Pythia8 reading problem LHE file generated by MG5_aMC

Hi,

Pythia8.1 is not able to shower LHEF version3 event.
So you have two solutions:
1) user Pythia8.2
2) ask MG to generate LHEF version 1/2 event. You can choose the version format via the run_card (lhe_version parameter)

> Is there any way to generate HepMC output directly from MG5_aMC ?

No

Cheers,

Olivier

On 27 Apr 2015, at 08:06, Saurabh Niyogi <email address hidden> wrote:

> New question #265962 on MadGraph5_aMC@NLO:
> https://answers.launchpad.net/mg5amcnlo/+question/265962
>
> I use MG5_aMC_v2_2_3 to generate required process. I need hepmc formatted output. Therefore, I manually run Pythia8 (v8186) with the .lhe event file to get hepmc output. I have installed MG5, Pythia8. HepMC and they are running fine. Now, an LHE file generated by MG5_aMC_v2_2_3 is not running in Pythia8186. It is shwoing some error message:
>
> PYTHIA Abort from Pythia::init: Les Houches initialization failed
> PYTHIA Abort from Pythia::next: not properly initialized so cannot generate events
>
> But, Pythia8 runs smoothly with the output LHE file from older Madgraph version (MG5_v1_5_12) and produces correct hepmc output. Can you please tell me if there is some problem, or, I am doing it incorrectly ? Is there any way to generate HepMC output directly from MG5_aMC ?
>
> Thanks,
> Saurabh
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

Hi Olivier,

  Thanks a lot. It solves my problem.

Cheers,
Saurabh

Now i recently installed madgraph v2.7.2 and there is no option of lhe_version in Run card. Now how i can change lhe_version??

#*********************************************************************
# Type and output format
#*********************************************************************
  False = gridpack !True = setting up the grid pack
  -1.0 = time_of_flight ! threshold (in mm) below which the invariant livetime is not written (-1 means not written)
  average = event_norm ! average/sum. Normalization of the weight in the LHEF
# To see MLM/CKKW merging options: type "update MLM" or "update CKKW"

#*********************************************************************

#*********************************************************************

You can add the parameter within the card like in the previous version of the code
(or use the command set lhe_version X)

This was hidden to make the card shorter

Cheers,

Olivier

yes i added but i again got the LHE file with lhe_version 1.0.

<LesHouchesEvents version="1.0">
<header>
<!--
#*********************************************************************
# *
# MadGraph5_aMC@NLO *
# *
# Going Beyond *
# *
# http://madgraph.hep.uiuc.edu *
# http://madgraph.phys.ucl.ac.be *
# http://amcatnlo.cern.ch *
# *
# The MadGraph5_aMC@NLO team *
# *
#....................................................................*
# *
# This file contains all the information necessary to reproduce *
# the events generated: *
# *
# 1. software version *
# 2. proc_card : code generation info including model *
# 3. param_card : model primary parameters in the LH format *
# 4. run_card : running parameters (collider and cuts) *
# 5. pythia_card : present only if pythia has been run *
# 6. pgs_card : present only if pgs has been run *
# 7. delphes_cards : present only if delphes has been run *
# *
# *
#*********************************************************************
-->
<MGVersion>
2.7.2
</MGVersion>
<MG5ProcCard>
<![CDATA[
#************************************************************
#* MadGraph5_aMC@NLO *
#* *
#* * * *
#* * * * * *
#* * * * * 5 * * * * *
#* * * * * *
#* * * *
#* *
#* *
#* VERSION 2.7.2 2020-03-17 *
#* *
#* The MadGraph5_aMC@NLO Development Team - Find us at *
#* https://server06.fynu.ucl.ac.be/projects/madgraph *
#* *
#************************************************************
#* *
#* Command File for MadGraph5_aMC@NLO *
#* *
#* run as ./bin/mg5_aMC filename *
#* *
#************************************************************
set default_unset_couplings 99
set group_subprocesses Auto
set ignore_six_quark_processes False
set loop_optimized_output True
set low_mem_multicore_nlo_generation False
set loop_color_flows False
set gauge unitary
set complex_mass_scheme False
set max_npoint_for_channel 0
import model sm
define p = g u c d s u~ c~ d~ s~
define j = g u c d s u~ c~ d~ s~
define l+ = e+ mu+
define l- = e- mu-
define vl = ve vm vt
define vl~ = ve~ vm~ vt~
set nb_core 1
save options
import model 2HDM
generate e+ e- > z h2 h2, z > l+ l-, h2 > b b~
output eeTozhh
]]>
</MG5ProcCard>
<MGProcCard>
#*********************************************************************
# MadGraph/MadEvent *
# http://madgraph.hep.uiuc.edu *
# *
# proc_card.dat *
#*********************************************************************
# *
# This Files is generated by MADGRAPH 5 *
# *
# WARNING: This Files is generated for MADEVENT (compatibility issue)*
# This files is NOT a valid MG4 proc_card.dat *
# Running this in MG4 will NEVER reproduce the result of MG5*
# *
#*********************************************************************
#*********************************************************************
# Process(es) requested : mg2 input *
#*********************************************************************
# Begin PROCESS # This is TAG. Do not modify this line
e+ e- > z h2 h2 , z > l+ l- , h2 > b b~ #Process
# Be carefull the coupling are here in MG5 convention

end_coup # End the couplings input

done # this tells MG there are no more procs
# End PROCESS # This is TAG. Do not modify this line
#*********************************************************************
# Model information *
#*********************************************************************
# Begin MODEL # This is TAG. Do not modify this line
2HDM
# End MODEL # This is TAG. Do not modify this line
#*********************************************************************
# Start multiparticle definitions *
#*********************************************************************
# Begin MULTIPARTICLES # This is TAG. Do not modify this line

# End MULTIPARTICLES # This is TAG. Do not modify this line
</MGProcCard>
<MGRunCard>
<![CDATA[
#*********************************************************************
# MadGraph5_aMC@NLO *
# *
# run_card.dat MadEvent *
# *
# This file is used to set the parameters of the run. *
# *
# Some notation/conventions: *
# *
# Lines starting with a '# ' are info or comments *
# *
# mind the format: value = variable ! comment *
# *
# To display more options, you can type the command: *
# update full_run_card *
#*********************************************************************
#
#*********************************************************************
# Tag name for the run (one word) *
#*********************************************************************
  tag_1 = run_tag ! name of the run
#*********************************************************************
# Number of events and rnd seed *
# Warning: Do not generate more than 1M events in a single run *
#*********************************************************************
  50000 = nevents ! Number of unweighted events requested
 21 = iseed ! rnd seed (0=assigned automatically=default))
#*********************************************************************
# Collider type and energy *
# lpp: 0=No PDF, 1=proton, -1=antiproton, 2=photon from proton, *
# 3=photon from electron *
#*********************************************************************
     0 = lpp1 ! beam 1 type
     0 = lpp2 ! beam 2 type
     1500.0 = ebeam1 ! beam 1 total energy in GeV
     1500.0 = ebeam2 ! beam 2 total energy in GeV
#*********************************************************************
# Beam polarization from -100 (left-handed) to 100 (right-handed) *
#*********************************************************************
     0.0 = polbeam1 ! beam polarization for beam 1
     0.0 = polbeam2 ! beam polarization for beam 2

#*********************************************************************
# PDF CHOICE: this automatically fixes also alpha_s and its evol. *
#*********************************************************************
     nn23lo1 = pdlabel ! PDF set
     230000 = lhaid ! if pdlabel=lhapdf, this is the lhapdf number
# To see heavy ion options: type "update ion_pdf"
#*********************************************************************
# Renormalization and factorization scales *
#*********************************************************************
 False = fixed_ren_scale ! if .true. use fixed ren scale
 False = fixed_fac_scale ! if .true. use fixed fac scale
 91.188 = scale ! fixed ren scale
 91.188 = dsqrt_q2fact1 ! fixed fact scale for pdf1
 91.188 = dsqrt_q2fact2 ! fixed fact scale for pdf2
 -1 = dynamical_scale_choice ! Choose one of the preselected dynamical choices
 1.0 = scalefact ! scale factor for event-by-event scales
#*********************************************************************
# Type and output format
#*********************************************************************
  False = gridpack !True = setting up the grid pack
  -1.0 = time_of_flight ! threshold (in mm) below which the invariant livetime is not written (-1 means not written)
  average = event_norm ! average/sum. Normalization of the weight in the LHEF
# To see MLM/CKKW merging options: type "update MLM" or "update CKKW"
    2.0 = lhe_version
#*********************************************************************
#
#*********************************************************************
# handling of the helicities:
# 0: sum over all helicities
# 1: importance sampling over helicities
#*********************************************************************
   0 = nhel ! using helicities importance sampling or not.
#*********************************************************************
# Generation bias, check the wiki page below for more information: *
# 'cp3.irmp.ucl.ac.be/projects/madgraph/wiki/LOEventGenerationBias' *
#*********************************************************************
 None = bias_module ! Bias type of bias, [None, ptj_bias, -custom_folder-]
 {} = bias_parameters ! Specifies the parameters of the module.

This is normal,

Since MG5aMC does not use the features of version 2, we are actually cmptabile with both version 1 and 2 and therefore write here version 1.

Cheers,

Olivier

> On 2 Apr 2020, at 18:47, Muhammad Danish Aslam <email address hidden> wrote:
>
> Question #265962 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/265962
>
> Muhammad Danish Aslam posted a new comment:
> yes i added but i again got the LHE file with lhe_version 1.0.
>
> <LesHouchesEvents version="1.0">
> <header>
> <!--
> #*********************************************************************
> # *
> # MadGraph5_aMC@NLO *
> # *
> # Going Beyond *
> # *
> # http://madgraph.hep.uiuc.edu *
> # http://madgraph.phys.ucl.ac.be *
> # http://amcatnlo.cern.ch *
> # *
> # The MadGraph5_aMC@NLO team *
> # *
> #....................................................................*
> # *
> # This file contains all the information necessary to reproduce *
> # the events generated: *
> # *
> # 1. software version *
> # 2. proc_card : code generation info including model *
> # 3. param_card : model primary parameters in the LH format *
> # 4. run_card : running parameters (collider and cuts) *
> # 5. pythia_card : present only if pythia has been run *
> # 6. pgs_card : present only if pgs has been run *
> # 7. delphes_cards : present only if delphes has been run *
> # *
> # *
> #*********************************************************************
> -->
> <MGVersion>
> 2.7.2
> </MGVersion>
> <MG5ProcCard>
> <![CDATA[
> #************************************************************
> #* MadGraph5_aMC@NLO *
> #* *
> #* * * *
> #* * * * * *
> #* * * * * 5 * * * * *
> #* * * * * *
> #* * * *
> #* *
> #* *
> #* VERSION 2.7.2 2020-03-17 *
> #* *
> #* The MadGraph5_aMC@NLO Development Team - Find us at *
> #* https://server06.fynu.ucl.ac.be/projects/madgraph *
> #* *
> #************************************************************
> #* *
> #* Command File for MadGraph5_aMC@NLO *
> #* *
> #* run as ./bin/mg5_aMC filename *
> #* *
> #************************************************************
> set default_unset_couplings 99
> set group_subprocesses Auto
> set ignore_six_quark_processes False
> set loop_optimized_output True
> set low_mem_multicore_nlo_generation False
> set loop_color_flows False
> set gauge unitary
> set complex_mass_scheme False
> set max_npoint_for_channel 0
> import model sm
> define p = g u c d s u~ c~ d~ s~
> define j = g u c d s u~ c~ d~ s~
> define l+ = e+ mu+
> define l- = e- mu-
> define vl = ve vm vt
> define vl~ = ve~ vm~ vt~
> set nb_core 1
> save options
> import model 2HDM
> generate e+ e- > z h2 h2, z > l+ l-, h2 > b b~
> output eeTozhh
> ]]>
> </MG5ProcCard>
> <MGProcCard>
> #*********************************************************************
> # MadGraph/MadEvent *
> # http://madgraph.hep.uiuc.edu *
> # *
> # proc_card.dat *
> #*********************************************************************
> # *
> # This Files is generated by MADGRAPH 5 *
> # *
> # WARNING: This Files is generated for MADEVENT (compatibility issue)*
> # This files is NOT a valid MG4 proc_card.dat *
> # Running this in MG4 will NEVER reproduce the result of MG5*
> # *
> #*********************************************************************
> #*********************************************************************
> # Process(es) requested : mg2 input *
> #*********************************************************************
> # Begin PROCESS # This is TAG. Do not modify this line
> e+ e- > z h2 h2 , z > l+ l- , h2 > b b~ #Process
> # Be carefull the coupling are here in MG5 convention
>
> end_coup # End the couplings input
>
> done # this tells MG there are no more procs
> # End PROCESS # This is TAG. Do not modify this line
> #*********************************************************************
> # Model information *
> #*********************************************************************
> # Begin MODEL # This is TAG. Do not modify this line
> 2HDM
> # End MODEL # This is TAG. Do not modify this line
> #*********************************************************************
> # Start multiparticle definitions *
> #*********************************************************************
> # Begin MULTIPARTICLES # This is TAG. Do not modify this line
>
> # End MULTIPARTICLES # This is TAG. Do not modify this line
> </MGProcCard>
> <MGRunCard>
> <![CDATA[
> #*********************************************************************
> # MadGraph5_aMC@NLO *
> # *
> # run_card.dat MadEvent *
> # *
> # This file is used to set the parameters of the run. *
> # *
> # Some notation/conventions: *
> # *
> # Lines starting with a '# ' are info or comments *
> # *
> # mind the format: value = variable ! comment *
> # *
> # To display more options, you can type the command: *
> # update full_run_card *
> #*********************************************************************
> #
> #*********************************************************************
> # Tag name for the run (one word) *
> #*********************************************************************
> tag_1 = run_tag ! name of the run
> #*********************************************************************
> # Number of events and rnd seed *
> # Warning: Do not generate more than 1M events in a single run *
> #*********************************************************************
> 50000 = nevents ! Number of unweighted events requested
> 21 = iseed ! rnd seed (0=assigned automatically=default))
> #*********************************************************************
> # Collider type and energy *
> # lpp: 0=No PDF, 1=proton, -1=antiproton, 2=photon from proton, *
> # 3=photon from electron *
> #*********************************************************************
> 0 = lpp1 ! beam 1 type
> 0 = lpp2 ! beam 2 type
> 1500.0 = ebeam1 ! beam 1 total energy in GeV
> 1500.0 = ebeam2 ! beam 2 total energy in GeV
> #*********************************************************************
> # Beam polarization from -100 (left-handed) to 100 (right-handed) *
> #*********************************************************************
> 0.0 = polbeam1 ! beam polarization for beam 1
> 0.0 = polbeam2 ! beam polarization for beam 2
>
>
> #*********************************************************************
> # PDF CHOICE: this automatically fixes also alpha_s and its evol. *
> #*********************************************************************
> nn23lo1 = pdlabel ! PDF set
> 230000 = lhaid ! if pdlabel=lhapdf, this is the lhapdf number
> # To see heavy ion options: type "update ion_pdf"
> #*********************************************************************
> # Renormalization and factorization scales *
> #*********************************************************************
> False = fixed_ren_scale ! if .true. use fixed ren scale
> False = fixed_fac_scale ! if .true. use fixed fac scale
> 91.188 = scale ! fixed ren scale
> 91.188 = dsqrt_q2fact1 ! fixed fact scale for pdf1
> 91.188 = dsqrt_q2fact2 ! fixed fact scale for pdf2
> -1 = dynamical_scale_choice ! Choose one of the preselected dynamical choices
> 1.0 = scalefact ! scale factor for event-by-event scales
> #*********************************************************************
> # Type and output format
> #*********************************************************************
> False = gridpack !True = setting up the grid pack
> -1.0 = time_of_flight ! threshold (in mm) below which the invariant livetime is not written (-1 means not written)
> average = event_norm ! average/sum. Normalization of the weight in the LHEF
> # To see MLM/CKKW merging options: type "update MLM" or "update CKKW"
> 2.0 = lhe_version
> #*********************************************************************
> #
> #*********************************************************************
> # handling of the helicities:
> # 0: sum over all helicities
> # 1: importance sampling over helicities
> #*********************************************************************
> 0 = nhel ! using helicities importance sampling or not.
> #*********************************************************************
> # Generation bias, check the wiki page below for more information: *
> # 'cp3.irmp.ucl.ac.be/projects/madgraph/wiki/LOEventGenerationBias' *
> #*********************************************************************
> None = bias_module ! Bias type of bias, [None, ptj_bias, -custom_folder-]
> {} = bias_parameters ! Specifies the parameters of the module.
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.