No event production with NLO EWK process

Asked by Liqing Zhang on 2018-10-14

Dear aMC@NLO experts,

I was producing www process with the folloing commands:
   set complex_mass_scheme True
   import model loop_qcd_qed_sm_Gmu
   generate p p > w+ w- w+ [QED]
The PDF I used is LHAPDF with number 82000.

I have two questions about this process.
1>After 'launch', there is no event production
2>When I increased the number of events, the erroe of cross section didn't improve. I list the cross section with different events requested.
  10000 events : 8.259e-02 +- 7.1e-04 pb
  100000 events : 8.250e-02 +- 4.2e-04 pb
  1000000 events : 8.290e-02 +- 4.4e-04 pb

I would appreciate all suggestions you may have. Thank you in advance.

Best,
Liqing

Question information

Language:
English Edit question
Status:
Open
For:
MadGraph5_aMC@NLO Edit question
Assignee:
davide.pagani.85 Edit question
Last query:
2018-10-18
Last reply:
2018-10-17

Hi Liqing,

at the moment with the version 3.0.0 is not possible to generate events including EW corrections, this is why you have to use fixed order and you do not generate events.

If you want to increase the accuracy, please use the parameter

req_acc_FO

Cheers
Davide

Liqing Zhang (liqing.zhang) said : #2

Hi Davide,

Thanks a lot for you reply.

I have two futher questions:
1>I was bouble calculating the cross section in the paper, arXiv:1804.10017, to make sure my setting are correct. I modified the run_card.dat and para_card.dat to be same with paper, but the cross section I got is a little bit different with paper. I attched those file, could you please help to check where is still different?
with 10^4 event, LO cross section is 0.08225 +- 5.399e-05 pb
with 10^5 event LO cross section is 0.08242 +- 1.85e-05 pb

2>I work on WWW analysis that decay to lvlvjj, I need to calculate the NLO EW correction in fiducial region. It means I need to generate NLO EW process with W decay. As far as I know, MadSpin can handle the W decay basing on a lhe file. But you mentioned that version 3.0.0 is not possible to generate events including EW corrections. In this case, do you know how can I calculate the EW correction in the fiducial region?

Best,
Liqing
________________________________________
From: <email address hidden> [<email address hidden>] on behalf of davide.pagani.85 [<email address hidden>]
Sent: Monday, October 15, 2018 15:32
To: Liqing Zhang
Subject: Re: [Question #675174]: No event production with NLO EWK process

Your question #675174 on MadGraph5_aMC@NLO changed:
https://answers.launchpad.net/mg5amcnlo/+question/675174

    Status: Open => Answered

davide.pagani.85 proposed the following answer:
Hi Liqing,

at the moment with the version 3.0.0 is not possible to generate events
including EW corrections, this is why you have to use fixed order and
you do not generate events.

If you want to increase the accuracy, please use the parameter

req_acc_FO

Cheers
Davide

--
If this answers your question, please go to the following page to let us
know that it is solved:
https://answers.launchpad.net/mg5amcnlo/+question/675174/+confirm?answer_id=0

If you still need help, you can reply to this email or go to the
following page to enter your feedback:
https://answers.launchpad.net/mg5amcnlo/+question/675174

You received this question notification because you asked the question.

1: can you please attach your param_card.dat and run_card.dat?

2: The full lvlvjj process is certainly time consuming. At the moment since events cannot be generated, the MadSpin option is not possible. Let me say anyway that even having MadSpin, this would not be so helpful because the EW corrections would be only in the production and not in the decay, and photon emission from the leptons may be very relevant. In this way you would just consider the EW corrections for the production but not the decay, within signal region.

I think the best you can do at the moment is computing it for WWW production only, trying to impose effective cuts on the Ws that can better simulatethe effects for your cuts for the fiducial region.
Also, if you have any veto for extra jets, you can impose it in Subprocess/cuts.f.

As I said you can also give a try for lvlvjj, but being 2->6 it would take long.

I hope this can helps you.

Liqing Zhang (liqing.zhang) said : #4

Hi Davide,

Thanks a lot for your reply.

For the question <1>, the LO corss section I showed in previous email is got using 'generate p p > w+ w- w+'. After I using 'generate p p > w+ w- w+ [QED]' the cross section is similar with paper. I'm not sure it is the reason or not. I attached the param_card.dat, run_card.dat and proc_card_mg5.dat files for the case of 'generate p p > w+ w- w+'

Best,
Liqing

=================proc_card_mg5.dat
set default_unset_couplings 99
set group_subprocesses Auto
set ignore_six_quark_processes False
set loop_optimized_output True
set include_lepton_initiated_processes False
set loop_color_flows False
set gauge unitary
set max_npoint_for_channel 0
set complex_mass_scheme True
import model loop_qcd_qed_sm_Gmu
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~
define p = 21 2 4 1 3 -2 -4 -1 -3 5 -5 22 # pass to 5 flavors
define j = p
define p = g d d~ u u~ s s~ c c~ b b~ a
define j = g d d~ u u~ s s~ c c~ b b~ a
generate p p > w+ w- w+
output WWW_EK

=================pare_card.dat
###################################
## INFORMATION FOR LOOP
###################################
Block loop
  666 1.000000e+03 # MU_R

###################################
## INFORMATION FOR MASS
###################################
Block mass
    6 1.733400e+02 # MT
   23 9.118760e+01 # MZ
   24 8.038500e+01 # MW
   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 0.000000 # d : 0.0
  2 0.000000 # u : 0.0
  3 0.000000 # s : 0.0
  4 0.000000 # c : 0.0
  5 0.000000 # b : 0.0
  11 0.000000 # e- : 0.0
  12 0.000000 # ve : 0.0
  13 0.000000 # mu- : 0.0
  14 0.000000 # vm : 0.0
  15 0.000000 # ta- : 0.0
  16 0.000000 # vt : 0.0
  21 0.000000 # g : 0.0
  22 0.000000 # a : 0.0
  9000002 91.188000 # ghz : MZ
  9000003 80.419000 # ghwp : MW
  9000004 80.419000 # ghwm : MW
  250 91.188000 # g0 : MZ
  251 80.419000 # g+ : MW

###################################
## INFORMATION FOR SMINPUTS
###################################
Block sminputs
    2 1.166390e-05 # Gf
    3 1.180000e-01 # aS

###################################
## INFORMATION FOR DECAY
###################################
DECAY 6 1.369180e+00 # WT
DECAY 23 2.49550e+00 # WZ
DECAY 24 2.08970e+00 # WW
DECAY 25 4.070e-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 0.000000 # d : 0.0
DECAY 2 0.000000 # u : 0.0
DECAY 3 0.000000 # s : 0.0
DECAY 4 0.000000 # c : 0.0
DECAY 5 0.000000 # b : 0.0
DECAY 11 0.000000 # e- : 0.0
DECAY 12 0.000000 # ve : 0.0
DECAY 13 0.000000 # mu- : 0.0
DECAY 14 0.000000 # vm : 0.0
DECAY 15 0.000000 # ta- : 0.0
DECAY 16 0.000000 # vt : 0.0
DECAY 21 0.000000 # g : 0.0
DECAY 22 0.000000 # a : 0.0
DECAY 250 2.498770 # g0 : WZ
DECAY 251 2.092910 # g+ : WW
#===========================================================
# QUANTUM NUMBERS OF NEW STATE(S) (NON SM PDG CODE)
#===========================================================

Block QNUMBERS 250 # g0
        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 0 # Particle/Antiparticle distinction (0=own anti)
Block QNUMBERS 251 # g+
        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)

==============================run_card.dat
#*********************************************************************
# 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 *
# If you want to run Pythia, avoid more than 50k events in a run. *
#*********************************************************************
  1000000 = 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 *
#*********************************************************************
     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
     82000 = lhaid ! if pdlabel=lhapdf, this is the lhapdf number
# To see heavy ion options: type "update ion_pdf"
#*********************************************************************
# Renormalization and factorization scales *
#*********************************************************************
False = fixed_ren_scale ! if .true. use fixed ren scale
 False = fixed_fac_scale ! if .true. use fixed fac scale
 91.188 = scale ! fixed ren scale
 91.188 = dsqrt_q2fact1 ! fixed fact scale for pdf1
 91.188 = dsqrt_q2fact2 ! fixed fact scale for pdf2
 3 = 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)
  3.0 = lhe_version ! Change the way clustering information pass to shower.
  True = clusinfo ! include clustering tag in output
  average = event_norm ! average/sum. Normalization of the weight in the LHEF

#*********************************************************************
# Matching parameter (MLM only)
#*********************************************************************
 0 = ickkw ! 0 no matching, 1 MLM
 1.0 = alpsfact ! scale factor for QCD emission vx
 False = chcluster ! cluster only according to channel diag
 4 = asrwgtflavor ! highest quark flavor for a_s reweight
 False = auto_ptj_mjj ! Automatic setting of ptj and mjj if xqcut >0
                                   ! (turn off for VBF and single top processes)
 0.0 = xqcut ! minimum kt jet measure between partons
#*********************************************************************
#
#*********************************************************************
# handling of the helicities:
# 0: sum over all helicities
# 1: importance sampling over helicities
#*********************************************************************
   0 = nhel ! using helicities importance sampling or not.
#*********************************************************************
# 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)
#*********************************************************************
# Apply pt/E/eta/dr/mij/kt_durham cuts on decay products or not
# (note that etmiss/ptll/ptheavy/ht/sorted cuts always apply)
#*********************************************************************
   False = cut_decays ! Cut decay products
#*********************************************************************
# Standard Cuts *
#*********************************************************************
# Minimum and maximum pt's (for max, -1 means no cut) *
#*********************************************************************
 20.0 = ptj ! minimum pt for the jets
 0.0 = ptb ! minimum pt for the b
 10.0 = pta ! minimum pt for the photons
 10.0 = ptl ! minimum pt for the charged leptons
 0.0 = misset ! minimum missing Et (sum of neutrino's momenta)
 -1.0 = ptjmax ! maximum pt for the jets
 -1.0 = ptbmax ! maximum pt for the b
 -1.0 = ptamax ! maximum pt for the photons
 -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})
#*********************************************************************
# Minimum and maximum E's (in the center of mass frame) *
#*********************************************************************
  0.0 = ej ! minimum E for the jets
  0.0 = eb ! minimum E for the b
  0.0 = ea ! minimum E for the photons
  0.0 = el ! minimum E for the charged leptons
  -1.0 = ejmax ! maximum E for the jets
 -1.0 = ebmax ! maximum E for the b
 -1.0 = eamax ! maximum E for the photons
 -1.0 = elmax ! maximum E for the charged leptons
 {} = e_min_pdg ! E cut for other particles (use pdg code). Applied on particle and anti-particle
 {} = e_max_pdg ! E cut for other particles (syntax e.g. {6: 100, 25: 50})
#*********************************************************************
# Maximum and minimum absolute rapidity (for max, -1 means no cut) *
#*********************************************************************
  5.0 = etaj ! max rap for the jets
  -1.0 = etab ! max rap for the b
 2.5 = etaa ! max rap for the photons
 2.5 = etal ! max rap for the charged leptons
 0.0 = etajmin ! min rap for the jets
 0.0 = etabmin ! min rap for the b
 0.0 = etaamin ! min rap for the photons
 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
 0.0 = drbb ! min distance between b's
 0.4 = drll ! min distance between leptons
 0.4 = draa ! min distance between gammas
 0.0 = drbj ! min distance between b and jet
 0.4 = draj ! min distance between gamma and jet
 0.4 = drjl ! min distance between jet and lepton
 0.0 = drab ! min distance between gamma and b
 0.0 = drbl ! min distance between b and lepton
 0.4 = dral ! min distance between gamma and lepton
 -1.0 = drjjmax ! max distance between jets
 -1.0 = drbbmax ! max distance between b's
 -1.0 = drllmax ! max distance between leptons
 -1.0 = draamax ! max distance between gammas
 -1.0 = drbjmax ! max distance between b and jet
 -1.0 = drajmax ! max distance between gamma and jet
 -1.0 = drjlmax ! max distance between jet and lepton
 -1.0 = drabmax ! max distance between gamma and b
 -1.0 = drblmax ! max distance between b and lepton
 -1.0 = dralmax ! maxdistance between gamma and lepton
#*********************************************************************
# Minimum and maximum invariant mass for pairs *
# WARNING: for four lepton final state mmll cut require to have *
# different lepton masses for each flavor! *
#*********************************************************************
 0.0 = mmjj ! min invariant mass of a jet pair
 0.0 = mmbb ! min invariant mass of a b pair
 0.0 = mmaa ! min invariant mass of gamma gamma pair
 0.0 = mmll ! min invariant mass of l+l- (same flavour) lepton pair
 -1.0 = mmjjmax ! max invariant mass of a jet pair
 -1.0 = mmbbmax ! max invariant mass of a b pair
 -1.0 = mmaamax ! max invariant mass of gamma gamma pair
 -1.0 = mmllmax ! max invariant mass of l+l- (same flavour) lepton 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 *
#*********************************************************************
 0.0 = ptllmin ! Minimum pt for 4-momenta sum of leptons(l and vl)
 -1.0 = ptllmax ! Maximum pt for 4-momenta sum of leptons(l and vl)
#*********************************************************************
# Inclusive cuts *
#*********************************************************************
 0.0 = ptheavy ! minimum pt for at least one heavy final state
 0.0 = xptj ! minimum pt for at least one jet
 0.0 = xptb ! minimum pt for at least one b
 0.0 = xpta ! minimum pt for at least one photon
 0.0 = xptl ! minimum pt for at least one charged lepton
#*********************************************************************
# Control the pt's of the jets sorted by pt *
#*********************************************************************
 0.0 = ptj1min ! minimum pt for the leading jet in pt
 0.0 = ptj2min ! minimum pt for the second jet in pt
 0.0 = ptj3min ! minimum pt for the third jet in pt
 0.0 = ptj4min ! minimum pt for the fourth 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
 -1.0 = ptj3max ! maximum pt for the third jet in pt
 -1.0 = 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 *
#*********************************************************************
 0.0 = ptl1min ! minimum pt for the leading lepton in pt
 0.0 = ptl2min ! minimum pt for the second lepton in pt
 0.0 = ptl3min ! minimum pt for the third lepton in pt
 0.0 = ptl4min ! minimum pt for the fourth lepton in pt
 -1.0 = ptl1max ! maximum pt for the leading lepton in pt
 -1.0 = ptl2max ! maximum pt for the second lepton in pt
 -1.0 = ptl3max ! maximum pt for the third lepton in pt
 -1.0 = ptl4max ! maximum pt for the fourth lepton in pt
#*********************************************************************
# 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)
 0.0 = ht2min ! minimum Ht for the two leading jets
 0.0 = ht3min ! minimum Ht for the three leading jets
 0.0 = ht4min ! minimum Ht for the four leading jets
 -1.0 = ht2max ! maximum Ht for the two leading jets
 -1.0 = ht3max ! maximum Ht for the three leading jets
 -1.0 = ht4max ! maximum Ht for the four leading jets
#***********************************************************************
# Photon-isolation cuts, according to hep-ph/9801442 *
# When ptgmin=0, all the other parameters are ignored *
# When ptgmin>0, pta and draj are not going to be used *
#***********************************************************************
 0.0 = ptgmin ! Min photon transverse momentum
 0.4 = R0gamma ! Radius of isolation code
1.0 = xn ! n parameter of eq.(3.4) in hep-ph/9801442
 1.0 = epsgamma ! epsilon_gamma parameter of eq.(3.4) in hep-ph/9801442
 True = isoEM ! isolate photons from EM energy (photons and leptons)
#*********************************************************************
# WBF cuts *
#*********************************************************************
 0.0 = xetamin ! minimum rapidity for two jets in the WBF case
 0.0 = deltaeta ! minimum rapidity for two jets in the WBF case
#***********************************************************************
# Turn on either the ktdurham or ptlund cut to activate *
# CKKW(L) merging with Pythia8 [arXiv:1410.3012, arXiv:1109.4829] *
#***********************************************************************
 -1.0 = ktdurham
 0.4 = dparameter
 -1.0 = ptlund
 1, 2, 3, 4, 5, 6, 21, 9000005 = pdgs_for_merging_cut ! PDGs for two cuts above
#*********************************************************************
# maximal pdg code for quark to be considered as a light jet *
# (otherwise b cuts are applied) *
#*********************************************************************
 4 = maxjetflavor ! Maximum jet pdg code
#*********************************************************************
#
#*********************************************************************
# Store info for systematics studies *
# WARNING: Do not use for interference type of computation *
#*********************************************************************
   True = use_syst ! Enable systematics studies
#
systematics = 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

________________________________________
From: <email address hidden> [<email address hidden>] on behalf of davide.pagani.85 [<email address hidden>]
Sent: Wednesday, October 17, 2018 21:52
To: Liqing Zhang
Subject: Re: [Question #675174]: No event production with NLO EWK process

Your question #675174 on MadGraph5_aMC@NLO changed:
https://answers.launchpad.net/mg5amcnlo/+question/675174

    Status: Open => Needs information

davide.pagani.85 requested more information:
1: can you please attach your param_card.dat and run_card.dat?

2: The full lvlvjj process is certainly time consuming. At the moment
since events cannot be generated, the MadSpin option is not possible.
Let me say anyway that even having MadSpin, this would not be so helpful
because the EW corrections would be only in the production and not in
the decay, and photon emission from the leptons may be very relevant. In
this way you would just consider the EW corrections for the production
but not the decay, within signal region.

I think the best you can do at the moment is computing it for WWW production only, trying to impose effective cuts on the Ws that can better simulatethe effects for your cuts for the fiducial region.
Also, if you have any veto for extra jets, you can impose it in Subprocess/cuts.f.

As I said you can also give a try for lvlvjj, but being 2->6 it would
take long.

I hope this can helps you.

--
To answer this request for more information, you can either reply to
this email or enter your reply at the following page:
https://answers.launchpad.net/mg5amcnlo/+question/675174

You received this question notification because you asked the question.

Can you help with this problem?

Provide an answer of your own, or ask Liqing Zhang for more information if necessary.

To post a message you must log in.