## \file ## \ingroup tutorial_roofit ## \notebook -nodraw ## ## Organization and simultaneous fits: illustration use of ROOT.RooCustomizer and ## ROOT.RooSimWSTool interface in factory workspace tool in a complex standalone B physics example ## ## \macro_code ## ## \date February 2018 ## \authors Clemens Lange, Wouter Verkerke (C++ version) import ROOT w = ROOT.RooWorkspace("w") # Build a complex example pdf # ----------------------------------------------------------- # Make signal model for CPV: A bmixing decay function in t (convoluted with a triple Gaussian resolution model) # times a Gaussian function the reconstructed mass w.factory( "PROD::sig( BMixDecay::sig_t( dt[-20,20], mixState[mixed=1,unmix=-1], tagFlav[B0=1,B0bar=-1], " "tau[1.54], dm[0.472], w[0.05], dw[0], " "AddModel::gm({GaussModel(dt,biasC[-10,10],sigmaC[0.1,3],dterr[0.01,0.2]), " "GaussModel(dt,0,sigmaT[3,10]), " "GaussModel(dt,0,20)},{fracC[0,1],fracT[0,1]}), " "DoubleSided ), " "Gaussian::sig_m( mes[5.20,5.30], mB0[5.20,5.30], sigmB0[0.01,0.05] ))") # Make background component: A plain decay function in t times an Argus # function in the reconstructed mass w.factory("PROD::bkg( Decay::bkg_t( dt, tau, gm, DoubleSided), " "ArgusBG::bkg_m( mes, 5.291, k[-100,-10]))") # Make composite model from the signal and background component w.factory("SUM::model( Nsig[5000,0,10000]*sig, NBkg[500,0,10000]*bkg )") # Example of RooSimWSTool interface # ------------------------------------------------------------------ # Introduce a flavour tagging category tagCat as observable with 4 states corresponding # to 4 flavour tagging techniques with different performance that require different # parameterizations of the fit model # # ROOT.RooSimWSTool operation: # - Make 4 clones of model (for each tagCat) state, will gain an individual # copy of parameters w, and biasC. The other parameters remain common # - Make a simultaneous p.d.f. of the 4 clones assigning each to the appropriate # state of the tagCat index category # ROOT.RooSimWSTool is interfaced as meta-type SIMCLONE in the factory. The $SplitParam() # argument maps to the SplitParam() named argument in the # ROOT.RooSimWSTool constructor w.factory( "SIMCLONE::model_sim( model, $SplitParam({w,dw,biasC},tagCat[Lep,Kao,NT1,NT2]))") # Example of RooCustomizer interface # ------------------------------------------------------------------- # # Class ROOT.RooCustomizer makes clones of existing p.d.f.s with certain prescribed # modifications (branch of leaf node replacements) # # Here we take our model (the original before ROOT.RooSimWSTool modifications) # and request that the parameter w (the mistag rate) is replaced with # an expression-based function that calculates w in terms of the Dilution # parameter D that is defined D = 1-2*w # Make a clone model_D of original 'model' replacing 'w' with # 'expr('0.5-D/2',D[0,1])' w.factory("EDIT::model_D(model, w=expr('0.5-D/2',D[0,1]) )") # Print workspace contents w.Print() # Make workspace visible on command line ROOT.gDirectory.Add(w)