anomalous TGCs Whizard2

Dear Whizard expert,

I would like to simulate anomalous TGCs at 1.4 TeV for CLIC. I would like to validate my analysis at generation level at 1 TeV by comparing the variation for delata_gz1=+0.01 and delata_gz1=-0.01 with the case of SM, delata_gz1=0. However the variation is very small compared to the similar analysis at 1 TeV from ILC group(https://doi.org/10.1016/j.nuclphysbps.2015.09.362). Please find below the sindarin script that I am using. I wonder if there is anything wrong which reduces the variation in my script. I am using Whizard 2.8.2.

#---------------------
! Model and Process block
model = SM_ac_CKM

me = 0
mmu = 0
mtau = 0
ms = 0
mc = 0
mb = 0
mtop = 174 GeV
wtop = 1.37 GeV
mW = 80.45 GeV
wW = 2.071 GeV
mZ = 91.188 GeV
wZ = 2.478 GeV
mH = 125 GeV
wH = 0.00407 GeV

! anomalous couplings
g1z = 1.01
ka = 1
la = 0

! remove overlap with higher multiplicities
alphas = 0

alias q = u:d:s:c:b
alias qbar = U:D:S:C:B
alias lep = e1:e2:e3:E1:E2:E3
alias neutrino = n1:n2:n3:N1:N2:N3

! Beam block
sqrts = 1000 GeV

process decay_proc = e1, E1 => q, qbar, lep, neutrino

! circe2 beam spectrum and ISR
beams = e1, E1 => circe2 => isr
?keep_beams = true
?isr_handler = true
$isr_handler_mode = "recoil"
isr_alpha = 0.0072993
isr_mass = 0.000511

$circe2_file = "/cvmfs/clicdp.cern.ch/software/WHIZARD/circe_files/ILC/1000_B1b_ws_ee018.circe"
$circe2_design = "ILC"
?circe2_polarized = false

! Cuts block
real default_jet_cut = 10 GeV
cuts = all M > default_jet_cut [q,qbar] and all M > 4 GeV [lep, neutrino] and all M < 100 GeV [q,qbar] and all M < 100 GeV [lep, neutrino] and all Theta > 10 degree [lep] and all Theta < 170 degree [lep] and let subevt @WW = collect[colored:lep:neutrino] in all M > 1000 GeV [@WW]

#the m(qq),m(lnu)<100GeV cut removes the single W contribution

! Parton shower and hadronization

?ps_fsr_active = true
?ps_isr_active = false
?hadronization_active = true
$shower_method = "PYTHIA6"

$ps_PYTHIA_PYGIVE = "MSTJ(28)=0; PMAS(25,1)=120.; PMAS(25,2)=0.3605E-02; MSTJ(41)=2; MSTU(22)=2000; PARJ(21)=0.40000; PARJ(41)=0.11000; PARJ(42)=0.52000; PARJ(81)=0.25000; PARJ(82)=1.90000; MSTJ(11)=3; PARJ(54)=-0.03100; PARJ(55)=-0.00200; PARJ(1)=0.08500; PARJ(3)=0.45000; PARJ(4)=0.02500; PARJ(2)=0.31000; PARJ(11)=0.60000; PARJ(12)=0.40000; PARJ(13)=0.72000; PARJ(14)=0.43000; PARJ(15)=0.08000; PARJ(16)=0.08000; PARJ(17)=0.17000; MSTP(3)=1;MSTP(71)=1"

integrate (decay_proc) {iterations = 10:50000:"gw", 5:50000:""}
show(results)

n_events = 10000

sample_format = stdhep, ascii
$extension_stdhep = "stdhep"

simulate (decay_proc) {}
#------------------------

Many thanks in advance for your helps,
Feno