" KeyError : 'loop' " when generating events with a model restriction

Dear MG5 experts,

I wrote a model containing the four-light quark operators in the SMEFT (SM4LQatNLO_MFV) and then restricted it to one operator, but when I try to launch the event generation (at LO), I get the following error (log file below):

INFO: Update the dependent parameter of the param_card.dat
Generating 200000 events with run name run_01
survey run_01
INFO: compile directory
INFO: Using LHAPDF v6.3.0 interface for PDFs
write compile file for card: /home/matteo/Desktop/MG5_aMC_v3_1_0/bin/pp_lvjj/int_cuu_lo/Cards/param_card.dat
Command "generate_events run_01" interrupted with error:
KeyError : 'loop'

I am not sure about what the problem is with the model, can you give me some hints?

This only happens when I use the restriction; I also tried to generate the process (p p > l+ vl j j QCD=2 NP^2==2) with all the operators switched on, but I am getting back a "Survey return zero cross section" error.
I read the FAQ-General-14 (https://cp3.irmp.ucl.ac.be/projects/madgraph/wiki/FAQ-General-14) and I don't think any of the typical reasons causes the problem, so maybe it's be related to the 4-point interaction among light quarks: what do you think?

Cheers,

Matteo

Anyway, here's the log file:

generate_events run_01
Traceback (most recent call last):
  File "/home/matteo/Desktop/MG5_aMC_v3_1_0/madgraph/interface/extended_cmd.py", line 1544, in onecmd
    return self.onecmd_orig(line, **opt)
  File "/home/matteo/Desktop/MG5_aMC_v3_1_0/madgraph/interface/extended_cmd.py", line 1493, in onecmd_orig
    return func(arg, **opt)
  File "/home/matteo/Desktop/MG5_aMC_v3_1_0/madgraph/interface/madevent_interface.py", line 2474, in do_generate_events
    self.run_generate_events(switch_mode, args)
  File "/home/matteo/Desktop/MG5_aMC_v3_1_0/madgraph/interface/common_run_interface.py", line 7114, in new_fct
    original_fct(obj, *args, **opts)
  File "/home/matteo/Desktop/MG5_aMC_v3_1_0/madgraph/interface/madevent_interface.py", line 2513, in run_generate_events
    self.exec_cmd('survey %s %s' % (self.run_name,' '.join(args)),
  File "/home/matteo/Desktop/MG5_aMC_v3_1_0/madgraph/interface/extended_cmd.py", line 1573, in exec_cmd
    stop = Cmd.onecmd_orig(current_interface, line, **opt)
  File "/home/matteo/Desktop/MG5_aMC_v3_1_0/madgraph/interface/extended_cmd.py", line 1493, in onecmd_orig
    return func(arg, **opt)
  File "/home/matteo/Desktop/MG5_aMC_v3_1_0/madgraph/interface/madevent_interface.py", line 3332, in do_survey
    self.configure_directory()
  File "/home/matteo/Desktop/MG5_aMC_v3_1_0/madgraph/interface/madevent_interface.py", line 5732, in configure_directory
    self.do_treatcards('')
  File "/home/matteo/Desktop/MG5_aMC_v3_1_0/madgraph/interface/madevent_interface.py", line 3102, in do_treatcards
    param_card.write_inc_file(outfile, ident_card, default, need_mp=need_mp)
  File "/home/matteo/Desktop/MG5_aMC_v3_1_0/models/check_param_card.py", line 648, in write_inc_file
    value =defaultcard[block].get(tuple(lhaid)).value
  File "/home/matteo/Desktop/MG5_aMC_v3_1_0/models/check_param_card.py", line 403, in __getitem__
    return dict.__getitem__(self,name.lower())
KeyError: 'loop'
                              Run Options
                              -----------
               stdout_level : 10 (user set)

                         MadEvent Options
                         ----------------
     automatic_html_opening : False (user set)
        notification_center : True
                   run_mode : 2
              cluster_queue : None (user set)
               cluster_time : None (user set)
               cluster_size : 100
             cluster_memory : 100 (user set)
                    nb_core : 8 (user set)
          cluster_temp_path : None

                      Configuration Options
                      ---------------------
               pythia8_path : /home/matteo/Desktop/MG5_aMC_v3_1_0/HEPTools/pythia8 (user set)
                  hwpp_path : None (user set)
                thepeg_path : None (user set)
                 hepmc_path : None (user set)
           madanalysis_path : None (user set)
          madanalysis5_path : /home/matteo/Desktop/MG5_aMC_v3_1_0/HEPTools/madanalysis5/madanalysis5 (user set)
            pythia-pgs_path : None (user set)
                    td_path : None (user set)
               delphes_path : None (user set)
        exrootanalysis_path : None (user set)
               syscalc_path : None (user set)
                     lhapdf : /home/matteo/Desktop/MG5_aMC_v3_1_0/HEPTools/lhapdf6_py3/bin/lhapdf-config (user set)
                 lhapdf_py2 : None
                 lhapdf_py3 : /home/matteo/Desktop/MG5_aMC_v3_1_0/HEPTools/lhapdf6_py3/bin/lhapdf-config (user set)
                    timeout : 60
              f2py_compiler : None
          f2py_compiler_py2 : None
          f2py_compiler_py3 : None
                web_browser : None
                 eps_viewer : None
                text_editor : None
           fortran_compiler : None
               cpp_compiler : None
                auto_update : 7 (user set)
               cluster_type : condor
      cluster_status_update : (600, 30)
           cluster_nb_retry : 1
         cluster_local_path : None
         cluster_retry_wait : 300

PROC_CARD:

set group_subprocesses Auto
set ignore_six_quark_processes False
set low_mem_multicore_nlo_generation False
set complex_mass_scheme False
set include_lepton_initiated_processes False
set gauge unitary
set loop_optimized_output True
set loop_color_flows False
set max_npoint_for_channel 0
set default_unset_couplings 99
set max_t_for_channel 99
set zerowidth_tchannel True
set nlo_mixed_expansion True
import model sm
define p = g u c d s u~ c~ d~ s~
define j = g u c d s u~ c~ d~ s~
define l+ = e+ mu+
define l- = e- mu-
define vl = ve vm vt
define vl~ = ve~ vm~ vt~
import model SM4LQatNLO_MFV-oneop
define p = 21 2 4 1 3 -2 -4 -1 -3 5 -5 # pass to 5 flavors
define j = p
generate p p > l+ vl j j QCD=2 NP^2==2
add process p p > l- vl~ j j QCD=2 NP^2==2
output pp_lvjj/int_cuu_lo

PARAM_CARD:

###################################
## INFORMATION FOR MASS
###################################
Block mass
    6 1.720000e+02 # MT
   23 9.118760e+01 # MZ
   25 1.250000e+02 # MH
## Dependent parameters, given by model restrictions.
## Those values should be edited following the
## analytical expression. MG5 ignores those values
## but they are important for interfacing the output of MG5
## to external program such as Pythia.
  1 0.000000e+00 # d : 0.0
  2 0.000000e+00 # u : 0.0
  3 0.000000e+00 # s : 0.0
  4 0.000000e+00 # c : 0.0
  5 0.000000e+00 # b : 0.0
  11 0.000000e+00 # e- : 0.0
  12 0.000000e+00 # ve : 0.0
  13 0.000000e+00 # mu- : 0.0
  14 0.000000e+00 # vm : 0.0
  15 0.000000e+00 # ta- : 0.0
  16 0.000000e+00 # vt : 0.0
  21 0.000000e+00 # g : 0.0
  22 0.000000e+00 # a : 0.0
  24 7.982436e+01 # w+ : cmath.sqrt(MZ__exp__2/2. + cmath.sqrt(MZ__exp__4/4. - (aEW*cmath.pi*MZ__exp__2)/(Gf*sqrt__2)))
  9000002 9.118760e+01 # ghz : MZ
  9000003 7.982436e+01 # ghwp : MW
  9000004 7.982436e+01 # ghwm : MW

###################################
## INFORMATION FOR SMEFT
###################################
Block smeft
    3 1.100000e+00 # cuu

###################################
## INFORMATION FOR SMEFTCUTOFF
###################################
Block smeftcutoff
    1 1.000000e+03 # LambdaSMEFT

###################################
## INFORMATION FOR SMINPUTS
###################################
Block sminputs
    1 1.279000e+02 # aEWM1
    2 1.166370e-05 # Gf
    3 1.184000e-01 # aS (Note that Parameter not used if you use a PDF set)

###################################
## INFORMATION FOR YUKAWA
###################################
Block yukawa
    6 1.720000e+02 # ymt

###################################
## INFORMATION FOR DECAY
###################################
DECAY 6 1.508336e+00 # WT
DECAY 23 2.495200e+00 # WZ
DECAY 24 2.085000e+00 # WW
DECAY 25 4.070000e-03 # WH
## Dependent parameters, given by model restrictions.
## Those values should be edited following the
## analytical expression. MG5 ignores those values
## but they are important for interfacing the output of MG5
## to external program such as Pythia.
DECAY 1 0.000000e+00 # d : 0.0
DECAY 2 0.000000e+00 # u : 0.0
DECAY 3 0.000000e+00 # s : 0.0
DECAY 4 0.000000e+00 # c : 0.0
DECAY 5 0.000000e+00 # b : 0.0
DECAY 11 0.000000e+00 # e- : 0.0
DECAY 12 0.000000e+00 # ve : 0.0
DECAY 13 0.000000e+00 # mu- : 0.0
DECAY 14 0.000000e+00 # vm : 0.0
DECAY 15 0.000000e+00 # ta- : 0.0
DECAY 16 0.000000e+00 # vt : 0.0
DECAY 21 0.000000e+00 # g : 0.0
DECAY 22 0.000000e+00 # a : 0.0
DECAY 9000002 2.495200e+00 # ghz : WZ
DECAY 9000003 2.085000e+00 # ghwp : WW
DECAY 9000004 2.085000e+00 # ghwm : WW
#===========================================================
# QUANTUM NUMBERS OF NEW STATE(S) (NON SM PDG CODE)
#===========================================================

Block QNUMBERS 9000001 # gha
        1 0 # 3 times electric charge
        2 1 # number of spin states (2S+1)
        3 1 # colour rep (1: singlet, 3: triplet, 8: octet)
        4 1 # Particle/Antiparticle distinction (0=own anti)
Block QNUMBERS 9000002 # ghz
        1 0 # 3 times electric charge
        2 1 # number of spin states (2S+1)
        3 1 # colour rep (1: singlet, 3: triplet, 8: octet)
        4 1 # Particle/Antiparticle distinction (0=own anti)
Block QNUMBERS 9000003 # ghwp
        1 3 # 3 times electric charge
        2 1 # number of spin states (2S+1)
        3 1 # colour rep (1: singlet, 3: triplet, 8: octet)
        4 1 # Particle/Antiparticle distinction (0=own anti)
Block QNUMBERS 9000004 # ghwm
        1 -3 # 3 times electric charge
        2 1 # number of spin states (2S+1)
        3 1 # colour rep (1: singlet, 3: triplet, 8: octet)
        4 1 # Particle/Antiparticle distinction (0=own anti)
Block QNUMBERS 82 # ghg
        1 0 # 3 times electric charge
        2 1 # number of spin states (2S+1)
        3 8 # colour rep (1: singlet, 3: triplet, 8: octet)
        4 1 # Particle/Antiparticle distinction (0=own anti)

RUN_CARD:

#*********************************************************************
# Tag name for the run (one word) *
#*********************************************************************
  tag_1 = run_tag ! name of the run
#*********************************************************************
# Number of events and rnd seed *
# Warning: Do not generate more than 1M events in a single run *
#*********************************************************************
  200000 = nevents ! Number of unweighted events requested
  0 = iseed ! rnd seed (0=assigned automatically=default))
#*********************************************************************
# Collider type and energy *
# lpp: 0=No PDF, 1=proton, -1=antiproton, 2=photon from proton, *
# 3=photon from electron, 4=photon from muon *
#*********************************************************************
     1 = lpp1 ! beam 1 type
     1 = lpp2 ! beam 2 type
     6500.0 = ebeam1 ! beam 1 total energy in GeV
     6500.0 = ebeam2 ! beam 2 total energy in GeV
# To see polarised beam options: type "update beam_pol"

#*********************************************************************
# PDF CHOICE: this automatically fixes also alpha_s and its evol. *
#*********************************************************************
     lhapdf = pdlabel ! PDF set
     260000 = lhaid ! if pdlabel=lhapdf, this is the lhapdf number
# To see heavy ion options: type "update ion_pdf"
#*********************************************************************
# Renormalization and factorization scales *
#*********************************************************************
 True = fixed_ren_scale ! if .true. use fixed ren scale
 True = fixed_fac_scale ! if .true. use fixed fac scale
 1000.0 = scale ! fixed ren scale
 1000.0 = dsqrt_q2fact1 ! fixed fact scale for pdf1
 1000.0 = dsqrt_q2fact2 ! fixed fact scale for pdf2
 -1 = dynamical_scale_choice ! Choose one of the preselected dynamical choices
 1.0 = scalefact ! scale factor for event-by-event scales
#*********************************************************************
# Type and output format
#*********************************************************************
  False = gridpack !True = setting up the grid pack
  -1.0 = time_of_flight ! threshold (in mm) below which the invariant livetime is not written (-1 means not written)
  average = event_norm ! average/sum. Normalization of the weight in the LHEF
# To see MLM/CKKW merging options: type "update MLM" or "update CKKW"

#*********************************************************************
#
#*********************************************************************
# Phase-Space Optimization strategy (basic options)
#*********************************************************************
   0 = nhel ! using helicities importance sampling or not.
                             ! 0: sum over helicity, 1: importance sampling
   2 = sde_strategy ! default integration strategy (hep-ph/2021.xxxxx)
                             ! 1 is old strategy (using amp square)
        ! 2 is new strategy (using only the denominator)
# To see advanced option for Phase-Space optimization: type "update psoptim"
#*********************************************************************
# Generation bias, check the wiki page below for more information: *
# 'cp3.irmp.ucl.ac.be/projects/madgraph/wiki/LOEventGenerationBias' *
#*********************************************************************
 None = bias_module ! Bias type of bias, [None, ptj_bias, -custom_folder-]
 {} = bias_parameters ! Specifies the parameters of the module.
#
#*******************************
# Parton level cuts definition *
#*******************************
#
#
#*********************************************************************
# BW cutoff (M+/-bwcutoff*Gamma) ! Define on/off-shell for "$" and decay
#*********************************************************************
  15.0 = bwcutoff ! (M+/-bwcutoff*Gamma)
#*********************************************************************
# Standard Cuts *
#*********************************************************************
# Minimum and maximum pt's (for max, -1 means no cut) *
#*********************************************************************
 30.0 = ptj ! minimum pt for the jets
 20.0 = ptl ! minimum pt for the charged leptons
 20.0 = misset ! minimum missing Et (sum of neutrino's momenta)
 -1.0 = ptjmax ! maximum pt for the jets
 -1.0 = ptlmax ! maximum pt for the charged leptons
 -1.0 = missetmax ! maximum missing Et (sum of neutrino's momenta)
 {} = pt_min_pdg ! pt cut for other particles (use pdg code). Applied on particle and anti-particle
 {} = pt_max_pdg ! pt cut for other particles (syntax e.g. {6: 100, 25: 50})
#
# For display option for energy cut in the partonic center of mass frame type 'update ecut'
#
#*********************************************************************
# Maximum and minimum absolute rapidity (for max, -1 means no cut) *
#*********************************************************************
 5.0 = etaj ! max rap for the jets
 2.4 = etal ! max rap for the charged leptons
 0.0 = etalmin ! main rap for the charged leptons
 {} = eta_min_pdg ! rap cut for other particles (use pdg code). Applied on particle and anti-particle
 {} = eta_max_pdg ! rap cut for other particles (syntax e.g. {6: 2.5, 23: 5})
#*********************************************************************
# Minimum and maximum DeltaR distance *
#*********************************************************************
 0.4 = drjj ! min distance between jets
 0.4 = drjl ! min distance between jet and lepton
 -1.0 = drjjmax ! max distance between jets
 -1.0 = drjlmax ! max distance between jet and lepton
#*********************************************************************
# Minimum and maximum invariant mass for pairs *
#*********************************************************************
 1000.0 = mmjj ! min invariant mass of a jet pair
 -1.0 = mmjjmax ! max invariant mass of a jet pair
 {} = mxx_min_pdg ! min invariant mass of a pair of particles X/X~ (e.g. {6:250})
 {'default': False} = mxx_only_part_antipart ! if True the invariant mass is applied only
                       ! to pairs of particle/antiparticle and not to pairs of the same pdg codes.
 #*********************************************************************
 # Minimum and maximum invariant mass for all letpons *
 #*********************************************************************
 0.0 = mmnl ! min invariant mass for all letpons (l+- and vl)
 -1.0 = mmnlmax ! max invariant mass for all letpons (l+- and vl)
 #*********************************************************************
 # Minimum and maximum pt for 4-momenta sum of leptons / neutrino *
 # for pair of lepton includes only same flavor, opposite charge
 #*********************************************************************
#*********************************************************************
# Inclusive cuts *
#*********************************************************************
 0.0 = xptj ! minimum pt for at least one jet
 #*********************************************************************
 # Control the pt's of the jets sorted by pt *
 #*********************************************************************
 50.0 = ptj1min ! minimum pt for the leading jet in pt
 0.0 = ptj2min ! minimum pt for the second jet in pt
 -1.0 = ptj1max ! maximum pt for the leading jet in pt
 -1.0 = ptj2max ! maximum pt for the second jet in pt
 0 = cutuse ! reject event if fails any (0) / all (1) jet pt cuts
 #*********************************************************************
 # Control the Ht(k)=Sum of k leading jets *
 #*********************************************************************
 0.0 = htjmin ! minimum jet HT=Sum(jet pt)
 -1.0 = htjmax ! maximum jet HT=Sum(jet pt)
 0.0 = ihtmin !inclusive Ht for all partons (including b)
 -1.0 = ihtmax !inclusive Ht for all partons (including b)
 #*********************************************************************
 # WBF cuts *
 #*********************************************************************
 0.0 = xetamin ! minimum rapidity for two jets in the WBF case
 2.0 = deltaeta ! minimum rapidity for two jets in the WBF case
#*********************************************************************
# maximal pdg code for quark to be considered as a light jet *
# (otherwise b cuts are applied) *
#*********************************************************************
 5 = maxjetflavor ! Maximum jet pdg code
#*********************************************************************
#
#*********************************************************************
# Store info for systematics studies *
# WARNING: Do not use for interference type of computation *
#*********************************************************************
   False = use_syst ! Enable systematics studies
#
none = systematics_program ! none, systematics [python], SysCalc [depreceted, C++]
['--mur=0.5,1,2', '--muf=0.5,1,2', '--pdf=errorset'] = systematics_arguments ! see: https://cp3.irmp.ucl.ac.be/projects/madgraph/wiki/Systematics#Systematicspythonmodule
# Syscalc is deprecated but to see the associate options type'update syscalc'