# Sherpa2.1.1(+OpenLoops1.2.2) runcard for HXSWG studies of ttbb 
# NLO pp->ttbb at 13TeV in the 4F scheme
# last changed by Niccolo Moretti, 23.09.15 

(run){
  
  ### Output redirection and format

  ANALYSIS_OUTPUT = Analyses21/ttbjets_NLO1_partv1/ttbjets_RNseed 
  LOG_FILE Logs21/ttbjets_NLO1_partv1/ttbjets_RNseed.txt 
  OUTPUT=2
  PRETTY_PRINT = Off
  RESULT_DIRECTORY = Results21/ttbjets_NLO1

  #EVENT_OUTPUT=HepMC_GenEvent[S_RNseed]      # uncomment this in order to store event samples
  ANALYSIS = Rivet

  ### Generator and integration parameters
    
  ME_SIGNAL_GENERATOR Comix LOOPGEN  
  EVENT_GENERATION_MODE=Weighted
  EVENTS=100000                     # this # of events requires 5 CPU hours/core and yields mid-low statistics with 100 cores 
#  EVENTS=400000                    # this yields mid statistics with 100 cores 
                                                    
                                                       

  RANDOM_SEED=RNseed                # relevant only for event generation
  EVENT_SEED_MODE 3                 # guarantees reproducible random number assignements for MEs, decays, shower

  ### NLO parameters
  
  LOOPGEN:=OpenLoops
  OL_GENERATE_LIST=1  
  DIPOLE_ALPHA 0.3


  ### Beams for 13TeV LHC

  BEAM_1=2212; BEAM_ENERGY_1=6500
  BEAM_2=2212; BEAM_ENERGY_2=6500

  ### PDFs
 
  PDF_LIBRARY LHAPDFSherpa
  PDF_SET NNPDF30_nlo_as_0118_nf_4   # standard NNPDF30nlo 4F NLO pdfs
  USE_PDF_ALPHAS=1                   # takes alphaS from LHApdfs (for MEs and shower)
  
 
  ### Switch off non-perturbative contributions

  DECAYMODEL=Off
  FRAGMENTATION=Off
  BEAM_REMNANTS=0
  MI_HANDLER = None
  YFS_MODE=0
  ME_QED=Off
  SHOWER_GENERATOR = None

  ### top and bottom masses in MEs and PS

  MASS[6]=172.5 
  WIDTH[6]=0                   # zero width for stable tops and after-burner on-shell top decays

  MASS[5] = 4.75	       # b-mass parameter (4.75 or 0)
  MASSIVE[5]=1                 # b-mass switcher for MEs: massive (1) or massless (0)
                               # NB: partons with MASSIVE=1 excluded from proton/light-jet container (93)
       
 
  ### Scale settings: mu_F=HT/2 and mu_R= ET geometric mean

  SCALES VAR{0.25*H_TM2}{sqrt(MPerp(p[2])*MPerp(p[3])*MPerp(p[4])*MPerp(p[5]))}

 }(run)


(processes){
  Process 93 93 -> 6 -6 5 -5    # pp -> t t b b 
  Order_EW 0		        # pure QCD contributions 
  NLO_QCD_Mode Fixed_Order
  Loop_Generator LOOPGEN
  RS_PSI_ItMin 350000           # minimum number of events per optimisation step for RS part(default is 5000) 
  
  End process
}(processes)

(selector){
}(selector)


(analysis){
BEGIN_RIVET { 
	USE_HEPMC_SHORT 1
	-a  hxswg_ttbjets_part_v1
    } END_RIVET
}(analysis)