MadGraph5_aMC@NLO

Incorrect cross sections

Asked by Gerardo

Hi,

I am generating gluon fusion to higgs events and the output cross section is incorrect. I am running the events with a CM energy of 13TeV (both beams have energy 6500 GeV) and using the model loop_sm. I expect a cross section of around 44 pb at this energy for this process but MG calculates around 15 pb. Ive tried removing the cuts in the param_card but this does not resolve the issue. Is there something I am doing wrong?

Here is the code:

************************************************************
* *
* W E L C O M E to *
* M A D G R A P H 5 _ a M C @ N L O *
* *
* *
* * * *
* * * * * *
* * * * * 5 * * * * *
* * * * * *
* * * *
* *
* VERSION 2.3.0 2015-07-01 *
* *
* The MadGraph5_aMC@NLO Development Team - Find us at *
* https://server06.fynu.ucl.ac.be/projects/madgraph *
* and *
* http://amcatnlo.web.cern.ch/amcatnlo/ *
* *
* Type 'help' for in-line help. *
* Type 'tutorial' to learn how MG5 works *
* Type 'tutorial aMCatNLO' to learn how aMC@NLO works *
* Type 'tutorial MadLoop' to learn how MadLoop works *
* *
************************************************************
load MG5 configuration from input/mg5_configuration.txt
set fastjet to /home/jerry/fastjet-3.1.3/fastjet-config
set lhapdf to lhapdf-config
Using default text editor "vi". Set another one in ./input/mg5_configuration.txt
Using default eps viewer "evince". Set another one in ./input/mg5_configuration.txt
Using default web browser "firefox". Set another one in ./input/mg5_configuration.txt
Loading default model: sm
INFO: Restrict model sm with file models/sm/restrict_default.dat .
INFO: Run "set stdout_level DEBUG" before import for more information.
INFO: Change particles name to pass to MG5 convention
Defined multiparticle p = g u c d s u~ c~ d~ s~
Defined multiparticle j = g u c d s u~ c~ d~ s~
Defined multiparticle l+ = e+ mu+
Defined multiparticle l- = e- mu-
Defined multiparticle vl = ve vm vt
Defined multiparticle vl~ = ve~ vm~ vt~
Defined multiparticle all = g u c d s u~ c~ d~ s~ a ve vm vt e- mu- ve~ vm~ vt~ e+ mu+ t b t~ b~ z w+ h w- ta- ta+
MG5_aMC>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
Kept definitions of multiparticles l- / j / vl / l+ / p / 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+
MG5_aMC>generate g g > h [QCD]
------------------------------------------------------------------------
 No Born diagrams found. Now switching to the loop-induced mode.
 Please cite ref. 'arXiv:1507.00020' when using results from this mode.
------------------------------------------------------------------------
1 processes with 4 diagrams generated in 0.260 s
Total: 1 processes with 4 diagrams
MG5_aMC>output TESTEE
INFO: directory /home/jerry/MG5_aMC_v2_3_0/TESTEE already exists.
If you continue this directory will be deleted and replaced.
Do you want to continue? [y, n][60s to answer]
>y
INFO: initialize a new directory: TESTEE
INFO: remove old information in TESTEE
INFO: Organizing processes into subprocess groups
INFO: Generating Helas calls for process: g g > h WEIGHTED=4 [ noborn = QCD ]
INFO: Processing color information for loop process: g g > h [ noborn = QCD ]
INFO: Creating color matrix loop process: g g > h WEIGHTED=4 [ noborn = QCD ]
INFO: Creating files in directory /home/jerry/MG5_aMC_v2_3_0/TESTEE/SubProcesses/PV0_0_1_gg_h
ALOHA: aloha creates FFV1 set of routines with options: L1
INFO: Computing diagram color coefficients
INFO: Drawing loop Feynman diagrams for Process: g g > h WEIGHTED=4 [ noborn = QCD ]
INFO: Creating files in directory P0_gg_h
INFO: Generating Feynman diagrams for Process: g g > h WEIGHTED=4 [ noborn = QCD ]
INFO: Finding symmetric diagrams for subprocess group gg_h
History written to /home/jerry/MG5_aMC_v2_3_0/TESTEE/Cards/proc_card_mg5.dat
Generated helas calls for 1 subprocesses (4 diagrams) in 0.081 s
Export UFO model to MG4 format
ALOHA: aloha creates FFS1 set of routines with options: L2
ALOHA: aloha creates VVS1 routines
save configuration file to /home/jerry/MG5_aMC_v2_3_0/TESTEE/Cards/me5_configuration.txt
INFO: Use Fortran compiler gfortran
INFO: Generate jpeg diagrams
INFO: Generate web pages
Output to directory /home/jerry/MG5_aMC_v2_3_0/TESTEE done.
Type "launch" to generate events from this process, or see
/home/jerry/MG5_aMC_v2_3_0/TESTEE/README
Run "open index.html" to see more information about this process.
MG5_aMC>launch
************************************************************
* *
* W E L C O M E to *
* M A D G R A P H 5 _ a M C @ N L O *
* M A D E V E N T *
* *
* * * *
* * * * * *
* * * * * 5 * * * * *
* * * * * *
* * * *
* *
* VERSION 2.3.0 2015-07-01 *
* *
* The MadGraph5_aMC@NLO Development Team - Find us at *
* https://server06.fynu.ucl.ac.be/projects/madgraph *
* *
* Type 'help' for in-line help. *
* *
************************************************************
INFO: load configuration from /home/jerry/MG5_aMC_v2_3_0/TESTEE/Cards/me5_configuration.txt
INFO: load configuration from /home/jerry/MG5_aMC_v2_3_0/input/mg5_configuration.txt
INFO: load configuration from /home/jerry/MG5_aMC_v2_3_0/TESTEE/Cards/me5_configuration.txt
Using default text editor "vi". Set another one in ./input/mg5_configuration.txt
No valid SysCalc path found
generate_events run_01
The following switches determine which programs are run:
 1 Run the pythia shower/hadronization: pythia=OFF
 2 Run PGS as detector simulator: pgs=OFF
 3 Run Delphes as detector simulator: delphes=OFF
 4 Decay particles with the MadSpin module: madspin=OFF
 5 Add weight to events based on coupling parameters: reweight=OFF
  Either type the switch number (1 to 5) to change its default setting,
  or set any switch explicitly (e.g. type 'madspin=ON' at the prompt)
  Type '0', 'auto', 'done' or just press enter when you are done.
 [0, 1, 2, 3, 4, 5, auto, done, pythia=ON, ... ][60s to answer]
>
Do you want to edit a card (press enter to bypass editing)?
  1 / param : param_card.dat
  2 / run : run_card.dat
  3 / MadLoopParams : MadLoopParams.dat
  9 / 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, MadLoopParams, 9, enter path, ... ][60s to answer]
>2
open /home/jerry/MG5_aMC_v2_3_0/TESTEE/Cards/run_card.dat
Do you want to edit a card (press enter to bypass editing)?
  1 / param : param_card.dat
  2 / run : run_card.dat
  3 / MadLoopParams : MadLoopParams.dat
  9 / 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, MadLoopParams, 9, enter path, ... ]
>
Generating 100 events with run name run_01
survey run_01
INFO: compile directory

(process:7742): GLib-CRITICAL **: g_slice_set_config: assertion 'sys_page_size == 0' failed
initMadLoop -r -f
Initializing MadLoop loop-induced matrix elements (this can take some time)...
MadLoop initialization finished.
compile Source Directory
Using random number seed offset = 21
INFO: Running Survey
Creating Jobs
Working on SubProcesses
INFO: P0_gg_h
INFO: Idle: 1, Running: 1, Completed: 0 [ current time: 03h08 ]
INFO: Idle: 1, Running: 0, Completed: 2 [ 2.5s ]
INFO: P0_gg_h/G1 is at 16 +- 0.267 pb. Now submitting iteration #2.
INFO: Idle: 0, Running: 1, Completed: 4 [ 7.5s ]
INFO: P0_gg_h/G1 is at 15.85 +- 0.05 pb. Now submitting iteration #3.
INFO: Idle: 0, Running: 1, Completed: 7 [ 16.9s ]
INFO: Survey finished for P0_gg_h/G1 at 15.72 +- 0.0483 pb
INFO: Idle: 0, Running: 0, Completed: 9 [ 17s ]
INFO: End survey
refine 100
Creating Jobs
INFO: Refine results to 100
INFO: Generating 100.0 unweigthed events.
INFO: Effective Luminosity 7.25144710896 pb^-1
INFO: need to improve 0 channels
Current estimate of cross-section: 15.721 +- 0.048287
INFO: Idle: 0, Running: 0, Completed: 0 [ current time: 03h08 ]
INFO: Combining runs
INFO: finish refine
refine 100
Creating Jobs
INFO: Refine results to 100
INFO: Generating 100.0 unweigthed events.
INFO: Effective Luminosity 7.25144710896 pb^-1
INFO: need to improve 0 channels
Current estimate of cross-section: 15.721 +- 0.048287
INFO: Idle: 0, Running: 0, Completed: 0 [ current time: 03h08 ]
INFO: Combining runs
INFO: finish refine
combine_events
INFO: Combining Events

  === Results Summary for run: run_01 tag: tag_1 ===

     Cumulative sequential time for this run: 33 seconds
     Cross-section : 15.72 +- 0.04829 pb
     Nb of events : 100

running syscalc on mode parton
INFO: Creating Plots for parton level
INFO: Plots for parton level generated, see /home/jerry/MG5_aMC_v2_3_0/TESTEE/HTML/run_01/plots_parton.html
INFO: End Plots for parton level
store_events
INFO: Storing parton level results
INFO: End Parton
reweight -from_cards
decay_events -from_cards
quit
INFO:

INFO:

--Gerardo

Question information

Language:
English Edit question
Status:
Solved
For:
MadGraph5_aMC@NLO Edit question
Assignee:
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Solved by:
Olivier Mattelaer
Solved:
Last query:
Last reply:
Revision history for this message
Best Olivier Mattelaer (olivier-mattelaer) said : 		#1

Hi,

The number returned by MG is the correct one, you can read 1507.00020
for validation of the number that you get. Note that the number returned is the leading order (which is one loop) contribution.
The number of 44pb is the number returned by the N^3LO computation with the b taken as massless and the top to be infinitively heavy (See 1503.06056).

This process is know to have extremely large K-factor (See 1503.06056) and that same paper (fig 2) shows that indeed the LO contribution is ~ 15 pb.

Cheers,

Olivier

On 07 Aug 2015, at 11:12, Gerardo <email address hidden> wrote:

> New question #270096 on MadGraph5_aMC@NLO:
> https://answers.launchpad.net/mg5amcnlo/+question/270096
>
> Hi,
>
> I am generating gluon fusion to higgs events and the output cross section is incorrect. I am running the events with a CM energy of 13TeV (both beams have energy 6500 GeV) and using the model loop_sm. I expect a cross section of around 44 pb at this energy for this process but MG calculates around 15 pb. Ive tried removing the cuts in the param_card but this does not resolve the issue. Is there something I am doing wrong?
>
> Here is the code:
>
> ************************************************************
> * *
> * W E L C O M E to *
> * M A D G R A P H 5 _ a M C @ N L O *
> * *
> * *
> * * * *
> * * * * * *
> * * * * * 5 * * * * *
> * * * * * *
> * * * *
> * *
> * VERSION 2.3.0 2015-07-01 *
> * *
> * The MadGraph5_aMC@NLO Development Team - Find us at *
> * https://server06.fynu.ucl.ac.be/projects/madgraph *
> * and *
> * http://amcatnlo.web.cern.ch/amcatnlo/ *
> * *
> * Type 'help' for in-line help. *
> * Type 'tutorial' to learn how MG5 works *
> * Type 'tutorial aMCatNLO' to learn how aMC@NLO works *
> * Type 'tutorial MadLoop' to learn how MadLoop works *
> * *
> ************************************************************
> load MG5 configuration from input/mg5_configuration.txt
> set fastjet to /home/jerry/fastjet-3.1.3/fastjet-config
> set lhapdf to lhapdf-config
> Using default text editor "vi". Set another one in ./input/mg5_configuration.txt
> Using default eps viewer "evince". Set another one in ./input/mg5_configuration.txt
> Using default web browser "firefox". Set another one in ./input/mg5_configuration.txt
> Loading default model: sm
> INFO: Restrict model sm with file models/sm/restrict_default.dat .
> INFO: Run "set stdout_level DEBUG" before import for more information.
> INFO: Change particles name to pass to MG5 convention
> Defined multiparticle p = g u c d s u~ c~ d~ s~
> Defined multiparticle j = g u c d s u~ c~ d~ s~
> Defined multiparticle l+ = e+ mu+
> Defined multiparticle l- = e- mu-
> Defined multiparticle vl = ve vm vt
> Defined multiparticle vl~ = ve~ vm~ vt~
> Defined multiparticle all = g u c d s u~ c~ d~ s~ a ve vm vt e- mu- ve~ vm~ vt~ e+ mu+ t b t~ b~ z w+ h w- ta- ta+
> MG5_aMC>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
> Kept definitions of multiparticles l- / j / vl / l+ / p / 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+
> MG5_aMC>generate g g > h [QCD]
> ------------------------------------------------------------------------
> No Born diagrams found. Now switching to the loop-induced mode.
> Please cite ref. 'arXiv:1507.00020' when using results from this mode.
> ------------------------------------------------------------------------
> 1 processes with 4 diagrams generated in 0.260 s
> Total: 1 processes with 4 diagrams
> MG5_aMC>output TESTEE
> INFO: directory /home/jerry/MG5_aMC_v2_3_0/TESTEE already exists.
> If you continue this directory will be deleted and replaced.
> Do you want to continue? [y, n][60s to answer]
>> y
> INFO: initialize a new directory: TESTEE
> INFO: remove old information in TESTEE
> INFO: Organizing processes into subprocess groups
> INFO: Generating Helas calls for process: g g > h WEIGHTED=4 [ noborn = QCD ]
> INFO: Processing color information for loop process: g g > h [ noborn = QCD ]
> INFO: Creating color matrix loop process: g g > h WEIGHTED=4 [ noborn = QCD ]
> INFO: Creating files in directory /home/jerry/MG5_aMC_v2_3_0/TESTEE/SubProcesses/PV0_0_1_gg_h
> ALOHA: aloha creates FFV1 set of routines with options: L1
> INFO: Computing diagram color coefficients
> INFO: Drawing loop Feynman diagrams for Process: g g > h WEIGHTED=4 [ noborn = QCD ]
> INFO: Creating files in directory P0_gg_h
> INFO: Generating Feynman diagrams for Process: g g > h WEIGHTED=4 [ noborn = QCD ]
> INFO: Finding symmetric diagrams for subprocess group gg_h
> History written to /home/jerry/MG5_aMC_v2_3_0/TESTEE/Cards/proc_card_mg5.dat
> Generated helas calls for 1 subprocesses (4 diagrams) in 0.081 s
> Export UFO model to MG4 format
> ALOHA: aloha creates FFS1 set of routines with options: L2
> ALOHA: aloha creates VVS1 routines
> save configuration file to /home/jerry/MG5_aMC_v2_3_0/TESTEE/Cards/me5_configuration.txt
> INFO: Use Fortran compiler gfortran
> INFO: Generate jpeg diagrams
> INFO: Generate web pages
> Output to directory /home/jerry/MG5_aMC_v2_3_0/TESTEE done.
> Type "launch" to generate events from this process, or see
> /home/jerry/MG5_aMC_v2_3_0/TESTEE/README
> Run "open index.html" to see more information about this process.
> MG5_aMC>launch
> ************************************************************
> * *
> * W E L C O M E to *
> * M A D G R A P H 5 _ a M C @ N L O *
> * M A D E V E N T *
> * *
> * * * *
> * * * * * *
> * * * * * 5 * * * * *
> * * * * * *
> * * * *
> * *
> * VERSION 2.3.0 2015-07-01 *
> * *
> * The MadGraph5_aMC@NLO Development Team - Find us at *
> * https://server06.fynu.ucl.ac.be/projects/madgraph *
> * *
> * Type 'help' for in-line help. *
> * *
> ************************************************************
> INFO: load configuration from /home/jerry/MG5_aMC_v2_3_0/TESTEE/Cards/me5_configuration.txt
> INFO: load configuration from /home/jerry/MG5_aMC_v2_3_0/input/mg5_configuration.txt
> INFO: load configuration from /home/jerry/MG5_aMC_v2_3_0/TESTEE/Cards/me5_configuration.txt
> Using default text editor "vi". Set another one in ./input/mg5_configuration.txt
> No valid SysCalc path found
> generate_events run_01
> The following switches determine which programs are run:
> 1 Run the pythia shower/hadronization: pythia=OFF
> 2 Run PGS as detector simulator: pgs=OFF
> 3 Run Delphes as detector simulator: delphes=OFF
> 4 Decay particles with the MadSpin module: madspin=OFF
> 5 Add weight to events based on coupling parameters: reweight=OFF
> Either type the switch number (1 to 5) to change its default setting,
> or set any switch explicitly (e.g. type 'madspin=ON' at the prompt)
> Type '0', 'auto', 'done' or just press enter when you are done.
> [0, 1, 2, 3, 4, 5, auto, done, pythia=ON, ... ][60s to answer]
>>
> Do you want to edit a card (press enter to bypass editing)?
> 1 / param : param_card.dat
> 2 / run : run_card.dat
> 3 / MadLoopParams : MadLoopParams.dat
> 9 / 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, MadLoopParams, 9, enter path, ... ][60s to answer]
>> 2
> open /home/jerry/MG5_aMC_v2_3_0/TESTEE/Cards/run_card.dat
> Do you want to edit a card (press enter to bypass editing)?
> 1 / param : param_card.dat
> 2 / run : run_card.dat
> 3 / MadLoopParams : MadLoopParams.dat
> 9 / 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, MadLoopParams, 9, enter path, ... ]
>>
> Generating 100 events with run name run_01
> survey run_01
> INFO: compile directory
>
> (process:7742): GLib-CRITICAL **: g_slice_set_config: assertion 'sys_page_size == 0' failed
> initMadLoop -r -f
> Initializing MadLoop loop-induced matrix elements (this can take some time)...
> MadLoop initialization finished.
> compile Source Directory
> Using random number seed offset = 21
> INFO: Running Survey
> Creating Jobs
> Working on SubProcesses
> INFO: P0_gg_h
> INFO: Idle: 1, Running: 1, Completed: 0 [ current time: 03h08 ]
> INFO: Idle: 1, Running: 0, Completed: 2 [ 2.5s ]
> INFO: P0_gg_h/G1 is at 16 +- 0.267 pb. Now submitting iteration #2.
> INFO: Idle: 0, Running: 1, Completed: 4 [ 7.5s ]
> INFO: P0_gg_h/G1 is at 15.85 +- 0.05 pb. Now submitting iteration #3.
> INFO: Idle: 0, Running: 1, Completed: 7 [ 16.9s ]
> INFO: Survey finished for P0_gg_h/G1 at 15.72 +- 0.0483 pb
> INFO: Idle: 0, Running: 0, Completed: 9 [ 17s ]
> INFO: End survey
> refine 100
> Creating Jobs
> INFO: Refine results to 100
> INFO: Generating 100.0 unweigthed events.
> INFO: Effective Luminosity 7.25144710896 pb^-1
> INFO: need to improve 0 channels
> Current estimate of cross-section: 15.721 +- 0.048287
> INFO: Idle: 0, Running: 0, Completed: 0 [ current time: 03h08 ]
> INFO: Combining runs
> INFO: finish refine
> refine 100
> Creating Jobs
> INFO: Refine results to 100
> INFO: Generating 100.0 unweigthed events.
> INFO: Effective Luminosity 7.25144710896 pb^-1
> INFO: need to improve 0 channels
> Current estimate of cross-section: 15.721 +- 0.048287
> INFO: Idle: 0, Running: 0, Completed: 0 [ current time: 03h08 ]
> INFO: Combining runs
> INFO: finish refine
> combine_events
> INFO: Combining Events
>
>
>
> === Results Summary for run: run_01 tag: tag_1 ===
>
> Cumulative sequential time for this run: 33 seconds
> Cross-section : 15.72 +- 0.04829 pb
> Nb of events : 100
>
> running syscalc on mode parton
> INFO: Creating Plots for parton level
> INFO: Plots for parton level generated, see /home/jerry/MG5_aMC_v2_3_0/TESTEE/HTML/run_01/plots_parton.html
> INFO: End Plots for parton level
> store_events
> INFO: Storing parton level results
> INFO: End Parton
> reweight -from_cards
> decay_events -from_cards
> quit
> INFO:
>
> INFO:
>
>
> --Gerardo
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

Revision history for this message
Gerardo (galva012) said : 		#2

Thanks Olivier Mattelaer, that solved my question.

Revision history for this message
Dhruvanshu Parmar (dhruvanshu) said : 		#3

Hi,

I have a question. I am also trying to generate g g > h process. However, I followed what Gerardo did using loop_sm, but I am getting the following error and unable to generate events like him.

```
MG5_aMC>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
Kept definitions of multiparticles p / j / l+ / l- / vl / 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+
MG5_aMC>generate g g > h [QCD]
INFO: Checking for minimal orders which gives processes.
INFO: Please specify coupling orders to bypass this step.
INFO: Trying coupling order WEIGHTED<=2: WEIGTHED IS QCD+2*QED
INFO: Trying coupling order WEIGHTED<=3: WEIGTHED IS QCD+2*QED
Error detected in "generate g g > h [QCD]"
write debug file MG5_debug
If you need help with this issue please contact us on https://answers.launchpad.net/mg5amcnlo
str :
 Automatic process-order determination lead to negative constraints:
 QED: 3, QCD: -2
 Please specify the coupling orders from the command line.
```

Is something missing in my Madgraph configuration? I am using Madgraph v3_1_0.

Revision history for this message
Olivier Mattelaer (olivier-mattelaer) said : 		#4

You can either force the loop induced mode
generate g g > h [noborn=QCD]
or specify that you want only one Higgs like coupling (flagged as QED)
via
generate g g > h QED<=1 [QCD]

Cheers,

Olivier

> On 19 Aug 2021, at 09:15, Dhruvanshu Parmar <email address hidden> wrote:
>
> Question #270096 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/270096
>
> Dhruvanshu Parmar posted a new comment:
> Hi,
>
> I have a question. I am also trying to generate g g > h process.
> However, I followed what Gerardo did using loop_sm, but I am getting the
> following error and unable to generate events like him.
>
> ```
> MG5_aMC>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
> Kept definitions of multiparticles p / j / l+ / l- / vl / 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+
> MG5_aMC>generate g g > h [QCD]
> INFO: Checking for minimal orders which gives processes.
> INFO: Please specify coupling orders to bypass this step.
> INFO: Trying coupling order WEIGHTED<=2: WEIGTHED IS QCD+2*QED
> INFO: Trying coupling order WEIGHTED<=3: WEIGTHED IS QCD+2*QED
> Error detected in "generate g g > h [QCD]"
> write debug file MG5_debug
> If you need help with this issue please contact us on https://answers.launchpad.net/mg5amcnlo
> str :
> Automatic process-order determination lead to negative constraints:
> QED: 3, QCD: -2
> Please specify the coupling orders from the command line.
> ```
>
> Is something missing in my Madgraph configuration? I am using Madgraph
> v3_1_0.
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

Revision history for this message
Dhruvanshu Parmar (dhruvanshu) said : 		#5

Hi Olivier,

Thanks it solved my problem.