Default dynamical scale choice is crashing

Hi,

I have implemented a Feynrules model where beyond the SM appear 3 new particles, called "etameson", "chimeson" and "upsmeson". I do

generate p p > etameson chimeson, etameson > b b~, chimeson > e- e+ mu- mu+ QED=1 @1 (***)
add process p p > etameson chimeson j, etameson > b b~, chimeson > e- e+ mu- mu+ QED=1 @2

To clarify what I am doing, the leading process (***) is shown in the diagram here: https://www.dropbox.com/s/zqr79qhct6e5hsg/matrix1.ps.pdf?dl=0 . Note that there is a BSM 4-particle coupling [etameson-upsmeson-electron-positron] that takes part in the amplitude. When I launch the computation, it crashes and prints to screen the text reported at the end of this message.

I think I know the source of the problem: as discussed already in questions #1807699 and #676416, it is due to the fact that MGaMC introduces a fake particle (with PDG code 7) in order to be able to perform the phase-space integration, but such technique is not compatible with the default scale choice for mur and muf (i.e. dynamical_scale_choice = -1 in run_card). The recommended fix in those other questions, was to make a different choice for the scales, and indeed taking dynamical_scale_choice = 3 solves the issue for me when I consider the leading order process (***) alone. But now I want to generate a sample with MLM jet merging as above, and in this case I always get the error, for all scale choices (I tried all the dynamical ones: -1, 1, 2, 3, 4 as well as the fixed ones). This happens both in versions 2.6.4 and 2.6.5.

Is there a way that this problem can be circumvented?

Thank you,

Ennio

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* M A D G R A P H 5 _ a M C @ N L O *
* M A D E V E N T *
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* VERSION 2.6.5 2018-02-03 *
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* The MadGraph5_aMC@NLO Development Team - Find us at *
* https://server06.fynu.ucl.ac.be/projects/madgraph *
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* Type 'help' for in-line help. *
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************************************************************
INFO: load configuration from /Users/enniosalvioni/Documents/MG5_aMC_v2_6_4/bin/Zdecays_pp_new3_matched/Cards/me5_configuration.txt
INFO: load configuration from /Users/enniosalvioni/Documents/MG5_aMC_v2_6_4/input/mg5_configuration.txt
INFO: load configuration from /Users/enniosalvioni/Documents/MG5_aMC_v2_6_4/bin/Zdecays_pp_new3_matched/Cards/me5_configuration.txt
Using default text editor "vi". Set another one in ./input/mg5_configuration.txt
generate_events run_01
The following switches determine which programs are run:
/=================== Description ===================|================== values ===================|======== other options ========\
| 1. Choose the shower/hadronization program | shower = Pythia8 | OFF |
| 2. Choose the detector simulation program | detector = Delphes | OFF |
| 3. Choose an analysis package (plot/convert) | analysis = MadAnalysis5 | OFF|ExRoot |
| 4. Decay onshell particles | madspin = OFF | ON|onshell |
| 5. Add weights to events for new hypp. | reweight = Not Avail. | Please install module |
\=================================================================================================================================/
Either type the switch number (1 to 5) to change its setting,
Set any switch explicitly (e.g. type 'shower=OFF' at the prompt)
Type 'help' for the list of all valid option
Type '0', 'auto', 'done' or just press enter when you are done.[60s to answer]
>done
Do you want to edit a card (press enter to bypass editing)?
/------------------------------------------------------------\
| 1. param : param_card.dat |
| 2. run : run_card.dat |
| 3. pythia8 : pythia8_card.dat |
| 4. delphes : delphes_card.dat |
| 5. madanalysis5_parton : madanalysis5_parton_card.dat |
| 6. madanalysis5_hadron : madanalysis5_hadron_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, pythia8, 4, enter path, ... ][90s to answer]
>done
INFO: Update the dependent parameter of the param_card.dat
Generating 10000 events with run name run_01
survey run_01
INFO: compile directory
compile Source Directory
Using random number seed offset = 153
INFO: Running Survey
Creating Jobs
Working on SubProcesses
INFO: P2_gq_etamesonchimesonq_etameson_bbx_chimeson_llll
INFO: P2_qq_etamesonchimesong_etameson_bbx_chimeson_llll
STOP 3
rm: results.dat: No such file or directory
ERROR DETECTED
STOP 3
rm: results.dat: No such file or directory
ERROR DETECTED
INFO: P1_qq_etamesonchimeson_etameson_bbx_chimeson_llll
STOP 3
rm: results.dat: No such file or directory
ERROR DETECTED
STOP 3
rm: results.dat: No such file or directory
ERROR DETECTED
INFO: Idle: 1, Running: 0, Completed: 2 [ current time: 11h07 ]
INFO: Idle: 0, Running: 1, Completed: 2 [ current time: 11h07 ]
STOP 3
rm: results.dat: No such file or directory
ERROR DETECTED
INFO: Idle: 0, Running: 0, Completed: 3 [ 0.18s ]
INFO: End survey
refine 10000
Creating Jobs
INFO: Refine results to 10000
INFO: Generating 10000.0 unweigthed events.
Error when reading /Users/enniosalvioni/Documents/MG5_aMC_v2_6_4/bin/Zdecays_pp_new3_matched/SubProcesses/P2_gq_etamesonchimesonq_etameson_bbx_chimeson_llll/G1/results.dat
Command "generate_events run_01" interrupted with error:
Exception : Reported error: End code 3.0
  Full associated log:
  Process in group number 2
  A PDF is used, so alpha_s(MZ) is going to be modified
  Old value of alpha_s from param_card: 0.11839999999999999
   ****************************************

        NNPDFDriver version 1.0.3
    Grid: NNPDF23_lo_as_0130_qed_mem0.grid
   ****************************************
  New value of alpha_s from PDF nn23lo1: 0.13000000000000000
  Warning! ptj set to xqcut= 30.000000000000000 to improve integration efficiency
  Note that this might affect non-radiated jets,
  e.g. from decays. Use cut_decays=F in run_card.
  Warning! mmjj set to xqcut= 30.000000000000000 to improve integration efficiency
  Note that this might affect non-radiated jets,
  e.g. from decays. Use cut_decays=F in run_card.
  Define smin to 900.00000000000000
  Define smin to 900.00000000000000
  Define smin to 900.00000000000000
  Define smin to 900.00000000000000
  *****************************************************
  * MadGraph/MadEvent *
  * -------------------------------- *
  * http://madgraph.hep.uiuc.edu *
  * http://madgraph.phys.ucl.ac.be *
  * http://madgraph.roma2.infn.it *
  * -------------------------------- *
  * *
  * PARAMETER AND COUPLING VALUES *
  * *
  *****************************************************

   External Params
   ---------------------------------

  aEWM1 = 127.90000000000001
  mdl_Gf = 1.1663700000000000E-005
  aS = 0.11839999999999999
  mdl_ymb = 4.7000000000000002
  mdl_ymt = 173.00000000000000
  mdl_ymtau = 1.7769999999999999
  mdl_gZce = 7.0000000000000001E-003
  mdl_gbbe = 1.0000000000000001E-005
  mdl_Lcuff = 1.0000000000000000E-002
  mdl_vmu = 0.0000000000000000
  mdl_amu = -2.0000000000000002E-005
  mdl_MZ = 91.187600000000003
  mdl_MTA = 1.7769999999999999
  mdl_MT = 173.00000000000000
  mdl_MB = 4.7000000000000002
  mdl_MH = 125.00000000000000
  mdl_Mchi = 30.000000000000000
  mdl_Meta = 24.000000000000000
  mdl_Mups = 25.000000000000000
  mdl_WZ = 2.4952000000000001
  mdl_WW = 2.0850000000000000
  mdl_WT = 1.5083359999999999
  mdl_WH = 4.0699999999999998E-003
  mdl_Wchi = 1.0000000000000000E-004
  mdl_Weta = 1.0000000000000000E-004
  mdl_Wups = 1.0000000000000000E-004
   Internal Params
   ---------------------------------

  mdl_MZ__exp__2 = 8315.1783937600012
  mdl_MZ__exp__4 = 69142191.720053151
  mdl_sqrt__2 = 1.4142135623730951
  mdl_MH__exp__2 = 15625.000000000000
  mdl_complexi = (0.0000000000000000,1.0000000000000000)
  mdl_aEW = 7.8186082877247844E-003
  mdl_MW = 79.824359746197842
  mdl_sqrt__aEW = 8.8422894590285753E-002
  mdl_ee = 0.31345100004952897
  mdl_MW__exp__2 = 6371.9284088904105
  mdl_sw2 = 0.23369913342182447
  mdl_cw = 0.87538612427783857
  mdl_sqrt__sw2 = 0.48342438232036300
  mdl_sw = 0.48342438232036300
  mdl_g1 = 0.35807170271074895
  mdl_gw = 0.64839716719502682
  mdl_vev = 246.22056907348590
  mdl_vev__exp__2 = 60624.568634871241
  mdl_lam = 0.12886689630821144
  mdl_yb = 2.6995322804122722E-002
  mdl_yt = 0.99365762661983625
  mdl_ytau = 1.0206529494239589E-002
  mdl_muH = 88.388347648318444
  mdl_ee__exp__2 = 9.8251529432049817E-002
  mdl_sw__exp__2 = 0.23369913342182450
  mdl_cw__exp__2 = 0.76630086657817542
   Internal Params evaluated point by point
   ----------------------------------------

  mdl_sqrt__aS = 0.34409301068170506
  mdl_G__exp__2 = 1.4878582807401259
   Couplings of Zdecays9_UFO
   ---------------------------------

          GC_8 = 0.00000E+00 0.12198E+01
         GC_20 = 0.00000E+00 0.57700E-01
         GC_21 = -0.00000E+00 -0.11540E+00
         GC_23 = -0.00000E+00 -0.31265E+00
         GC_24 = 0.00000E+00 0.25495E+00
          GC_1 = 0.00000E+00 0.20000E-04
         GC_10 = -0.10000E-04 0.00000E+00
         GC_11 = 0.70000E-02 0.00000E+00
         GC_13 = 0.00000E+00 0.12026E-05
         GC_31 = 0.00000E+00 0.00000E+00

  Collider parameters:
  --------------------

  Running at P P machine @ 13000.000000000000 GeV
  PDF set = nn23lo1
  alpha_s(Mz)= 0.1300 running at 2 loops.
  alpha_s(Mz)= 0.1300 running at 2 loops.
  Renormalization scale fixed @ 91.188000000000002
  Factorization scales fixed @ 91.188000000000002 91.188000000000002

  getting user params
 Enter number of events and max and min iterations:
  Number of events and iterations 1000 5 3
 Enter desired fractional accuracy:
  Desired fractional accuracy: 0.10000000000000001
 Enter 0 for fixed, 2 for adjustable grid:
 Suppress amplitude (0 no, 1 yes)?
  Using suppressed amplitude.
 Exact helicity sum (0 yes, n = number/event)?
  Explicitly summing over helicities
 Enter Configuration Number:
 Running Configuration Number: 1
  Not subdividing B.W.
  Attempting mappinvarients 1 9
  Completed mapping 9
  about to integrate 19 1000 5 3 19 1
  Using non-zero grid deformation.
  19 dimensions 1000 events 19 invarients 5 iterations 1 config(s), (0.99)
  Using h-tuple random number sequence.
  Error opening grid
  Using Uniform Grid! 36
  Using uniform alpha 1.0000000000000000
  Grid defined OK
  Set CM energy to 13000.00
  Mapping Graph 1 to config 1
  Setting BW -1 1 25.000000000000000
 Setting grid 2 0.59172E-08 1
  Setting BW -3 2 30.000000000000000
  Setting BW -4 3 24.000000000000000
  Setting BW -5 4 91.187600000000003
 Setting grid 6 0.17253E-04 1
  Transforming s_hat 1/s 18 4.1748497094674567E-005 900.00000000000000 168999999.99999997
    1 1 2 3 4 5 6 7 8 9 10 11 12 13 14
   15 16 17 18 19
  Masses: 0.000E+00 0.000E+00 0.470E+01 0.470E+01 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00
 Using random seed offsets 1 : 1
   with seed 156
  Ranmar initialization seeds 11481 9536

  ********************************************
  * You are using the DiscreteSampler module *
  * part of the MG5_aMC framework *
  * Author: Valentin Hirschi *
  ********************************************

   Particle 3 4 5 6 7 8 9
       Et > 0.0 0.0 0.0 0.0 0.0 0.0 30.0
        E > 0.0 0.0 0.0 0.0 0.0 0.0 0.0
      Eta < -1.0 -1.0 -1.0 -1.0 -1.0 -1.0 5.0
    xqcut: 0.0 0.0 0.0 0.0 0.0 0.0 30.0
 d R # 3 > -0.0 0.0 0.0 0.0 0.0 0.0 0.0
 d R # 4 > -0.0 -0.0 0.0 0.0 0.0 0.0 0.0
 d R # 5 > -0.0 -0.0 -0.0 0.0 0.0 0.0 0.0
 d R # 6 > -0.0 -0.0 -0.0 -0.0 0.0 0.0 0.0
 d R # 7 > -0.0 -0.0 -0.0 -0.0 -0.0 0.0 0.0
 d R # 8 > -0.0 -0.0 -0.0 -0.0 -0.0 -0.0 0.0
 s min # 3> 0.0 0.0 0.0 0.0 0.0 0.0 0.0
 s min # 4> 0.0 0.0 0.0 0.0 0.0 0.0 0.0
 s min # 5> 0.0 0.0 0.0 0.0 0.0 0.0 0.0
 s min # 6> 0.0 0.0 0.0 0.0 0.0 0.0 0.0
 s min # 7> 0.0 0.0 0.0 0.0 0.0 0.0 0.0
 s min # 8> 0.0 0.0 0.0 0.0 0.0 0.0 0.0
 xqcutij # 3> 0.0 0.0 0.0 0.0 0.0 0.0 0.0
 xqcutij # 4> 0.0 0.0 0.0 0.0 0.0 0.0 0.0
 xqcutij # 5> 0.0 0.0 0.0 0.0 0.0 0.0 0.0
 xqcutij # 6> 0.0 0.0 0.0 0.0 0.0 0.0 0.0
 xqcutij # 7> 0.0 0.0 0.0 0.0 0.0 0.0 0.0
 xqcutij # 8> 0.0 0.0 0.0 0.0 0.0 0.0 0.0
  No cut BW -1 1
  No cut BW -3 2
  No cut BW -4 3
  No cut BW -5 4
            7 > -11 9000007 color 2 > 1 1
  failed for ipartupdate. Please retry without MLM/default dynamical scale
 STOP 3

 ls status:
 input_app.txt
 log.txt
 run1_app.log

Please report this bug on https://bugs.launchpad.net/mg5amcnlo
More information is found in '/Users/enniosalvioni/Documents/MG5_aMC_v2_6_4/bin/Zdecays_pp_new3_matched/run_01_tag_1_debug.log'.
Please attach this file to your report.
INFO:
quit
INFO:

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