Error computing decay width with vertex involving a form factor defined in functions.f

Hi,

The auto-width tools (1402.1178 [hep-ph]) only supports real UFO model ( 1108.2040 [hep-ph]).
The method 2 broke the convention of the UFO paper making him compatible only with the fortran code output of MG5aMC.

The issue here is that that auto-width code is not able to estimate the value of "FFGGH" since that code is a python code that can not read your fortran file. Knowing if FFGGH is like "1" or "M^2" or "M^6" is important in order to determine which computation needs to be done. (Can we stop at two body decay or not in particular).

My suggestion is to go back to the method that was available before 2014, i.e. compute the width with madevent and copy the param_card.
i.e. do the following
generate X > x1 x2
add process X > x3 x4
add process X > x5 x6 x7
output
launch -i
calculate_decay_widths

at the end of the run you will see:
Results written to /Users/omattelaer/Documents/workspace/2.7.3/PROC_sm_40/Events/run_01/param_card.dat

and you can just use that card as input for your normal generation.
Not as simple/ellegant as the "Auto" width but it will work

Cheers,

Olivier

Hi Olivier,

Thank you for the explanation!

I implemented the same form factor using "Method 1" described in https://cp3.irmp.ucl.ac.be/projects/madgraph/wiki/FormFactors

I'm still getting a similar message when I set the width of a particle to "Auto":

INFO: get decay diagram for h
Vertexlist of this model has not been searched.Automatically run the model.find_vertexlist()
Found 3 stable particles
Command "generate_events run_01" interrupted in sub-command:
"set max_npoint_for_channel 0" with error:
NameError : name 'FFGGH' is not defined

For calculations where the width is specified, FFGGH seems to be well defined.

Any idea what might be the problem now?

Thank you,
Nicolas

MG5_debug file:
#************************************************************
#* MadGraph5_aMC@NLO *
#* *
#* * * *
#* * * * * *
#* * * * * 5 * * * * *
#* * * * * *
#* * * *
#* *
#* *
#* VERSION 2.7.3 2020-06-21 *
#* *
#* 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 loop_color_flows False
set gauge unitary
set complex_mass_scheme False
set max_npoint_for_channel 0
Traceback (most recent call last):
  File "/home/nico/bin/MG5_aMC_v2_7_3/madgraph/interface/extended_cmd.py", line 1515, in onecmd
    return self.onecmd_orig(line, **opt)
  File "/home/nico/bin/MG5_aMC_v2_7_3/madgraph/interface/extended_cmd.py", line 1464, in onecmd_orig
    return func(arg, **opt)
  File "/home/nico/bin/MG5_aMC_v2_7_3/madgraph/interface/madevent_interface.py", line 2460, in do_generate_events
    switch_mode = self.ask_run_configuration(mode, args)
  File "/home/nico/bin/MG5_aMC_v2_7_3/madgraph/interface/madevent_interface.py", line 6222, in ask_run_configuration
    self.ask_edit_cards(cards, plot=False, first_cmd=first_cmd)
  File "/home/nico/bin/MG5_aMC_v2_7_3/madgraph/interface/common_run_interface.py", line 966, in ask_edit_cards
    banner=banner)
  File "/home/nico/bin/MG5_aMC_v2_7_3/madgraph/interface/common_run_interface.py", line 1038, in ask_edit_card_static
    cards=cards, mode=mode, **opt)
  File "/home/nico/bin/MG5_aMC_v2_7_3/madgraph/interface/extended_cmd.py", line 1114, in ask
    question_instance.postcmd(answer, line)
  File "/home/nico/bin/MG5_aMC_v2_7_3/madgraph/interface/common_run_interface.py", line 6014, in postcmd
    self.do_update('dependent', timer=20)
  File "/home/nico/bin/MG5_aMC_v2_7_3/madgraph/interface/common_run_interface.py", line 6060, in do_update
    self.do_compute_widths('')
  File "/home/nico/bin/MG5_aMC_v2_7_3/madgraph/interface/common_run_interface.py", line 6431, in do_compute_widths
    out = self.mother_interface.do_compute_widths(line)
  File "/home/nico/bin/MG5_aMC_v2_7_3/madgraph/interface/common_run_interface.py", line 2299, in do_compute_widths
    out = cmd.exec_cmd(line, model=opts['model'])
  File "/home/nico/bin/MG5_aMC_v2_7_3/madgraph/interface/extended_cmd.py", line 1544, in exec_cmd
    stop = Cmd.onecmd_orig(current_interface, line, **opt)
  File "/home/nico/bin/MG5_aMC_v2_7_3/madgraph/interface/extended_cmd.py", line 1464, in onecmd_orig
    return func(arg, **opt)
  File "/home/nico/bin/MG5_aMC_v2_7_3/madgraph/interface/master_interface.py", line 345, in do_compute_widths
    return self.cmd.do_compute_widths(self, *args, **opts)
  File "/home/nico/bin/MG5_aMC_v2_7_3/madgraph/interface/madgraph_interface.py", line 8340, in do_compute_widths
    ), skip_2body=skip_2body, model=decaymodel)
  File "/home/nico/bin/MG5_aMC_v2_7_3/madgraph/interface/master_interface.py", line 333, in do_decay_diagram
    return self.cmd.do_decay_diagram(self, *args, **opts)
  File "/home/nico/bin/MG5_aMC_v2_7_3/madgraph/interface/madgraph_interface.py", line 8614, in do_decay_diagram
    model.find_all_channels(2,generate_abstract=False)
  File "/home/nico/bin/MG5_aMC_v2_7_3/mg5decay/decay_objects.py", line 2845, in find_all_channels
    part.find_channels_nextlevel(self, min_br)
  File "/home/nico/bin/MG5_aMC_v2_7_3/mg5decay/decay_objects.py", line 914, in find_channels_nextlevel
    self['apx_decaywidth'] += temp_channel.get_apx_decaywidth(model)
  File "/home/nico/bin/MG5_aMC_v2_7_3/mg5decay/decay_objects.py", line 4424, in get_apx_decaywidth
    self.get_apx_psarea(model)/ \
  File "/home/nico/bin/MG5_aMC_v2_7_3/mg5decay/decay_objects.py", line 4097, in get_apx_matrixelement_sq
    lor_value = eval(new_structure % q_dict_lor)
  File "<string>", line 1, in <module>
NameError: name 'FFGGH' is not defined
                          MadGraph5_aMC@NLO Options
                          ----------------
        complex_mass_scheme : False
    default_unset_couplings : 99 (user set)
                      gauge : unitary
         group_subprocesses : Auto
  ignore_six_quark_processes : False
           loop_color_flows : False
      loop_optimized_output : True
  low_mem_multicore_nlo_generation : False
     max_npoint_for_channel : 0 (user set)
               stdout_level : 20 (user set)

                         MadEvent Options
                          ----------------
     automatic_html_opening : False (user set)
                    nb_core : 4 (user set)
        notification_center : True
                   run_mode : 2

                      Configuration Options
                      ---------------------
                        OLP : MadLoop
                    amcfast : amcfast-config
                   applgrid : applgrid-config
                auto_update : 0 (user set)
         cluster_local_path : None
           cluster_nb_retry : 1
              cluster_queue : None (user set)
         cluster_retry_wait : 300
               cluster_size : 100
      cluster_status_update : (600, 30)
          cluster_temp_path : None
               cluster_type : condor
                    collier : ./HEPTools/lib
               cpp_compiler : None
             crash_on_error : False
               delphes_path : None (user set)
                 eps_viewer : None
        exrootanalysis_path : None (user set)
              f2py_compiler : None
                    fastjet : None (user set)
           fortran_compiler : None
                      golem : None (user set)
                 hepmc_path : None (user set)
                  hwpp_path : None (user set)
                     lhapdf : lhapdf-config
          madanalysis5_path : None (user set)
           madanalysis_path : None (user set)
  mg5amc_py8_interface_path : None (user set)
                      ninja : ./HEPTools/lib
        output_dependencies : external
            pythia-pgs_path : None (user set)
               pythia8_path : None (user set)
                    samurai : None
               syscalc_path : None (user set)
                    td_path : None (user set)
                text_editor : None
                thepeg_path : None (user set)
                    timeout : 60
                web_browser : None

Hi,

Sorry I thought that such case was supported and looks like I was wrong (sorry it is difficult to know which sub-feature of the code is compatible with each sub-feature of the code even for me who wrote most of them.

In any case, now that this is in Python, I can easily include such support:
You will need this patch (or you can directly download the tarball)
https://bazaar.launchpad.net/~mg5core1/mg5amcnlo/2.7.4/revision/290 <https://bazaar.launchpad.net/~mg5core1/mg5amcnlo/2.7.4/revision/290>

Thanks,

Olivier

> On 25 Jun 2020, at 17:50, Nicolas A. Neill <email address hidden> wrote:
>
> Question #691518 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/691518
>
> Status: Answered => Open
>
> Nicolas A. Neill is still having a problem:
> Hi Olivier,
>
> Thank you for the explanation!
>
> I implemented the same form factor using "Method 1" described in
> https://cp3.irmp.ucl.ac.be/projects/madgraph/wiki/FormFactors
>
> I'm still getting a similar message when I set the width of a particle
> to "Auto":
>
> INFO: get decay diagram for h
> Vertexlist of this model has not been searched.Automatically run the model.find_vertexlist()
> Found 3 stable particles
> Command "generate_events run_01" interrupted in sub-command:
> "set max_npoint_for_channel 0" with error:
> NameError : name 'FFGGH' is not defined
>
> For calculations where the width is specified, FFGGH seems to be well
> defined.
>
> Any idea what might be the problem now?
>
> Thank you,
> Nicolas
>
>
> MG5_debug file:
> #************************************************************
> #* MadGraph5_aMC@NLO *
> #* *
> #* * * *
> #* * * * * *
> #* * * * * 5 * * * * *
> #* * * * * *
> #* * * *
> #* *
> #* *
> #* VERSION 2.7.3 2020-06-21 *
> #* *
> #* 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 loop_color_flows False
> set gauge unitary
> set complex_mass_scheme False
> set max_npoint_for_channel 0
> Traceback (most recent call last):
> File "/home/nico/bin/MG5_aMC_v2_7_3/madgraph/interface/extended_cmd.py", line 1515, in onecmd
> return self.onecmd_orig(line, **opt)
> File "/home/nico/bin/MG5_aMC_v2_7_3/madgraph/interface/extended_cmd.py", line 1464, in onecmd_orig
> return func(arg, **opt)
> File "/home/nico/bin/MG5_aMC_v2_7_3/madgraph/interface/madevent_interface.py", line 2460, in do_generate_events
> switch_mode = self.ask_run_configuration(mode, args)
> File "/home/nico/bin/MG5_aMC_v2_7_3/madgraph/interface/madevent_interface.py", line 6222, in ask_run_configuration
> self.ask_edit_cards(cards, plot=False, first_cmd=first_cmd)
> File "/home/nico/bin/MG5_aMC_v2_7_3/madgraph/interface/common_run_interface.py", line 966, in ask_edit_cards
> banner=banner)
> File "/home/nico/bin/MG5_aMC_v2_7_3/madgraph/interface/common_run_interface.py", line 1038, in ask_edit_card_static
> cards=cards, mode=mode, **opt)
> File "/home/nico/bin/MG5_aMC_v2_7_3/madgraph/interface/extended_cmd.py", line 1114, in ask
> question_instance.postcmd(answer, line)
> File "/home/nico/bin/MG5_aMC_v2_7_3/madgraph/interface/common_run_interface.py", line 6014, in postcmd
> self.do_update('dependent', timer=20)
> File "/home/nico/bin/MG5_aMC_v2_7_3/madgraph/interface/common_run_interface.py", line 6060, in do_update
> self.do_compute_widths('')
> File "/home/nico/bin/MG5_aMC_v2_7_3/madgraph/interface/common_run_interface.py", line 6431, in do_compute_widths
> out = self.mother_interface.do_compute_widths(line)
> File "/home/nico/bin/MG5_aMC_v2_7_3/madgraph/interface/common_run_interface.py", line 2299, in do_compute_widths
> out = cmd.exec_cmd(line, model=opts['model'])
> File "/home/nico/bin/MG5_aMC_v2_7_3/madgraph/interface/extended_cmd.py", line 1544, in exec_cmd
> stop = Cmd.onecmd_orig(current_interface, line, **opt)
> File "/home/nico/bin/MG5_aMC_v2_7_3/madgraph/interface/extended_cmd.py", line 1464, in onecmd_orig
> return func(arg, **opt)
> File "/home/nico/bin/MG5_aMC_v2_7_3/madgraph/interface/master_interface.py", line 345, in do_compute_widths
> return self.cmd.do_compute_widths(self, *args, **opts)
> File "/home/nico/bin/MG5_aMC_v2_7_3/madgraph/interface/madgraph_interface.py", line 8340, in do_compute_widths
> ), skip_2body=skip_2body, model=decaymodel)
> File "/home/nico/bin/MG5_aMC_v2_7_3/madgraph/interface/master_interface.py", line 333, in do_decay_diagram
> return self.cmd.do_decay_diagram(self, *args, **opts)
> File "/home/nico/bin/MG5_aMC_v2_7_3/madgraph/interface/madgraph_interface.py", line 8614, in do_decay_diagram
> model.find_all_channels(2,generate_abstract=False)
> File "/home/nico/bin/MG5_aMC_v2_7_3/mg5decay/decay_objects.py", line 2845, in find_all_channels
> part.find_channels_nextlevel(self, min_br)
> File "/home/nico/bin/MG5_aMC_v2_7_3/mg5decay/decay_objects.py", line 914, in find_channels_nextlevel
> self['apx_decaywidth'] += temp_channel.get_apx_decaywidth(model)
> File "/home/nico/bin/MG5_aMC_v2_7_3/mg5decay/decay_objects.py", line 4424, in get_apx_decaywidth
> self.get_apx_psarea(model)/ \
> File "/home/nico/bin/MG5_aMC_v2_7_3/mg5decay/decay_objects.py", line 4097, in get_apx_matrixelement_sq
> lor_value = eval(new_structure % q_dict_lor)
> File "<string>", line 1, in <module>
> NameError: name 'FFGGH' is not defined
> MadGraph5_aMC@NLO Options
> ----------------
> complex_mass_scheme : False
> default_unset_couplings : 99 (user set)
> gauge : unitary
> group_subprocesses : Auto
> ignore_six_quark_processes : False
> loop_color_flows : False
> loop_optimized_output : True
> low_mem_multicore_nlo_generation : False
> max_npoint_for_channel : 0 (user set)
> stdout_level : 20 (user set)
>
> MadEvent Options
> ----------------
> automatic_html_opening : False (user set)
> nb_core : 4 (user set)
> notification_center : True
> run_mode : 2
>
> Configuration Options
> ---------------------
> OLP : MadLoop
> amcfast : amcfast-config
> applgrid : applgrid-config
> auto_update : 0 (user set)
> cluster_local_path : None
> cluster_nb_retry : 1
> cluster_queue : None (user set)
> cluster_retry_wait : 300
> cluster_size : 100
> cluster_status_update : (600, 30)
> cluster_temp_path : None
> cluster_type : condor
> collier : ./HEPTools/lib
> cpp_compiler : None
> crash_on_error : False
> delphes_path : None (user set)
> eps_viewer : None
> exrootanalysis_path : None (user set)
> f2py_compiler : None
> fastjet : None (user set)
> fortran_compiler : None
> golem : None (user set)
> hepmc_path : None (user set)
> hwpp_path : None (user set)
> lhapdf : lhapdf-config
> madanalysis5_path : None (user set)
> madanalysis_path : None (user set)
> mg5amc_py8_interface_path : None (user set)
> ninja : ./HEPTools/lib
> output_dependencies : external
> pythia-pgs_path : None (user set)
> pythia8_path : None (user set)
> samurai : None
> syscalc_path : None (user set)
> td_path : None (user set)
> text_editor : None
> thepeg_path : None (user set)
> timeout : 60
> web_browser : None
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

Hi Olivier,

Thanks a lot! Now the auto width calculation works fine with the form factors.

However, it looks like the functions from 'function_library.py' can not be accessed for auto width calculations (even though they work fine when the width is specified externally).

For example, trying to use 'csc' in the form factor (which is being imported from 'function_library.py' at the beginning of 'form_factors.py') gives this error:

Command "generate_events run_01" interrupted in sub-command:
"set max_npoint_for_channel 0" with error:
NameError : name 'csc' is not defined
Please report this bug on https://bugs.launchpad.net/mg5amcnlo
More information is found in 'MG5_debug'.
Please attach this file to your report.

Is there any way to make these functions available when using auto width?

Thanks,
Nicolas

Hi Olivier,

It works great!

Thank you,
Nicolas

Thanks Olivier Mattelaer, that solved my question.