Error while showering shower my events with the NLO QCD

Hi,

Obviously we are not expert in all the various way pythia8 can crash.
(And pythia8 author are not expert in the way we do interface our code to theirs).
So this is not always easy to understand what is going on.

In principle, you should have a log file within the following directory:
> /home/sourav.bera/MG5_aMC_v2_9_7/trial_SB/MCatNLO/RUN_PYTHIA8_1

With infiormation that might indicate what the issue is.

Cheers,

Olivier

> On 19 Dec 2023, at 08:45, Sourav <email address hidden> wrote:
>
> New question #708751 on MadGraph5_aMC@NLO:
> https://answers.launchpad.net/mg5amcnlo/+question/708751
>
> Dear experts,
>
> I am getting the following error when trying to shower my events with the NLO QCD option. The showering goes through perfectly when I am using an LO sample.
> ---------------------------------------------------------------------------------------------------------------------------------------------------------------
> INFO: Compiling MCatNLO for PYTHIA8...
>
> INFO: ... done
>
> INFO: Showering events...
>
> INFO: (Running in /home/sourav.bera/MG5_aMC_v2_9_7/trial_SB/MCatNLO/RUN_PYTHIA8_1)
>
> INFO: Idle: 1, Running: 0, Completed: 0 [ current time: 12h28 ]
>
> 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 [ 0.1s ]
>
> INFO: Idle: 0, Running: 0, Completed: 0 [ current time: 12h28 ]
>
> Error detected in "launch auto "
>
> write debug file /home/sourav.bera/MG5_aMC_v2_9_7/trial_SB/run_01_decayed_1_tag_1_debug.log
>
> If you need help with this issue please contact us on https://answers.launchpad.net/mg5amcnlo
>
> str : No file has been generated, an error occurred. More information in /home/sourav.bera/MG5_aMC_v2_9_7/amcatnlo_run.log
>
> quit
>
> INFO: gzipping output file: events.lhe
>
> ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
>
>
> Here are some of my observations.
>
> 1. In my older machine, lhapdf6 version 6.3.0 was installed and everything was working fine.
>
> 2. In my present machine, lhapdf6 version 6.5.3 is getting installed and I am unable to get showered events (please see error above).
>
> 3. I am using MG5 version 2.9.7. Is it necessary to change the MG5 version? The old version was working fine.
>
> Could you please let me know what might be going on and how I can sort this problem out?
>
> Thanks.
>
> Regards,
>
> Sourav.
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

Hi, thanks for the comment.
The MCatNLO logfile shows the following error :

 ------------------------------------------------------------------------------------
 PYTHIA Info from SLHAinterface::initSLHA: No MODSEL found, keeping internal SUSY switched off
 PYTHIA Warning in SLHAinterface::initSLHA: ignoring QNUMBERS for id = 82 (already exists)
 PYTHIA Warning in SLHAinterface::initSLHA: ignoring MASS entries for id = {1,2,3,4,5,11,12,13,14,15,16,21,22,23,24} (m0 < SLHA:minMassSM)
 PYTHIA Warning in SLHAinterface::initSLHA: ignoring DECAY tables for id = {1,2,3,4,5,11,12,13,14,15,16,21,22,23,24} (m0 < SLHA:minMassSM)
 PYTHIA Warning in SLHAinterface::initSLHA: ignoring empty DECAY tables for id = {6,25} (total width provided but no Branching Ratios)
 PYTHIA Error in LHAGrid1::init: did not find data file
 PYTHIA Error in Pythia::init: could not set up PDF for beam A
 PYTHIA Abort from Pythia::init: PDF initialization failed
Error: could not initialise Pythia
-----------------------------------------------------------------------------------------
Additionally, lhapdf6_py3 version 6.5.3 was installed successfully but the logfile shows the following error :

touch fix-out-of-source
CC="g++" CXX="g++" CFLAGS="-g -O2" CXXFLAGS="-static-libstdc++ -std=c++11 " CPPFLAGS="-I/home/sourav.bera/MG5_aMC_v2_9_7/HEPTools/lhapdf6_py3/include -I." LHAPDF_LOCAL=1 /home/sourav.bera/anaconda3/bin/python3 build.py
No libpython found in expected location None, exiting
make[2]: *** [Makefile:501: all-local] Error 1
make[2]: Leaving directory '/tmp/tmpzrx7r_xu/LHAPDF-6.5.3/wrappers/python'
make[1]: *** [Makefile:385: all-recursive] Error 1
make[1]: Leaving directory '/tmp/tmpzrx7r_xu/LHAPDF-6.5.3/wrappers'
make: *** [Makefile:522: all-recursive] Error 1
 Install LHAPDF6
Making install in src

Could you please let me know how to sort out this problem ? Could it be a problem due to version of python (3.11.5) ?

Thanks,
Regards,
Sourav.

So your issue seems to be related to lhapdf.
Since pythia8 seems to not be able to link correctly to lhapdf to setup up itself.

Since it was working before my advise is to use the same old version of lhapdf that you were using before
and then recompile pythia8. It is not clear to me what 2.9.7 supports in term of lhapdf/pythia8 combination. The "install" command is checked/maintained only with the latest LTS (currently 2.9.18) and latest development version (currently 3.5.2) but provide --as is-- on any older version. So if you want to keep older version, you likely need to avoid to use the install command.

Now the question, is what is the exact status of the lhapdf installation?
Do you just miss the python interface? or do you miss the full code (do you have a file lhapdf-config (likely in the bin directory)? I would not be surprised that this is your issue.

Cheers,

Olivier

> On 19 Dec 2023, at 11:20, Sourav <email address hidden> wrote:
>
> Question #708751 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/708751
>
> Sourav posted a new comment:
> Hi, thanks for the comment.
> The MCatNLO logfile shows the following error :
>
> ------------------------------------------------------------------------------------
> PYTHIA Info from SLHAinterface::initSLHA: No MODSEL found, keeping internal SUSY switched off
> PYTHIA Warning in SLHAinterface::initSLHA: ignoring QNUMBERS for id = 82 (already exists)
> PYTHIA Warning in SLHAinterface::initSLHA: ignoring MASS entries for id = {1,2,3,4,5,11,12,13,14,15,16,21,22,23,24} (m0 < SLHA:minMassSM)
> PYTHIA Warning in SLHAinterface::initSLHA: ignoring DECAY tables for id = {1,2,3,4,5,11,12,13,14,15,16,21,22,23,24} (m0 < SLHA:minMassSM)
> PYTHIA Warning in SLHAinterface::initSLHA: ignoring empty DECAY tables for id = {6,25} (total width provided but no Branching Ratios)
> PYTHIA Error in LHAGrid1::init: did not find data file
> PYTHIA Error in Pythia::init: could not set up PDF for beam A
> PYTHIA Abort from Pythia::init: PDF initialization failed
> Error: could not initialise Pythia
> -----------------------------------------------------------------------------------------
> Additionally, lhapdf6_py3 version 6.5.3 was installed successfully but the logfile shows the following error :
>
> touch fix-out-of-source
> CC="g++" CXX="g++" CFLAGS="-g -O2" CXXFLAGS="-static-libstdc++ -std=c++11 " CPPFLAGS="-I/home/sourav.bera/MG5_aMC_v2_9_7/HEPTools/lhapdf6_py3/include -I." LHAPDF_LOCAL=1 /home/sourav.bera/anaconda3/bin/python3 build.py
> No libpython found in expected location None, exiting
> make[2]: *** [Makefile:501: all-local] Error 1
> make[2]: Leaving directory '/tmp/tmpzrx7r_xu/LHAPDF-6.5.3/wrappers/python'
> make[1]: *** [Makefile:385: all-recursive] Error 1
> make[1]: Leaving directory '/tmp/tmpzrx7r_xu/LHAPDF-6.5.3/wrappers'
> make: *** [Makefile:522: all-recursive] Error 1
> Install LHAPDF6
> Making install in src
>
> Could you please let me know how to sort out this problem ? Could it be
> a problem due to version of python (3.11.5) ?
>
> Thanks,
> Regards,
> Sourav.
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.