error in HW6 shower at NLO (wrong input for mass)

Bug #1803720 reported by Olivier Mattelaer on 2018-11-16
This bug affects 1 person
Affects Status Importance Assigned to Milestone
Paolo Torrielli

Bug Description

Hi Paolo,

When running on a (read-only) system based on Ubuntu,
the HW6 shower crash with:

At line 134 of file ../srcHerwig/madfks_hwdriver.f (unit = 5, file = 'stdin')
Fortran runtime error: Bad real number in item 6 of list input

The associated line are written below:
      WRITE(*,*)'Enter Higgs (SM) boson mass, width'
      WRITE(*,*)'Enter quark (d,u,s,c,b) and gluon masses'
      READ(*,*)RMASS(1),RMASS(2),RMASS(3),RMASS(4),RMASS(5),RMASS(13) # This is 134!!!

Now if I look at what I guess is the input file (end of this email the full file):

  125.0 0.006382339 ! M_H, Ga_H
  0.32 0.32 0.5 1.55 0.75 ! quark and gluon masses

It sounds clear that one entry is missing in that line.

Is this a 4/5 flavour issue?

I'm running now on my laptop to test ( p p > t t~ [QCD]) but I guess that even if I do not have a crash this problem might still be present.

What is your opinion on this? (and how do you think that we have to solve that issue)



cat /home/vagrant/MG5_singularity/MG5/PROCNLO_loop_sm_2/MCatNLO/RUN_HERWIG6_2/MCATNLO_HERWIG6_input
 'events.lhe' ! event file
  10000 ! number of events
  1 ! 0->Herwig PDFs, 1 otherwise
 'P' 'P' ! hadron types
  6500.0 6500.0 ! beam momenta
  .FALSE. ! Underlying event on (.TRUE.) or off (.FALSE.)
 'LHAPDF' ! PDF group (1)
  244800 ! PDF id number (1)
 'LHAPDF' ! PDF group (2)
  244800 ! PDF id number (2)
  -1.000 ! Lambda_5, < 0 for default
  91.188 2.441404 ! M_Z, Gamma_Z
  80.419002 2.0476 ! M_W, Gamma_W
  173.0 1.4915 ! M_top, Gamma_top
  125.0 0.006382339 ! M_H, Ga_H
  0.32 0.32 0.5 1.55 0.75 ! quark and gluon masses
  0.000510999 0.105658 1.77682 ! Lepton masses
  2 ! Number of events to be printed out
  0.100 ! Tolerated fraction of errors
  .FALSE. ! .TRUE. if it is single-top production
  .FALSE. ! .TRUE. if it is b-bbar production
  0 0 ! First and second random seeds (0 0 for default)
  .TRUE. ! .TRUE. if one wants Pi0 stable
  .FALSE. ! .TRUE. if one wants W+ stable
  .FALSE. ! .TRUE. if one wants W- stable
  .FALSE. ! .TRUE. if one wants Z0 stable
  .FALSE. ! .TRUE. if one wants tau+ stable
  .FALSE. ! .TRUE. if one wants tau- stable
  .FALSE. ! .TRUE. if one wants mu+ stable
  .FALSE. ! .TRUE. if one wants mu- stable
  .FALSE. ! .TRUE. if one wants Higgs stable
  0 ! Number of decay modes set by user
  average ! Event weights are normalized to sun or average to the cross section

Just to report my result on my mac:
the file is like this:

  125.0 0.006382339 ! M_H, Ga_H
  0.32 0.32 0.5 1.55 4.95 0.75 ! quark and gluon masses

So in this case no issue at ALL (good, I was worried that it was returning something stupid)

Paolo gave me the solution via skype.

A hidden dependencies of MC@NLO was missing on my ubuntu installation.
running apt-get install bc was fixing the issue.

I will push in 2.6.5 a patch to check for such dependencies.

Thanks Paolo,


Changed in mg5amcnlo:
status: New → Fix Committed
Changed in mg5amcnlo:
status: Fix Committed → Fix Released
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