Dear developers, I am having an issue with the pythia MLM merging in Madgraph. I generated 50000 p p > t t~ events. The relevant bit of the runcard is at the end of my message. The issue is that although I explicitly set Main:numberOfEvents = 50000 in the pythia run card, I end up with only 1250 events showered and merged. The resulting hepmc file does contain 50000 events, of which most of them have weight 0 set by pythia. The log file of pythia states: *------- PYTHIA Event and Cross Section Statistics -------------------------------------------------------------* | | | Subprocess Code | Number of events | sigma +- delta | | | Tried Selected Accepted | (estimated) (mb) | | | | | |-----------------------------------------------------------------------------------------------------------------| | | | | | Les Houches User Process(es) 9999 | 1250 1250 1224 | 2.093e-06 0.000e+00 | | ... whereof user classification code 0 | 285 285 282 | | | ... whereof user classification code 1 | 478 478 467 | | | ... whereof user classification code 2 | 487 487 475 | | | | | | | sum | 1250 1250 1224 | 2.093e-06 0.000e+00 | | | *------- End PYTHIA Event and Cross Section Statistics ----------------------------------------------------------* *------- PYTHIA Error and Warning Messages Statistics ----------------------------------------------------------* | | | times message | | | | 1 Error in Pythia::next: hadronLevel failed; try again | | 1 Error in RopeFragPars::init: failed to insert defaults. | | 1 Error in StringFragmentation::fragment: stuck in joining | | 2 Info from SLHAinterface::initSLHA: No MODSEL found, keeping internal SUSY switched off | | 2 Info from SLHAinterface::initSLHA: importing MASS entries | | 3 Warning in Pythia::check: not quite matched particle energy/momentum/mass | | 2 Warning in SLHAinterface::initSLHA: ignoring DECAY tables | | 2 Warning in SLHAinterface::initSLHA: ignoring MASS entries | | 2 Warning in SLHAinterface::initSLHA: ignoring empty DECAY tables | | 8 Warning in StringFragmentation::fragmentToJunction: bad convergence junction rest frame | | 8 Warning in TimeShower::findMEcorr: ME weight above PS one | | 1 Warning in TimeShower::pTnext: negative dipole mass. | | | *------- End PYTHIA Error and Warning Messages Statistics ------------------------------------------------------* Contribution of sample 0 to the inclusive cross section : 2.08993997e-06 +- 5.97858225e-08 Inclusive cross section: 2.08993997e-06 +- 5.97858225e-08 mb I tried to do the same thing with pythia outside of madgraph on the same lhe file with the same runcard for pythia, and then I get: *------- PYTHIA Event and Cross Section Statistics -------------------------------------------------------------* | | | Subprocess Code | Number of events | sigma +- delta | | | Tried Selected Accepted | (estimated) (mb) | | | | | |-----------------------------------------------------------------------------------------------------------------| | | | | | Les Houches User Process(es) 9999 | 50000 50000 10058 | 2.043e-05 1.575e-07 | | ... whereof user classification code 0 | 11542 11542 3239 | | | ... whereof user classification code 1 | 19314 19314 2881 | | | ... whereof user classification code 2 | 19144 19144 3938 | | | | | | | sum | 50000 50000 10058 | 2.043e-05 1.575e-07 | | | *------- End PYTHIA Event and Cross Section Statistics ----------------------------------------------------------* *------- PYTHIA Error and Warning Messages Statistics ----------------------------------------------------------* | | | times message | | | | 1 Abort from Pythia::next: reached end of Les Houches Events File | | 1 Error in BeamRemnants::setKinematics: kinematics construction failed | | 6 Error in Pythia::next: hadronLevel failed; try again | | 57 Error in SpaceShower::pT2nearThreshold: stuck in loop | | 6 Error in StringFragmentation::fragment: stuck in joining | | 1 Info from SLHAinterface::initSLHA: No MODSEL found, keeping internal SUSY switched off | | 1 Info from SLHAinterface::initSLHA: importing MASS entries | | 2 Warning in MultipartonInteractions::pTnext: weight above unity | | 6 Warning in Pythia::check: not quite matched particle energy/momentum/mass | | 1 Warning in SLHAinterface::initSLHA: ignoring DECAY tables | | 1 Warning in SLHAinterface::initSLHA: ignoring MASS entries | | 1 Warning in SLHAinterface::initSLHA: ignoring empty DECAY tables | | 2 Warning in SpaceShower::pT2nextQCD: small daughter PDF | | 4 Warning in SpaceShower::pT2nextQCD: weight above unity | | 45 Warning in StringFragmentation::fragmentToJunction: bad convergence junction rest frame | | 27 Warning in TimeShower::findMEcorr: ME weight above PS one | | 7 Warning in TimeShower::pTnext: negative dipole mass. | | | *------- End PYTHIA Error and Warning Messages Statistics ------------------------------------------------------* Contribution of sample 0 to the inclusive cross section : 4.30045340e-07 +- 4.28803607e-09 Inclusive cross section: 4.30045340e-07 +- 4.28803607e-09 mb Could you help me figure out what is going wrong?

2.6.1 t t~ @0 add process p p > t t~ j @1 add process p p > t t~ j j @2 output ttbar_jets ]]> t t~ @0 #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 * #********************************************************************* # Begin MODEL # This is TAG. Do not modify this line sm # End MODEL # This is TAG. Do not modify this line #********************************************************************* # Start multiparticle definitions * #********************************************************************* # Begin MULTIPARTICLES # This is TAG. Do not modify this line # End MULTIPARTICLES # This is TAG. Do not modify this line ]]> 0 ! (turn off for VBF and single top processes) 15.0 = 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 20.0 = ptb ! minimum pt for the b 20.0 = pta ! minimum pt for the photons 15.0 = 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) * #********************************************************************* 2.8 = etaj ! max rap for the jets 2.5 = etab ! max rap for the b 2.37 = etaa ! max rap for the photons 2.7 = 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 0.4 = drbb ! min distance between b's 0.4 = drll ! min distance between leptons 0.4 = draa ! min distance between gammas 0.4 = drbj ! min distance between b and jet 0.4 = draj ! min distance between gamma and jet 0.2 = drjl ! min distance between jet and lepton 0.4 = drab ! min distance between gamma and b 0.4 = 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 = 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) * #********************************************************************* 5 = 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 # #************************************** # Parameter of the systematics study # will be used by SysCalc (if installed) #************************************** # 0.5 1 2 = sys_scalefact # factorization/renormalization scale factor None = sys_alpsfact # \alpha_s emission scale factors auto = sys_matchscale # variation of merging scale # PDF sets and number of members (0 or none for all members). NNPDF23_lo_as_0130_qed = sys_pdf # list of pdf sets # MSTW2008nlo68cl.LHgrid 1 = sys_pdf # ]]> ###################################################################### ## PARAM_CARD AUTOMATICALY GENERATED BY MG5 FOLLOWING UFO MODEL #### ###################################################################### ## ## ## Width set on Auto will be computed following the information ## ## present in the decay.py files of the model. ## ## See arXiv:1402.1178 for more details. ## ## ## ###################################################################### ################################### ## INFORMATION FOR MASS ################################### Block mass 5 4.700000e+00 # MB 6 1.730000e+02 # MT 15 1.777000e+00 # MTA 23 9.118800e+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 0.000000 # d : 0.0 2 0.000000 # u : 0.0 3 0.000000 # s : 0.0 4 0.000000 # c : 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 16 0.000000 # vt : 0.0 21 0.000000 # g : 0.0 22 0.000000 # a : 0.0 24 80.419002 # w+ : cmath.sqrt(MZ__exp__2/2. + cmath.sqrt(MZ__exp__4/4. - (aEW*cmath.pi*MZ__exp__2)/(Gf*sqrt__2))) ################################### ## INFORMATION FOR SMINPUTS ################################### Block sminputs 1 1.325070e+02 # aEWM1 2 1.166390e-05 # Gf 3 1.180000e-01 # aS ################################### ## INFORMATION FOR YUKAWA ################################### Block yukawa 5 4.700000e+00 # ymb 6 1.730000e+02 # ymt 15 1.777000e+00 # ymtau ################################### ## INFORMATION FOR DECAY ################################### DECAY 6 1.491500e+00 # WT DECAY 23 2.441404e+00 # WZ DECAY 24 2.047600e+00 # WW DECAY 25 6.382339e-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 directory ! /dev/null : to turn off the HEPMC output. ! : to select where the HEPMC file must written. It will ! therefore not be placed in the run_ directory. The ! specified path, if not absolute, will be relative to ! the Event/run_ directory of the process output. ! fifo : to have MG5aMC setup the piping of the PY8 output to ! analysis tools such as MadAnalysis5. ! fifo@ : ! Same as 'fifo', but selecting a custom path to create the ! fifo pipe. (useful to select a mounted drive that supports ! fifo). Note that the fifo file extension *must* be '.hepmc.fifo'. ! ------------------------------------------------------------------- ! HEPMCoutput:file = tag_1_pythia8_events.hepmc ! ! -------------------------------------------------------------------- ! Parameters relevant only when performing MLM merging, which can be ! turned on by setting ickkw to '1' in the run_card and chosing a ! positive value for the parameter xqcut. ! For details, see section 'Jet Matching' on the left-hand menu of ! http://home.thep.lu.se/~torbjorn/pythia81html/Welcome.html ! -------------------------------------------------------------------- ! If equal to -1.0, MadGraph5_aMC@NLO will set it automatically based ! on the parameter 'xqcut' of the run_card.dat JetMatching:qCut = 2.2500000000e+01 ! Use default kt-MLM to match parton level jets to those produced by the ! shower. But the other Shower-kt scheme is available too with this option. JetMatching:doShowerKt = off ! A value of -1 means that it is automatically guessed by MadGraph. ! It is however always safer to explicitly set it. JetMatching:nJetMax = 2 ! ! -------------------------------------------------------------------- ! Parameters relevant only when performing CKKW-L merging, which can ! be turned on by setting the parameter 'ptlund' *or* 'ktdurham' to ! a positive value. ! For details, see section 'CKKW-L Merging' on the left-hand menu of ! http://home.thep.lu.se/~torbjorn/pythia81html/Welcome.html ! -------------------------------------------------------------------- ! Central merging scale values you want to be used. ! If equal to -1.0, then MadGraph5_aMC@NLO will set this automatically ! based on the parameter 'ktdurham' of the run_card.dat ! The following parameter was forced to be commented out by MG5aMC. ! Merging:TMS = -1.0 ! This must be set manually, according to Pythia8 directives. ! An example of possible value is 'pp>LEPTONS,NEUTRINOS' ! Alternatively, from Pythia v8.223 onwards, the value 'guess' can be ! used to instruct Pythia to guess the hard process. The guess would mean ! that all particles apart from light partons will be considered as a part ! of the hard process. This guess is prone to errors if the desired hard ! process is complicated (i.e. contains light partons). The user should ! then be wary of suspicious error messages in the Pythia log file. ! The following parameter was forced to be commented out by MG5aMC. ! Merging:Process = ! A value of -1 means that it is automatically guessed by MadGraph. ! It is however always safer to explicitly set it. ! The following parameter was forced to be commented out by MG5aMC. ! Merging:nJetMax = -1 ! ! For all merging schemes, decide whehter you want the merging scale ! variation computed for only the central weights or all other ! PDF and scale variation weights as well SysCalc:fullCutVariation = off ! ! ========================== ! User customized parameters ! ========================== ! ! By default, Pythia8 generates multi-parton interaction events. This is ! often irrelevant for phenomenology and very slow. You can turn this ! feature off by uncommenting the line below if so desired. !partonlevel:mpi = off ! ! Additional general parameters. ! JetMatching:merge=on JetMatching:scheme=1 ! ! Additional technical parameters set by MG5_aMC. ! ! 1.0 corresponds to HEPMC weight given in [mb]. We choose here the [pb] normalization. HEPMCoutput:scaling=1.0000000000e+09 SysCalc:qCutList=33.750,45.000 ! Value of the merging scale below which one does not even write the HepMC event. SysCalc:qWeed=1.5000000000e+01 ! This parameter is automatically set to True by MG5aMC when doing MLM merging with PY8. Beams:setProductionScalesFromLHEF=on ! Tell Pythia8 that an LHEF input is used. Beams:frameType=4 ! Specify one must read inputs from the MadGraph banner. JetMatching:setMad=off JetMatching:nQmatch=5 JetMatching:etaJetMax=1.0000000000e+03 JetMatching:coneRadius=1.0000000000e+00 ! Do veto externally (e.g. in SysCalc). JetMatching:doVeto=off ! Be more forgiving with momentum mismatches. Check:epTolErr=1.0000000000e-02 ! ! ==================== ! Subrun definitions ! ==================== ! LHEFInputs:nSubruns=1 Main:subrun=0 ! ! Definition of subrun 0 ! Beams:LHEF=unweighted_events.lhe.gz ]]> ............... continues with delphes information

When	Who	Action	New State
2018-04-28	Launchpad Janitor	Expire	Expired
2018-04-28	Olivier Mattelaer	Comment	Expired

MadGraph5_aMC@NLO

History of question #667844