Problem with generation gq @NLO

Asked by Mar on 2018-01-09

Hi, I am working on the process gb > t w- [QCD]. I want to generate events for it, but I've got the message "Error detected in "launch auto "
write debug file blabla/run_01_tag_1_debug.log
If you need help with this issue please contact us on
aMCatNLOError : An error occurred during the collection of results.
 Please check the .log files inside the directories which failed:"

The whole production is

MG5_aMC>define p = p b b~
Defined multiparticle p = g u c d s u~ c~ d~ s~ b b~
MG5_aMC>generate g b > t w- [QCD]
The current model sm does not allow to generate loop corrections of type ['QCD'].
MG5_aMC now loads 'loop_sm'.
 import model loop_sm
INFO: Restrict model loop_sm with file models/loop_sm/restrict_default.dat .
INFO: Run "set stdout_level DEBUG" before import for more information.
INFO: Change particles name to pass to MG5 convention
Pass the definition of 'j' and 'p' to 4 flavour scheme.
Kept definitions of multiparticles l- / vl / l+ / vl~ unchanged
Defined multiparticle all = g gh gh~ d u s c d~ u~ s~ c~ a ve vm vt e- mu- ve~ vm~ vt~ e+ mu+ b t b~ t~ z w+ h w- ta- ta+
WARNING: Process: g b > t w- WEIGHTED=3 [ all = QCD ] can have real emission processes which are not finite.
To avoid this, please use multiparticles when generating the process and be sure to include all the following particles in the multiparticle definition:
 g, c, s, u, d, d~, u~, s~, c~
INFO: Generating FKS-subtracted matrix elements for born process: g b > t w- [ all = QCD ] (1 / 1)
INFO: Generating virtual matrix elements using MadLoop:
INFO: Generating virtual matrix element with MadLoop for process: g b > w- t QCD<=1 QED<=1 [ all = QCD ] (1 / 1)
INFO: Generated 1 subprocesses with 32 real emission diagrams, 2 born diagrams and 11 virtual diagrams
MG5_aMC>output pruebatwb5f
INFO: Writing out the aMC@NLO code, using optimized Loops
INFO: initialize a new directory: pruebatwb4f
INFO: remove old information in pruebatwb4f
INFO: Generating real emission matrix-elements...
INFO: Generating Helas calls for FKS process: g b > w- t [ all = QCD ] (1 / 1)
INFO: Processing color information for process: g b > w- t [ all = QCD ]
INFO: ... Done
INFO: Writing files in P0_gb_wmt (1 / 1)
INFO: Creating files in directory V0_gb_wmt
ALOHA: aloha creates FFV1 set of routines with options: L2,P0
INFO: Computing diagram color coefficients
INFO: Drawing loop Feynman diagrams for Process: g b > w- t QCD<=1 QED<=1 [ all = QCD ]
INFO: Generating born Feynman diagrams for Process: g b > w- t QCD<=1 QED<=1 [ all = QCD ]
History written to /home/mariel/MG5_aMC_v2_6_0/pruebatwb4f/Cards/proc_card_mg5.dat
ALOHA: aloha creates FFV2 routines
ALOHA: aloha creates R2_QQ_2 routines
ALOHA: aloha creates R2_QQ_1 routines
ALOHA: aloha creates FFV1 routines
ALOHA: aloha creates VVV1 set of routines with options: P0
ALOHA: aloha creates R2_QQ_1_R2_QQ_2 routines
save configuration file to /home/mariel/MG5_aMC_v2_6_0/pruebatwb4f/Cards/amcatnlo_configuration.txt
INFO: The value for lhapdf in the current configuration does not correspond to a valid executable.
Please set it correctly either in input/mg5_configuration or with "set lhapdf /path/to/lhapdf-config" and regenrate the process.
To avoid regeneration, edit the /home/mariel/MG5_aMC_v2_6_0/pruebatwb4f/Cards/amcatnlo_configuration.txt file.
Note that you can still compile and run aMC@NLO with the built-in PDFs

INFO: Use Fortran compiler gfortran
INFO: Use c++ compiler g++
INFO: Generate jpeg diagrams
INFO: Generate web pages

INFO: ************************************************************
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* a M C @ N L O *
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* VERSION 2.6.0 2017-08-16 *
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* The MadGraph5_aMC@NLO Development Team - Find us at *
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* Type 'help' for in-line help. *
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INFO: load configuration from /home/mariel/.mg5/mg5_configuration.txt
INFO: load configuration from /home/mariel/MG5_aMC_v2_6_0/pruebatwb4f/Cards/amcatnlo_configuration.txt
INFO: load configuration from /home/mariel/MG5_aMC_v2_6_0/input/mg5_configuration.txt
INFO: load configuration from /home/mariel/MG5_aMC_v2_6_0/pruebatwb4f/Cards/amcatnlo_configuration.txt
Using default text editor "vi". Set another one in ./input/mg5_configuration.txt
launch auto
The following switches determine which operations are executed:
 1 Perturbative order of the calculation: order=NLO
 2 Fixed order (no event generation and no MC@[N]LO matching): fixed_order=OFF
 3 Shower the generated events: shower=ON
 4 Decay particles with the MadSpin module: madspin=OFF
 5 Add weights to the events based on changing model parameters: reweight=OFF
 6 Run MadAnalysis5 on the events generated: madanalysis5=Not installed
  Either type the switch number (1 to 6) to change its default setting,
  or set any switch explicitly (e.g. type 'order=LO' at the prompt)
  Type '0', 'auto', 'done' or just press enter when you are done.
 [0, 1, 2, 3, 4, 5, auto, done, order=LO, ... ][60s to answer]
INFO: will run in mode: aMC@NLO
Do you want to edit a card (press enter to bypass editing)?
| 1. param : param_card.dat |
| 2. run : run_card.dat |
| 3. shower : shower_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, shower, enter path][90s to answer]
INFO: Update the dependent parameter of the param_card.dat
INFO: Starting run
Unhandled exception in thread started by <function call at 0x7f254fb4a758>
Traceback (most recent call last):
  File "/usr/lib64/python2.7/", line 168, in call
    return Popen(*popenargs, **kwargs).wait()
  File "/usr/lib64/python2.7/", line 390, in __init__
    errread, errwrite)
  File "/usr/lib64/python2.7/", line 1024, in _execute_child
    raise child_exception
OSError: [Errno 2] No such file or directory
INFO: Compiling the code
INFO: For gauge cancellation, the width of 't' has been set to zero.
INFO: Using built-in libraries for PDFs
INFO: Compiling source...
INFO: ...done, continuing with P* directories
INFO: Compiling directories...
INFO: Compiling on 4 cores
INFO: Compiling P0_gb_wmt...
STOP pz is not conserved (flag:CT692)
INFO: P0_gb_wmt done.
INFO: Checking test output:
INFO: P0_gb_wmt
INFO: Result for test_ME:
INFO: Passed.
INFO: Result for test_MC:
INFO: Passed.
INFO: Result for check_poles:
WARNING: 0 points have been tried
INFO: Starting run
INFO: Using 4 cores
INFO: Cleaning previous results
INFO: Doing NLO matched to parton shower
INFO: Setting up grids
INFO: Idle: 0, Running: 0, Completed: 2 [ current time: 15h34 ]
Error detected in "launch auto "
write debug file /home/mariel/MG5_aMC_v2_6_0/pruebatwb4f/run_01_tag_1_debug.log
If you need help with this issue please contact us on
aMCatNLOError : An error occurred during the collection of results.
 Please check the .log files inside the directories which failed:

If I work on 4 flavors scheme I get the same error. What can I do?

Thank you!


Question information

English Edit question
MadGraph5_aMC@NLO Edit question
Rikkert Frederix Edit question
Solved by:
Rikkert Frederix
Last query:
Last reply:
Best Rikkert Frederix (frederix) said : #1

Dear Mariel,

The model you are using seems to have a massive b quark. Therefore you cannot have initial state b quarks at NLO. Moreover, it is not consistent to specify quarks and gluons at NLO: they are not IR-safe objects and therefore NLO corrections to then are not well-defined. Rather, what should work is

import model loop_sm-no_b_mass
generate p p > t w- [QCD]

However, remember that this process includes LO top pair resonant contributions at the NLO real-emission level. Hence, you'll need to be careful with the interpretation of the results.


Mar (septembris-forest) said : #2

OK, I see. Thank you!



Mar (septembris-forest) said : #3

Thanks Rikkert Frederix, that solved my question.