Problems Computing PDF Uncertainty/Reweight

Asked by Richard Ruiz on 2018-01-16

Hi Folks,

Just updated to 2.6.1 and seem to be having trouble computing PDF uncertainties/PDF re-weighting for an NLO-level process. The problem is confusing since Pythia8 also complains about missing PDF member sets, yet I have no problem downloading new lhapdfs.

For the following process:

import model loop_sm
generate p p > e+ ve [QCD]
output

Here is my output:
MG5_aMC>launch
.
.
set reweight_pdf=True
INFO: modify parameter reweight_pdf of the run_card.dat to [True]
set lhaid=25300
INFO: modify parameter lhaid of the run_card.dat to [25300]
.
.
.
MMHT2014nnlo68cl.tar.gz: 6.9 MB [100.0%]
INFO: MMHT2014nnlo68cl successfully downloaded and stored in /.../HEPTools/lhapdf6//share/LHAPDF
.
.
.
INFO: Generating events
INFO: Idle: 0, Running: 2, Completed: 0 [ current time: 17h15 ]
INFO: Idle: 0, Running: 0, Completed: 2 [ 5.6s ]
INFO: Doing reweight
INFO: Idle: 0, Running: 2, Completed: 0 [ current time: 17h16 ]
INFO: Idle: 0, Running: 1, Completed: 1 [ 13.3s ]
INFO: Idle: 0, Running: 0, Completed: 2 [ 13.5s ]
terminate called after throwing an instance of 'LHAPDF::ReadError'
  what(): Info file not found for PDF set 'MMHT2014nnlo68cl'

Now, rerunning with set reweight_pdf=False gets me to the parton shower. However, Pythia8 crash instead:

INFO: Events generated
reweight -from_cards
decay_events -from_cards
INFO: Preparing MCatNLO run
INFO: Using LHAPDF v6.1.6 interface for PDFs
INFO: Compiling MCatNLO for PYTHIA8...
INFO: ... done
INFO: Showering events...
INFO: (Running in /.../MCatNLO/RUN_PYTHIA8_1)
INFO: Idle: 1, Running: 0, Completed: 0 [ current time: 18h18 ]
/.../MCatNLO/RUN_PYTHIA8_1/shower.sh: line 41: 9418 Aborted ./Pythia8.exe Pythia8.cmd > mcatnlo_run.log 2>&1
mv: cannot stat ‘Pythia8.hep’: No such file or directory
gzip: events.hepmc: No such file or directory
INFO: Idle: 0, Running: 0, Completed: 1 [ 0.62s ]
INFO: Idle: 0, Running: 0, Completed: 0 [ current time: 18h18 ]

Finally, if I try to run Pythia8 by hand, I get the following crash:

$ MCatNLO/RUN_PYTHIA8_1$ ./Pythia8.exe Pythia8.cmd
terminate called after throwing an instance of 'LHAPDF::ReadError'
  what(): Info file not found for PDF set 'MMHT2014nnlo68cl'
Aborted

Suggestions would be much appreciated. Thanks!

Question information

Language:
English Edit question
Status:
Answered
For:
MadGraph5_aMC@NLO Edit question
Assignee:
No assignee Edit question
Last query:
2018-01-16
Last reply:
2018-01-17

Hi Richard,

I actually can not reproduce your error (neither on my mac or on the ucl cluster)

The problem seems to be related to your version of lhapdf so not sure what I can do.
Is it the one that is installed via "install lhapdf6"?

Cheers,

Olivier

> On 16 Jan 2018, at 19:22, Richard Ruiz <email address hidden> wrote:
>
> New question #663136 on MadGraph5_aMC@NLO:
> https://answers.launchpad.net/mg5amcnlo/+question/663136
>
> Hi Folks,
>
> Just updated to 2.6.1 and seem to be having trouble computing PDF uncertainties/PDF re-weighting for an NLO-level process. The problem is confusing since Pythia8 also complains about missing PDF member sets, yet I have no problem downloading new lhapdfs.
>
> For the following process:
>
> import model loop_sm
> generate p p > e+ ve [QCD]
> output
>
> Here is my output:
> MG5_aMC>launch
> .
> .
> set reweight_pdf=True
> INFO: modify parameter reweight_pdf of the run_card.dat to [True]
> set lhaid=25300
> INFO: modify parameter lhaid of the run_card.dat to [25300]
> .
> .
> .
> MMHT2014nnlo68cl.tar.gz: 6.9 MB [100.0%]
> INFO: MMHT2014nnlo68cl successfully downloaded and stored in /.../HEPTools/lhapdf6//share/LHAPDF
> .
> .
> .
> INFO: Generating events
> INFO: Idle: 0, Running: 2, Completed: 0 [ current time: 17h15 ]
> INFO: Idle: 0, Running: 0, Completed: 2 [ 5.6s ]
> INFO: Doing reweight
> INFO: Idle: 0, Running: 2, Completed: 0 [ current time: 17h16 ]
> INFO: Idle: 0, Running: 1, Completed: 1 [ 13.3s ]
> INFO: Idle: 0, Running: 0, Completed: 2 [ 13.5s ]
> terminate called after throwing an instance of 'LHAPDF::ReadError'
> what(): Info file not found for PDF set 'MMHT2014nnlo68cl'
>
>
> Now, rerunning with set reweight_pdf=False gets me to the parton shower. However, Pythia8 crash instead:
>
> INFO: Events generated
> reweight -from_cards
> decay_events -from_cards
> INFO: Preparing MCatNLO run
> INFO: Using LHAPDF v6.1.6 interface for PDFs
> INFO: Compiling MCatNLO for PYTHIA8...
> INFO: ... done
> INFO: Showering events...
> INFO: (Running in /.../MCatNLO/RUN_PYTHIA8_1)
> INFO: Idle: 1, Running: 0, Completed: 0 [ current time: 18h18 ]
> /.../MCatNLO/RUN_PYTHIA8_1/shower.sh: line 41: 9418 Aborted ./Pythia8.exe Pythia8.cmd > mcatnlo_run.log 2>&1
> mv: cannot stat ‘Pythia8.hep’: No such file or directory
> gzip: events.hepmc: No such file or directory
> INFO: Idle: 0, Running: 0, Completed: 1 [ 0.62s ]
> INFO: Idle: 0, Running: 0, Completed: 0 [ current time: 18h18 ]
>
> Finally, if I try to run Pythia8 by hand, I get the following crash:
>
> $ MCatNLO/RUN_PYTHIA8_1$ ./Pythia8.exe Pythia8.cmd
> terminate called after throwing an instance of 'LHAPDF::ReadError'
> what(): Info file not found for PDF set 'MMHT2014nnlo68cl'
> Aborted
>
>
> Suggestions would be much appreciated. Thanks!
>
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

Can you help with this problem?

Provide an answer of your own, or ask Richard Ruiz for more information if necessary.

To post a message you must log in.