run card not showing all the options

Asked by Shubhani Jain on 2021-02-02

Hi

I am generating events for g g > h2 > h1 h1 [QCD] and then decaying h1 > b b~ using madspin.
I get a warning
WARNING: Channel G1//scratch/sj1n19/MG5/MG5_aMC_v2_7_2/check/SubProcesses/P0_gg_h1h1 has a very low efficiency of unweighting. Might not be possible to reach target.

But it does continue to run and outputs hepmc file. Is this alright or will it change the events?

Also for some reason, the option to apply cuts in run_card.dat doesn't display all the options. For example, I don't get any option to put pt_j,eta_j, and many more. I am attaching two madgraph run_card one from version 2_7_2 and the other being from an older version. It would be helpful to know from where I can get these options as well.

https://www.dropbox.com/sh/l7r4vf12ybipp1j/AABrRhRpwWuEckz-AZVcw4G-a?dl=0

Thanks
Shubhani

Question information

Language:
English Edit question
Status:
Solved
For:
MadGraph5_aMC@NLO Edit question
Assignee:
No assignee Edit question
Solved by:
Olivier Mattelaer
Solved:
2021-02-02
Last query:
2021-02-02
Last reply:
2021-02-02

Hi,

> But it does continue to run and outputs hepmc file. Is this alright or will it change the events?

This is an "early" warning that this might fail to reach the targeted number of events.
So this is just an indication that the running time might be very long and that it might fail to generate the requested number of events.
If you are fine to wait and that you reach the expected number of events it is likely that everything is fine
(but you should obviously be a bit more cautious than usual with the validation of the results)

> Also for some reason, the option to apply cuts in run_card.dat doesn't display all the options.

Yes the run_card was confusing for a lot of people because it was much too long and was containing a lot of useless entry.
So we have reduce the size of the run_card such that it is much shorter and contains only relevant information.

> For example, I don't get any option to put pt_j,eta_j, and many more.

This is a good example of useless information for your process, you do not have any jet in the final state and therefore setting a value for those cuts is irrelevant for this process.Therefore we do not display it by default in the run_card.
(you can specify the line obviously and it will work and not complain but this will not impact anything)

> It would be helpful to know from where I can get these options as well.

So we do have a lot of parameter in the run_card.
Only a few of them are present by default for any process (like nevents, pdf, energy,...)
Quite a lot of them are always hidden (mainly advanced parameter for tuning job submission, debugging,...)

The rest depend of the process that you generate.

Note that for parameter displayed in the run_card, the value set in the run_card can also depend of the process
for example e+ e+ > j j will have the beam type set to 0 (no PDF) and the energy of the beam will be 500GeV per beam.
On the other hand p p > j j will have beam set to 1 (proton PDF) and 6.5 TeV per beam by default.

Some "block" of parameter can be made visible via the "update" command.
using the auto-completion show you the full list of possible arguments:

> Do you want to edit a card (press enter to bypass editing)?
> /------------------------------------------------------------\
> | 1. param : param_card.dat |
> | 2. run : run_card.dat |
> | 3. plot : plot_card.dat |
> \------------------------------------------------------------/
> you can also
> - enter the path to a valid card or banner.
> - use the 'set' command to modify a parameter directly.
> The set option works only for param_card and run_card.
> Type 'help set' for more information on this command.
> - call an external program (ASperGE/MadWidth/...).
> Type 'help' for the list of available command
> [0, done, 1, param, 2, run, 3, plot, enter path]
> >update
> beam_pol ckkw dependent ecut frame ion_pdf missing mlm psoptim syscalc to_full to_slha1 to_slha2

and typing "help update" gives you information on the special parameter --not related to the run_card--.

> INFO: *** HELP MESSAGE ***
> syntax: update dependent: Change the mass/width of particles which are not free parameter for the model.
> update missing: add to the current param_card missing blocks/parameters.
> update to_slha1: pass SLHA2 card to SLHA1 convention. (beta)
> update to_slha2: pass SLHA1 card to SLHA2 convention. (beta)
> update to_full [run_card]
> update XXX [where XXX correspond to a hidden block of the run_card]
>
> INFO: *** END HELP ***

For example you can do
"update ion_pdf"
if you want to add in the run_card all the options related to rescaling one PDF to another hadron type.
You can also do
'update ecut"
to add energy cuts in the center of mass but those are quite bad to use for LHC physics (since people always miss the fact that those are not cut in the lab frame)
Note that the "psoptim" block is new since 2.9.0

To have all the possible run_card parameter, you can use
"update to_full"
in that case you will have all possible parameter included in the run_card.

If you think that an option should be visible by default for a given process, this is an interesting feedback obviously.

Cheers,

Olivier

Shubhani Jain (s2697661) said : #2

Hi Olivier

Thanks for explaining the run card options. I will check this out.

Regards
Shubhani

Shubhani Jain (s2697661) said : #3

Thanks Olivier Mattelaer, that solved my question.