MadGraph5_aMC@NLO

Pythia6Q shower @100tev

Asked by Michele Selvaggi

Hi guys,

I am trying to generate p p > t t~ events at NLO at 100 tev with pythia6q shower and the generation crashes (*).
I am using the last version MG5_aMC_2_2_1 and the default run_card and parameter _card (just changing ECM and shower)
It seems that the program is failing due to some problems with PDFs.
I would like to simply compare Herwig and Pythia6 shower, but leaving the rest unchanged.

Can you suggest some fix?

Thanks,
Michele

(*) Error:

----------------------------------------------------
INFO: P0_uux_ttx done.
INFO: P0_uxu_ttx done.
Exception AttributeError: AttributeError("'_DummyThread' object has no attribute '_Thread__block'",) in <module 'threading' from '/nfs/soft/python/python-2.7.3-sl5_amd64_gcc41/lib/python2.7/threading.pyo'> ignored
Exception AttributeError: AttributeError("'_DummyThread' object has no attribute '_Thread__block'",) in <module 'threading' from '/nfs/soft/python/python-2.7.3-sl5_amd64_gcc41/lib/python2.7/threading.pyo'> ignored
INFO: P0_gg_ttx done.
INFO: Checking test output:
INFO: P0_gg_ttx
INFO: Result for test_ME:
INFO: Passed.
INFO: Result for test_MC:
INFO: Output of the failing test:
 Enter the Monte Carlo name: possible choices are
 HERWIG6, HERWIGPP, PYTHIA6Q, PYTHIA6PT, PYTHIA8
 Enter 0 to compute MC/MC(limit)
       1 to compute MC/ME(limit)
 Enter alpha, beta for G_soft
   Enter alpha<0 to set G_soft=1 (no ME soft)
 Enter alpha, beta for G_azi
   Enter alpha>0 to set G_azi=0 (no azi corr)
 Enter xi_i, y_ij to be used in coll/soft tests
  Enter -2 to generate them randomly
 Enter number of tests for soft and collinear limits
 Sum over helicity (0), or random helicity (1)

 ****************************************************
 ****************************************************
             Testing limits for PYTHIA6Q
 ****************************************************
 ****************************************************

 A PDF is used, so alpha_s(MZ) is going to be modified
 Old value of alpha_s from param_card: 0.11799999999999999
  ****************************************

       NNPDFDriver version 1.0.3
   Grid: NNPDF23nlo_as_0119_qed_mem0.grid
  ****************************************
 New value of alpha_s from PDF nn23nlo: 0.11899999999999999
 Give FKS configuration number ("0" loops over all)

 =================================================

 NEW FKS CONFIGURATION:
 FKS configuration number is 1
 FKS partons are: i= 5 j= 1
 with PDGs: i= 21 j= 21

 Enter graph number (iconfig), '0' loops over all graphs
Using random seed offsets: 0 , 1 , 0
  with seed 34
 Ranmar initialization seeds 13167 9409
nFKSprocess: 1. Absolute lower bound for tau at the Born is 0.11972E-04 0.34600E+03 0.10000E+06
nFKSprocess: 1. Lower bound for tau is 0.11972E-04 0.34600E+03 0.10000E+06
nFKSprocess: 1. Lower bound for tau is (taking resonances into account) 0.11972E-04 0.34600E+03 0.10000E+06
nFKSprocess: 2. Absolute lower bound for tau at the Born is 0.11972E-04 0.34600E+03 0.10000E+06
nFKSprocess: 2. Lower bound for tau is 0.11972E-04 0.34600E+03 0.10000E+06
nFKSprocess: 2. Lower bound for tau is (taking resonances into account) 0.11972E-04 0.34600E+03 0.10000E+06
nFKSprocess: 3. Absolute lower bound for tau at the Born is 0.11972E-04 0.34600E+03 0.10000E+06
nFKSprocess: 3. Lower bound for tau is (taking resonances into account) 0.11972E-04 0.34600E+03 0.10000E+06
nFKSprocess: 4. Absolute lower bound for tau at the Born is 0.11972E-04 0.34600E+03 0.10000E+06
nFKSprocess: 4. Lower bound for tau is (taking resonances into account) 0.11972E-04 0.34600E+03 0.10000E+06
nFKSprocess: 5. Absolute lower bound for tau at the Born is 0.11972E-04 0.34600E+03 0.10000E+06
nFKSprocess: 5. Lower bound for tau is 0.11972E-04 0.34600E+03 0.10000E+06
nFKSprocess: 5. Lower bound for tau is (taking resonances into account) 0.11972E-04 0.34600E+03 0.10000E+06
nFKSprocess: 6. Absolute lower bound for tau at the Born is 0.11972E-04 0.34600E+03 0.10000E+06
nFKSprocess: 6. Lower bound for tau is 0.11972E-04 0.34600E+03 0.10000E+06
nFKSprocess: 6. Lower bound for tau is (taking resonances into account) 0.11972E-04 0.34600E+03 0.10000E+06
nFKSprocess: 7. Absolute lower bound for tau at the Born is 0.11972E-04 0.34600E+03 0.10000E+06
nFKSprocess: 7. Lower bound for tau is 0.11972E-04 0.34600E+03 0.10000E+06
nFKSprocess: 7. Lower bound for tau is (taking resonances into account) 0.11972E-04 0.34600E+03 0.10000E+06
nFKSprocess: 8. Absolute lower bound for tau at the Born is 0.11972E-04 0.34600E+03 0.10000E+06
nFKSprocess: 8. Lower bound for tau is 0.11972E-04 0.34600E+03 0.10000E+06
nFKSprocess: 8. Lower bound for tau is (taking resonances into account) 0.11972E-04 0.34600E+03 0.10000E+06

 Soft tests done for (Born) config 1
 Failures: 0
     Soft test 1 PASSED. Fraction of failures: 0.00

 Collinear tests done for (Born) config 1
 Failures: 50
Collinear test 1 FAILED. Fraction of failures: 0.50

 =================================================

 NEW FKS CONFIGURATION:
 FKS configuration number is 2
 FKS partons are: i= 5 j= 2
 with PDGs: i= 21 j= 21

 Enter graph number (iconfig), '0' loops over all graphs

 Soft tests done for (Born) config 1
 Failures: 0
     Soft test 2 PASSED. Fraction of failures: 0.00

 Collinear tests done for (Born) config 1
 Failures: 50
Collinear test 2 FAILED. Fraction of failures: 0.50

 =================================================

 NEW FKS CONFIGURATION:
 FKS configuration number is 3
 FKS partons are: i= 5 j= 3
 with PDGs: i= 21 j= 6

 Enter graph number (iconfig), '0' loops over all graphs

 Soft tests done for (Born) config 1
 Failures: 0
     Soft test 3 PASSED. Fraction of failures: 0.00

 No collinear test for massive j_fks

 =================================================

 NEW FKS CONFIGURATION:
 FKS configuration number is 4
 FKS partons are: i= 5 j= 4
 with PDGs: i= 21 j= -6

 Enter graph number (iconfig), '0' loops over all graphs

 Soft tests done for (Born) config 1
 Failures: 0
     Soft test 4 PASSED. Fraction of failures: 0.00

 No collinear test for massive j_fks

 =================================================

 NEW FKS CONFIGURATION:
 FKS configuration number is 5
 FKS partons are: i= 5 j= 1
 with PDGs: i= -1 j= -1

 Enter graph number (iconfig), '0' loops over all graphs

 Soft tests done for (Born) config 1
 Failures: 0
     Soft test 5 PASSED. Fraction of failures: 0.00

 Collinear tests done for (Born) config 1
 Failures: 51
Collinear test 5 FAILED. Fraction of failures: 0.51

 =================================================

 NEW FKS CONFIGURATION:
 FKS configuration number is 6
 FKS partons are: i= 5 j= 1
 with PDGs: i= 1 j= 1

 Enter graph number (iconfig), '0' loops over all graphs

 Soft tests done for (Born) config 1
 Failures: 0
     Soft test 6 PASSED. Fraction of failures: 0.00

 Collinear tests done for (Born) config 1
 Failures: 58
Collinear test 6 FAILED. Fraction of failures: 0.58

 =================================================

 NEW FKS CONFIGURATION:
 FKS configuration number is 7
 FKS partons are: i= 5 j= 2
 with PDGs: i= -1 j= -1

 Enter graph number (iconfig), '0' loops over all graphs

 Soft tests done for (Born) config 1
 Failures: 0
     Soft test 7 PASSED. Fraction of failures: 0.00

 Collinear tests done for (Born) config 1
 Failures: 59
Collinear test 7 FAILED. Fraction of failures: 0.59

 =================================================

 NEW FKS CONFIGURATION:
 FKS configuration number is 8
 FKS partons are: i= 5 j= 2
 with PDGs: i= 1 j= 1

 Enter graph number (iconfig), '0' loops over all graphs

 Soft tests done for (Born) config 1
 Failures: 0
     Soft test 8 PASSED. Fraction of failures: 0.00

 Collinear tests done for (Born) config 1
 Failures: 61
Collinear test 8 FAILED. Fraction of failures: 0.61
Error detected in "launch auto "
write debug file /nfs/user/mselvaggi/MG5_aMC_v2_2_1/tt_nlo_py/run_03_tag_1_debug.log
If you need help with this issue please contact us on https://answers.launchpad.net/madgraph5
aMCatNLOError : Some tests failed, run cannot continue.
 Please check that widths of final state particles (e.g. top) have been set to 0 in the param_card.dat.

Question information

Language:
English Edit question
Status:
Answered
For:
MadGraph5_aMC@NLO Edit question
Assignee:
Rikkert Frederix Edit question
Last query:
Last reply:
Revision history for this message
Paolo Torrielli (paolo-torrielli) said : 		#1

Hi Michele,
thanks for spotting this problem out.
The issue was due to a small bug in the testing routine, related to an improper setting of a shower boundary condition.
The following patch should solve it:

=== modified file 'Template/NLO/SubProcesses/symmetry_fks_test_MC.f'
--- Template/NLO/SubProcesses/symmetry_fks_test_MC.f 2014-06-26 08:45:41 +0000
+++ Template/NLO/SubProcesses/symmetry_fks_test_MC.f 2014-10-06 16:07:28 +0000
@@ -144,6 +144,13 @@

       character*10 MonteCarlo
       common/cMonteCarloType/MonteCarlo
+
+ double precision shower_S_scale(fks_configs*2)
+ & ,shower_H_scale(fks_configs*2),ref_H_scale(fks_configs*2)
+ & ,pt_hardness
+ common /cshowerscale2/shower_S_scale,shower_H_scale,ref_H_scale
+ & ,pt_hardness
+
 c integer icomp
 c
 c DATA
@@ -371,6 +378,10 @@

          call set_cms_stuff(0)
          calculatedBorn=.false.
+
+c Initialise shower_S_scale to a large value, not to get spurious dead zones
+ shower_S_scale=1d20
+
          if(ilim.eq.0)then
            call xmcsubt_wrap(p1_cnt(0,1,0),zero,y_ij_fks_ev,fxl)
          else

Let me know if it works.
Cheers.
Paolo

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