Is LHeC at NLO+PS supported?

Asked by Richard Ruiz

Hi Folks,

I am working with MG5_aMC_v2_5_0_beta2 and want to simulate ep collisions at NLO+PS. (I am interested in the changes at the differential level; at the integrated level, this is of course mostly negligible.) Is this scenario supported? I tried the following below, but aMC@NLO quickly crashed. Details are below.

Best,
Richard

MG5_aMC>generate e- p > ve j [QCD]; output Test_ep_vj_NLO; launch

My run card was modified to the following:
0 = lpp1 ! beam 1 type (0 = no PDF)
 1 = lpp2 ! beam 2 type (0 = no PDF)
 60.0 = ebeam1 ! beam 1 energy in GeV
 7000.0 = ebeam2 ! beam 2 energy in GeV

I then got the following:
INFO: Starting run
INFO: Using 4 cores
INFO: Cleaning previous results
INFO: Doing NLO matched to parton shower
WARNING: No integration channels found for contribution P0_emu_ved
WARNING: No integration channels found for contribution P0_emdx_veux
INFO: Setting up grids
INFO: Idle: 0, Running: 0, Completed: 0 [ current time: 10h52 ]
INFO: Computing upper envelope
INFO: Idle: 0, Running: 0, Completed: 0 [ current time: 10h52 ]
Command "launch auto " interrupted with error:
IndexError : list index out of range
Please report this bug on https://bugs.launchpad.net/mg5amcnlo
More information is found in '/.../MG5_aMC_v2_5_0_beta2/Test_ep_vj_NLO/run_01_tag_1_debug.log'.
Please attach this file to your report.
INFO:

The relevant traceback is:
  File "/.../MG5_aMC_v2_5_0_beta2/madgraph/interface/extended_cmd.py", line 1393, in onecmd
    return self.onecmd_orig(line, **opt)
  File "/.../MG5_aMC_v2_5_0_beta2/madgraph/interface/extended_cmd.py", line 1348, in onecmd_orig
    return func(arg, **opt)
  File "/.../MG5_aMC_v2_5_0_beta2/madgraph/interface/amcatnlo_run_interface.py", line 1209, in do_launch
    evt_file = self.run(mode, options)
  File "/.../MG5_aMC_v2_5_0_beta2/madgraph/interface/amcatnlo_run_interface.py", line 1438, in run
    jobs_to_collect,mint_step,mode,mode_dict[mode],fixed_order=False)
  File "/.../MG5_aMC_v2_5_0_beta2/madgraph/interface/amcatnlo_run_interface.py", line 1656, in collect_the_results
    jobs_to_run_new=self.update_jobs_to_run(req_acc,integration_step,jobs_to_run,fixed_order)
  File "/.../MG5_aMC_v2_5_0_beta2/madgraph/interface/amcatnlo_run_interface.py", line 1841, in update_jobs_to_run
    jobs[i]['nevents'] += 1
IndexError: list index out of range

Question information

Language:
English Edit question
Status:
Solved
For:
MadGraph5_aMC@NLO Edit question
Assignee:
marco zaro Edit question
Solved by:
Richard Ruiz
Solved:
Last query:
Last reply:
Revision history for this message
marco zaro (marco-zaro) said :
#1

Dear Richard,
for historical reasons, either 0 or 2 beams have to be hadronic... one is not supported, unfortunately.
I am not aware of any development towards supporting an electron-proton collision
Sorry for this...
best,

Marco

Revision history for this message
Richard Ruiz (rruiz) said :
#2

Hi Marco,

Thanks for the quick response and clarification! Fortunately, LO+PY8 seems to work out of the box, though perhaps with a large event rejection rate (2k/10k rejected).

best,
richard

 *------- PYTHIA Error and Warning Messages Statistics ----------------------------------------------------------*
 | |
 | times message |
 | |
 | 4 Abort from Pythia::next: parton+hadronLevel failed; giving up |
 | 123 Error in BeamRemnants::setOneRemnKinematics: too big beam remnant invariant mass |
 | 1832 Error in ProcessContainer::constructProcess: setting mass failed |
 | 42 Error in Pythia::next: partonLevel failed; try again |
 | 2 Info from SLHAinterface::initSLHA: No MODSEL found, keeping internal SUSY switched off |
 | 2 Info from SLHAinterface::initSLHA: importing MASS entries |
 | 2 Warning in LHAupLHEF::setInitLHEF: corrupt LHEF end tag |
 | 1 Warning in Pythia::check: energy-momentum not quite conserved |
 | 2 Warning in SLHAinterface::initSLHA: ignoring DECAY tables |
 | 2 Warning in SLHAinterface::initSLHA: ignoring MASS entries |
 | 2 Warning in SLHAinterface::initSLHA: ignoring empty DECAY tables |
 | 300 Warning in SpaceShower::branch: used up beam momentum; retrying parton level |
 | 17 Warning in SpaceShower::pT2nextQCD: weight above unity |
 | |
 *------- End PYTHIA Error and Warning Messages Statistics ------------------------------------------------------*