooJin Lee on 2019-11-08

Hi Madgraph staff.

I calculated some process with model DMsimp_s_spin0.

I want to calculate 'p p > xd xd~ [QCD] /a z w+ w- ' and 'p p > xd xd~ j[QCD] /a z w+ w-' together.

Each process worked well. but if I do 'add process', it didn't work.

error message is

"Command "add process p p > xd xd~ j[QCD] /a z w+ w-" interrupted with error:
InvalidCmd : Command not compatible with previous command: Can not combine LO/NLO feature."

Could you help me?

Thanks a lot.
-----------------------------------------------------------------------------------------------------------------------------------------------------------

MG5_aMC>import model DMsimp_s_spin0
INFO: Change particles name to pass to MG5 convention
Kept definitions of multiparticles l- / j / vl / l+ / p / vl~ unchanged
Defined multiparticle all = g ghg ghg~ u c d s b u~ c~ d~ s~ b~ a gha gha~ ve vm vt e- mu- ve~ vm~ vt~ e+ mu+ t t~ z w+ ghz ghwp ghwm h xr xc y0 w- ghz~ ghwp~ ghwm~ xc~ ta- xd ta+ xd~
MG5_aMC>generate p p > xd xd~ [QCD] /a z w+ w-
------------------------------------------------------------------------
 No Born diagrams found. Now switching to the loop-induced mode.
 Please cite ref. 'arXiv:1507.00020' when using results from this mode.
------------------------------------------------------------------------
1 processes with 2 diagrams generated in 0.715 s
Total: 1 processes with 2 diagrams
MG5_aMC>add process p p > xd xd~ j[QCD] /a z w+ w-
Command "add process p p > xd xd~ j[QCD] /a z w+ w-" interrupted with error:
InvalidCmd : Command not compatible with previous command: Can not combine LO/NLO feature.

Question information

Language:
English Edit question
Status:
Solved
For:
MadGraph5_aMC@NLO Edit question
Assignee:
No assignee Edit question
Solved by:
SooJin Lee
Solved:
2019-11-10
Last query:
2019-11-10
Last reply:
2019-11-09

Hi,

The [QCD] is technically a syntax asking for NLO computation.
The correct syntax for LO loop-induced process is [noborn=QCD]
generate p p > xd xd~ [noborn=QCD] /a z w+ w-

To be user friendly when a user ask [QCD] on a process without any born, then we automatically switch to [noborn=] syntax.
However in your case it crashes before since he believes that you are going to mix LO and NLO process.
So the correct method to do is

generate p p > xd xd~ [noborn=QCD] /a z w+ w-
add process p p > xd xd~ j [noborn=QCD] /a z w+ w-

Cheers,

Olivier

SooJin Lee (bennyben) said : #2

Hi,

The problem still remains with [noborn=QCD].

But when I ran with another version, the problem was solved.

Thank you.

Have a good day!