ws in stop decay not decaying

Asked by Rakhi Mahbubani

Hi, I'm trying to generate stop production and dileptonic decay directly in MG5 (banner card appended below), but the actual process generated only goes down to the ws, and doesn't decay the ws leptonically like I want. I don't think I'm running into the limit on the number of particles in the final state, but is there some limit to the number of steps you can ask for in a decay chain?

Cheers,

Rakhi

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# MadGraph 5 *
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# Going Beyond *
# *
# http://madgraph.hep.uiuc.edu *
# http://madgraph.phys.ucl.ac.be *
# http://madgraph.roma2.infn.it *
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# The MadGraph team *
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#....................................................................*
# *
# This file contains all the information necessary to reproduce *
# the events generated: *
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# 1. software version *
# 2. proc_card : code generation info including model *
# 3. param_card : model primary parameters in the LH format *
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<MGVersion>
# MG version : 5.1.4.6
# model version : usrmod_1.0.5
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<MG5ProcCard>
#************************************************************
#* MadGraph 5 *
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#* VERSION 1.4.6 2012-05-16 *
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#* *
#************************************************************
#* *
#* Command File for MadGraph 5 *
#* *
#* run as ./bin/mg5 filename *
#* *
#************************************************************
import model sm
import model_v4 stop
generate p p > t1 t1~, (t1 > t n1, t > w+ b, w+ > e+ ve), (t1~ > t~ n1, t~ > w- b~, w- > e- ve~)
output ststbdilepton
</MG5ProcCard>
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# proc_card.dat *
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# WARNING: This Files is generated for MADEVENT (compatibility issue)*
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# Running this in MG4 will NEVER reproduce the result of MG5*
# *
#*********************************************************************
#*********************************************************************
# Process(es) requested : mg2 input *
#*********************************************************************
# Begin PROCESS # This is TAG. Do not modify this line
p p > t1 t1~ , (t1 > t n1 , t > w+ b , w+ > e+ ve) , (t1~ > t~ n1 , t~ > w- b~ , w- > e- ve~) #Process
# Be carefull the coupling are here in MG5 convention
end_coup # End the couplings input
done # this tells MG there are no more procs
# End PROCESS # This is TAG. Do not modify this line
#*********************************************************************
# Model information *
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# Begin MODEL # This is TAG. Do not modify this line
stop
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#*********************************************************************
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# 0. REFRAIN from editing this file by hand! Some of the parame- *
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     3 1.18000000E-01 # alpha_s(MZ) SM MSbar
     4 9.15445065E+01 # Z mass (as input parameter)
Block MGYUKAWA # Yukawa masses m/v=y/sqrt(2)
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     5 4.20000000E+00 # mbottom for the Yukawa y_b
     4 1.25000000E+00 # mcharm for the Yukawa y_c
     6 1.74300000E+02 # mtop for the Yukawa y_t
    15 1.77700000E+00 # mtau for the Yukawa y_ta
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#===========================================================
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         5 4.20000000E+00 # bottom pole mass
         6 1.73500000E+02 # top pole mass
        15 1.77700000E+00 # tau mass
        23 9.15445065E+01 # Z mass
        24 8.02673592E+01 # W mass
        25 1.20000000E+02 # H mass
   1000006 4.00000000e+02 # MT1
   1000022 2.00000000e+02 # MN1
# PDG Width
DECAY 1000006 4.87257483e-01 # t1 decays
# BR NDA ID1 ID2
     1.00000000e+00 2 1000022 6 # BR(t1 -> n1 t )
#
DECAY -1000006 4.87792385e-01 # t1~ decays
# BR NDA ID1 ID2
     1.00000000e+00 2 -6 1000022 # BR(t1~ -> t~ n1 )
#
DECAY 6 1.50530838e+00 # t decays
# BR NDA ID1 ID2
     1.00000000e+00 2 5 24 # BR(t -> b w+ )
#
DECAY -6 1.50213703e+00 # t~ decays
# BR NDA ID1 ID2
     1.00000000e+00 2 -5 -24 # BR(t~ -> b~ w- )
#
DECAY 24 2.03211963e+00 # w+ decays
# BR NDA ID1 ID2
     3.31965773e-01 2 2 -1 # BR(w+ -> u d~ )
     3.34295852e-01 2 4 -3 # BR(w+ -> c s~ )
     1.11419809e-01 2 12 -11 # BR(w+ -> ve e+ )
     1.10905350e-01 2 14 -13 # BR(w+ -> vm mu+ )
     1.11413216e-01 2 16 -15 # BR(w+ -> vt ta+ )
#
DECAY -24 2.04265247e+00 # w- decays
# BR NDA ID1 ID2
     3.34080231e-01 2 1 -2 # BR(w- -> d u~ )
     3.34794486e-01 2 3 -4 # BR(w- -> s c~ )
     1.09609664e-01 2 11 -12 # BR(w- -> e- ve~ )
     1.10449835e-01 2 13 -14 # BR(w- -> mu- vm~ )
     1.11065784e-01 2 15 -16 # BR(w- -> ta- vt~ )
#
DECAY 1000022 1.00000000e+00 # WN1
DECAY 23 2.44639985E+00 # Z width
DECAY 25 6.79485838E-03 # H width
BLOCK MGUSER
         1 0.00000000e+00 # a_cp ,first variable name
         2 0.00000000e+00 # b_cp ,second variable name
         3 0.00000000e+00 # c_cp ,second variable name
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#*********************************************************************
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  .false. = gridpack !True = setting up the grid pack
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# Number of events and rnd seed *
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  20000 = nevents ! Number of unweighted events requested
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 'cteq6l1' = pdlabel ! PDF set
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# Renormalization and factorization scales *
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 F = fixed_ren_scale ! if .true. use fixed ren scale
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# Matching - Warning! ickkw > 1 is still beta
#*********************************************************************
 0 = ickkw ! 0 no matching, 1 MLM, 2 CKKW matching
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#*********************************************************************
# Automatic ptj and mjj cuts if xqcut > 0
# (turn off for VBF and single top processes)
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   T = auto_ptj_mjj ! Automatic setting of ptj and mjj
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#
#**********************************
# BW cutoff (M+/-bwcutoff*Gamma)
#**********************************
  15 = bwcutoff ! (M+/-bwcutoff*Gamma)
#**********************************************************
# Apply pt/E/eta/dr/mij cuts on decay products or not
# (note that etmiss/ptll/ptheavy/ht/sorted cuts always apply)
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   T = cut_decays ! Cut decay products
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# long decay chains e.g.).
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#*******************
#
#*********************************************************************
# Minimum and maximum pt's *
#*********************************************************************
  0 = ptj ! minimum pt for the jets
  0 = ptb ! minimum pt for the b
  0 = pta ! minimum pt for the photons
  0 = ptl ! minimum pt for the charged leptons
  0 = misset ! minimum missing Et (sum of neutrino's momenta)
  0 = ptheavy ! minimum pt for one heavy final state
 1.0 = ptonium ! minimum pt for the quarkonium states
 1d5 = ptjmax ! maximum pt for the jets
 1d5 = ptbmax ! maximum pt for the b
 1d5 = ptamax ! maximum pt for the photons
 1d5 = ptlmax ! maximum pt for the charged leptons
 1d5 = missetmax ! maximum missing Et (sum of neutrino's momenta)
#*********************************************************************
# Minimum and maximum E's (in the lab frame) *
#*********************************************************************
  0 = ej ! minimum E for the jets
  0 = eb ! minimum E for the b
  0 = ea ! minimum E for the photons
  0 = el ! minimum E for the charged leptons
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 1d5 = ebmax ! maximum E for the b
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 1d5 = elmax ! maximum E for the charged leptons
#*********************************************************************
# Maximum and minimum rapidity *
#*********************************************************************
 1d2 = etaj ! max rap for the jets
 1d2 = etab ! max rap for the b
 1d2 = etaa ! max rap for the photons
 1d2 = etal ! max rap for the charged leptons
 1d2 = etaonium ! max rap for the quarkonium states
 0d0 = etajmin ! min rap for the jets
 0d0 = etabmin ! min rap for the b
 0d0 = etaamin ! min rap for the photons
 0d0 = etalmin ! main rap for the charged leptons
#*********************************************************************
# Minimum and maximum DeltaR distance *
#*********************************************************************
 0 = drjj ! min distance between jets
 0 = drbb ! min distance between b's
 0 = drll ! min distance between leptons
 0 = draa ! min distance between gammas
 0 = drbj ! min distance between b and jet
 0 = draj ! min distance between gamma and jet
 0 = drjl ! min distance between jet and lepton
 0 = drab ! min distance between gamma and b
 0 = drbl ! min distance between b and lepton
 0 = dral ! min distance between gamma and lepton
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 1d2 = drbbmax ! max distance between b's
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 1d2 = drabmax ! max distance between gamma and b
 1d2 = drblmax ! max distance between b and lepton
 1d2 = dralmax ! maxdistance between gamma and lepton
#*********************************************************************
# Minimum and maximum invariant mass for pairs *
#*********************************************************************
 0 = mmjj ! min invariant mass of a jet pair
 0 = mmbb ! min invariant mass of a b pair
 0 = mmaa ! min invariant mass of gamma gamma pair
 0 = mmll ! min invariant mass of l+l- (same flavour) lepton pair
 1d5 = mmjjmax ! max invariant mass of a jet pair
 1d5 = mmbbmax ! max invariant mass of a b pair
 1d5 = mmaamax ! max invariant mass of gamma gamma pair
 1d5 = mmllmax ! max invariant mass of l+l- (same flavour) lepton pair
#*********************************************************************
# Minimum and maximum invariant mass for all letpons *
#*********************************************************************
 0 = mmnl ! min invariant mass for all letpons (l+- and vl)
 1d5 = mmnlmax ! max invariant mass for all letpons (l+- and vl)
#*********************************************************************
# Minimum and maximum pt for 4-momenta sum of leptons *
#*********************************************************************
 0 = ptllmin ! Minimum pt for 4-momenta sum of leptons(l and vl)
 1d5 = ptllmax ! Maximum pt for 4-momenta sum of leptons(l and vl)
#*********************************************************************
# Inclusive cuts *
#*********************************************************************
 0 = xptj ! minimum pt for at least one jet
 0 = xptb ! minimum pt for at least one b
 0 = xpta ! minimum pt for at least one photon
 0 = xptl ! minimum pt for at least one charged lepton
#*********************************************************************
# Control the pt's of the jets sorted by pt *
#*********************************************************************
 0 = ptj1min ! minimum pt for the leading jet in pt
 0 = ptj2min ! minimum pt for the second jet in pt
 0 = ptj3min ! minimum pt for the third jet in pt
 0 = ptj4min ! minimum pt for the fourth jet in pt
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 1d5 = ptj2max ! maximum pt for the second jet in pt
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 1d5 = ptj4max ! maximum pt for the fourth jet in pt
 0 = cutuse ! reject event if fails any (0) / all (1) jet pt cuts
#*********************************************************************
# Control the pt's of leptons sorted by pt *
#*********************************************************************
 0 = ptl1min ! minimum pt for the leading lepton in pt
 0 = ptl2min ! minimum pt for the second lepton in pt
 0 = ptl3min ! minimum pt for the third lepton in pt
 0 = ptl4min ! minimum pt for the fourth lepton in pt
 1d5 = ptl1max ! maximum pt for the leading lepton in pt
 1d5 = ptl2max ! maximum pt for the second lepton in pt
 1d5 = ptl3max ! maximum pt for the third lepton in pt
 1d5 = ptl4max ! maximum pt for the fourth lepton in pt
#*********************************************************************
# Control the Ht(k)=Sum of k leading jets *
#*********************************************************************
 0 = htjmin ! minimum jet HT=Sum(jet pt)
 1d5 = htjmax ! maximum jet HT=Sum(jet pt)
 0 = ihtmin !inclusive Ht for all partons (including b)
 1d5 = ihtmax !inclusive Ht for all partons (including b)
 0 = ht2min ! minimum Ht for the two leading jets
 0 = ht3min ! minimum Ht for the three leading jets
 0 = ht4min ! minimum Ht for the four leading jets
 1d5 = ht2max ! maximum Ht for the two leading jets
 1d5 = ht3max ! maximum Ht for the three leading jets
 1d5 = ht4max ! maximum Ht for the four leading jets
#*********************************************************************
# WBF cuts *
#*********************************************************************
 0 = xetamin ! minimum rapidity for two jets in the WBF case
 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) *
#*********************************************************************
 4 = maxjetflavor ! Maximum jet pdg code
#*********************************************************************
# Jet measure cuts *
#*********************************************************************
 0 = xqcut ! minimum kt jet measure between partons
#*********************************************************************
</MGRunCard>
<MGGenerationInfo>
# Number of Events : 20000
# Integrated weight (pb) : .38415E+00
# Truncated wgt (pb) : .00000E+00
# Unit wgt : .19207E-04
</MGGenerationInfo>

Question information

Language:
English Edit question
Status:
Solved
For:
MadGraph5_aMC@NLO Edit question
Assignee:
No assignee Edit question
Solved by:
Johan Alwall
Solved:
Last query:
Last reply:
Revision history for this message
Best Johan Alwall (johan-alwall) said :
#1

Hello Rakhi,

You are missing a parenthesis:
p p > t1 t1~, (t1 > t n1, (t > w+ b, w+ > e+ ve)), (t1~ > t~ n1, (t~ > w- b~, w- > e- ve~))

All the best,
Johan

Revision history for this message
Rakhi Mahbubani (r-mahbubani) said :
#2

Oops! thanks :)

Revision history for this message
Rakhi Mahbubani (r-mahbubani) said :
#3

Thanks Johan Alwall, that solved my question.