Error trying to generate NLO-QED e+e- -> HZ events

Asked by Muanza on 2020-04-27

Dear authors,
                          I tried to generate the HZ process in e+e- collisions including NLO-QED corrections using v3.0.1. I got the following error message:

Error detected in "launch auto "
write debug file /sps/atlas/m/muanza/MC/MADGRAPH/MG5_aMC_v3_0_1/ee_HZ_NLO_QED_240_12345/run_01_tag_1_debug.log
If you need help with this issue, please, contact us on https://answers.launchpad.net/mg5amcnlo
aMCatNLOError : Poles do not cancel, run cannot continue
 Here is the steering card I used:

import model loop_qcd_qed_sm
set include_lepton_initiated_processes True
generate e+ e- > h z [QED] @0
set automatic_html_opening False
save options
output ee_HZ_NLO_QED_240_12345
launch ee_HZ_NLO_QED_240_12345
shower=PYTHIA8
set run_card nevents 1000
set ebeam1 120
set ebeam2 120
set iseed 12345
set mc 1.67
set mb 4.78
set mt 172.9
set mh 125.0

 and here is the debug file:

#************************************************************
#* MadGraph5_aMC@NLO *
#* *
#* * * *
#* * * * * *
#* * * * * 5 * * * * *
#* * * * * *
#* * * *
#* *
#* *
#* VERSION 3.0.1 2018-12-20 *
#* *
#* The MadGraph5_aMC@NLO Development Team - Find us at *
#* https://server06.fynu.ucl.ac.be/projects/madgraph *
#* and *
#* http://amcatnlo.cern.ch *
#* *
#************************************************************
#* *
#* Command File for aMCatNLO *
#* *
#* run as ./bin/aMCatNLO.py filename *
#* *
#************************************************************
launch auto
Traceback (most recent call last):
  File "/sps/atlas/m/muanza/MC/MADGRAPH/MG5_aMC_v3_0_1/madgraph/interface/extended_cmd.py", line 1504, in onecmd
    return self.onecmd_orig(line, **opt)
  File "/sps/atlas/m/muanza/MC/MADGRAPH/MG5_aMC_v3_0_1/madgraph/interface/extended_cmd.py", line 1453, in onecmd_orig
    return func(arg, **opt)
  File "/sps/atlas/m/muanza/MC/MADGRAPH/MG5_aMC_v3_0_1/madgraph/interface/amcatnlo_run_interface.py", line 1739, in do_launch
    self.compile(mode, options)
  File "/sps/atlas/m/muanza/MC/MADGRAPH/MG5_aMC_v3_0_1/madgraph/interface/amcatnlo_run_interface.py", line 5290, in compile
    self.check_tests(test, this_dir)
  File "/sps/atlas/m/muanza/MC/MADGRAPH/MG5_aMC_v3_0_1/madgraph/interface/amcatnlo_run_interface.py", line 5303, in check_tests
    return self.parse_check_poles_log(pjoin(dir, '%s.log' % test))
  File "/sps/atlas/m/muanza/MC/MADGRAPH/MG5_aMC_v3_0_1/madgraph/interface/amcatnlo_run_interface.py", line 5336, in parse_check_poles_log
    raise aMCatNLOError('Poles do not cancel, run cannot continue')
aMCatNLOError: Poles do not cancel, run cannot continue
Value of current Options:
              text_editor : None
      notification_center : True
                    pjfry : None
       cluster_local_path : None
  default_unset_couplings : 99
       group_subprocesses : Auto
ignore_six_quark_processes : False
    loop_optimized_output : True
    cluster_status_update : (600, 30)
         fortran_compiler : None
               hepmc_path : /sps/atlas/m/muanza/MC/MADGRAPH/MG5_aMC_v3_0_1/HEPTools/hepmc
                  collier : /sps/atlas/m/muanza/MC/MADGRAPH/MG5_aMC_v3_0_1/HEPTools/lib
              auto_update : 7
             pythia8_path : /sps/atlas/m/muanza/MC/MADGRAPH/MG5_aMC_v3_0_1/HEPTools/pythia8
                hwpp_path : None
low_mem_multicore_nlo_generation : False
                    golem : None
          pythia-pgs_path : None
                  td_path : None
             delphes_path : None
              thepeg_path : None
             cluster_type : condor
        madanalysis5_path : None
      exrootanalysis_path : None
                      OLP : MadLoop
                 applgrid : applgrid-config
               eps_viewer : None
                  fastjet : None
                 run_mode : 2
              web_browser : None
   automatic_html_opening : False
        cluster_temp_path : None
             cluster_size : 100
            cluster_queue : None
             syscalc_path : None
         madanalysis_path : None
                   lhapdf : /sps/atlas/m/muanza/MC/MADGRAPH/MG5_aMC_v3_0_1/HEPTools/lhapdf6/bin/lhapdf-config
             stdout_level : 20
                  nb_core : 32
            f2py_compiler : None
                    ninja : /sps/atlas/m/muanza/MC/MADGRAPH/MG5_aMC_v3_0_1/HEPTools/lib
include_lepton_initiated_processes : True
                  amcfast : amcfast-config
       cluster_retry_wait : 300
      output_dependencies : external
           crash_on_error : False
mg5amc_py8_interface_path : /sps/atlas/m/muanza/MC/MADGRAPH/MG5_aMC_v3_0_1/HEPTools/MG5aMC_PY8_interface
         loop_color_flows : False
                  samurai : None
         cluster_nb_retry : 1
                 mg5_path : /sps/atlas/m/muanza/MC/MADGRAPH/MG5_aMC_v3_0_1
                  timeout : 60
                    gauge : Feynman
      complex_mass_scheme : False
             cpp_compiler : None
   max_npoint_for_channel : 0

Is there something wrong in my setup? Does the NLO computation require massless quarks (when I don't force
them to the above values, I get a "division by zero" error message)?

Thanks
Regards, Steve

Question information

Language:
English Edit question
Status:
Solved
For:
MadGraph5_aMC@NLO Edit question
Assignee:
marco zaro Edit question
Solved by:
marco zaro
Solved:
2020-04-28
Last query:
2020-04-28
Last reply:
2020-04-28
marco zaro (marco-zaro) said : #1

Hi Steve,
there are a couple of problems in what you are trying to do. The most important one is that lepton-lepton collisions are not yet supported, as what is implemented now in MG5_aMC has a fixed c.o.m. energy but the FKS subtraction requires the change of the bjorken x's in order to work for initial-state singularities. The implementation of the electron structure functions is ongoing, but I cannot give any timeline for when it will be publicly available together with the possibility of performing EW corrections (while the inclusion of a convolution with the lepton luminosities is not a big issue per se, their particular shape requires lot of cares when they are integrated, in particular on the mapping of the event and counterevent).
The other problems is that, if in the model you load some particle has zero mass (like the b and c quarks), you must not set it !=0 in the param_card, otherwise you will get pole-miscancelation error or the IR checks will fail. Likewise, if you start with a model where a given particle is massive, you can set its mass to any value but not to zero.

I think these are the main issues, and unfortunately I fear I cannot help you much more...

Let me know if you have further questions.

Cheers,

Marco

Muanza (muanza) said : #2

Dear Marco,
Thank you for these explanations. I understand it's too early to try NLO-QED corrections in e+e-.
However, for s-channel production of quarks, the NLO-QCD corrections seems to work and don't require electron structure functions. I guess these are reliable, right?

Thanks
Regards, Steve

Best marco zaro (marco-zaro) said : #3

Hi Steve,
yes, as far as only QCD corrections are concerned, these work fine both in 3.x and in 2.x

There is also a quite comprehensive table in 1405.0301 documenting this.

Still, please be aware of what I said before about the values of the masses in the model.

Best wishes,

Marco

> On 28 Apr 2020, at 09:13, Muanza <email address hidden> wrote:
>
> Question #690249 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/690249
>
> Status: Answered => Open
>
> Muanza is still having a problem:
> Dear Marco,
> Thank you for these explanations. I understand it's too early to try NLO-QED corrections in e+e-.
> However, for s-channel production of quarks, the NLO-QCD corrections seems to work and don't require electron structure functions. I guess these are reliable, right?
>
> Thanks
> Regards, Steve
>
> --
> You received this question notification because you are assigned to this
> question.

Muanza (muanza) said : #4

Hello Marco,
Thank you, I'll remove the conflicting mass settings.

Regards, Steve