python/physicsutils/VBF.py

0001 import math
0002 from ROOT import TLorentzVector
0003 from PhysicsTools.HeppyCore.utils.deltar import deltaPhi, deltaR2
0004
0005 class VBF( object ):
0006     '''Computes and holds VBF quantities'''
0007     def __init__(self, jets, diLepton, vbfMvaCalc, cjvPtCut):
0008         '''jets: jets cleaned from the diLepton legs.
0009         diLepton: the di-tau, for example. Necessary to compute input variables for MVA selection
0010         '''
0011         self.cjvPtCut = cjvPtCut
0012         self.vbfMvaCalc = vbfMvaCalc
0013         self.jets = jets
0014         # the MET is taken from the di-lepton, because it can depend on it
0015         # e.g. recoil corrections, mva met
0016         self.met = diLepton.met()
0017         self.leadJets = jets[:2] # taking first 2 jets (leading ones)
0018         self.otherJets = jets[2:]
0019         self.centralJets = self.findCentralJets( self.leadJets, self.otherJets )
0020
0021         # delta eta
0022         self.deta = self.leadJets[0].eta() - self.leadJets[1].eta()
0023
0024         # below, the variables for the MVA selection
0025         # delta phi
0026         self.dphi = deltaPhi(self.leadJets[0].phi(), self.leadJets[1].phi())
0027         dijetp4 = self.leadJets[0].p4() + self.leadJets[1].p4()
0028         # mass of the di-jet system
0029         self.mjj = dijetp4.M()
0030         # pt of di-jet system
0031         self.dijetpt = dijetp4.pt()
0032         # phi of di-jet system
0033         self.dijetphi = dijetp4.phi()
0034         # higgs momentum (defined as the di-lepton momentum + the met momentum)
0035         # don't access longitudinal quantities!
0036         self.higgsp4 = diLepton.p4() + self.met.p4()
0037         # delta phi between dijet system and higgs system
0038         self.dphidijethiggs = deltaPhi( self.dijetphi, self.higgsp4.phi() )
0039         # ?
0040         visDiLepton = diLepton.leg1 ().p4 () + diLepton.leg2 ().p4 ()
0041         self.visjeteta = min (
0042             abs (self.leadJets[0].eta () - visDiLepton.eta ()),
0043             abs (self.leadJets[1].eta () - visDiLepton.eta ()))
0044         # visible higgs pt = di-lepton pt
0045         self.ptvis = visDiLepton.pt()
0046         ## self.ptvis = diLepton.pt()
0047         # new VBF MVA, based on 4 variables
0048         if self.vbfMvaCalc is not None:
0049             self.mva = self.vbfMvaCalc.val( self.mjj,
0050                                             abs(self.deta),
0051                                             self.visjeteta,
0052                                             self.ptvis )
0053         else:
0054             self.mva = -99.
0055
0056 #  double mjj      , // the invariant mass of the two tag jets
0057 #  double dEta     , // the pseudorapidity difference between the two tag jets
0058 #  double dPhi     , // the phi difference between the two tag jets
0059 #  double ditau_pt , // the vector sum of the pT of the tau + electron/muon + MET
0060 #  double dijet_pt , // the vector sum of the pT of the two tag jets
0061 #  double dPhi_hj  , // the phi difference between the di-tau vector and the di-jet vector
0062 #  double C1       , // the pseudorapidity difference between the *visible* di-tau vector and the closest tag jet
0063 #  double C2         // the *visible* pT of the di-tau
0064
0065
0066     def findCentralJets( self, leadJets, otherJets ):
0067         '''Finds all jets between the 2 leading jets, for central jet veto.'''
0068         if not len(otherJets):
0069             return []
0070         etamin = leadJets[0].eta()
0071         etamax = leadJets[1].eta()
0072         if etamin > etamax:
0073             etamin, etamax = etamax, etamin
0074         def isCentral( jet ):
0075             if jet.pt()<self.cjvPtCut:
0076                 return False
0077             eta = jet.eta()
0078             if etamin < eta and eta < etamax:
0079                 return True
0080             else:
0081                 return False
0082         centralJets = list(filter( isCentral, otherJets ))
0083         return centralJets
0084
0085     def calcP4(self, jets):
0086         '''returns the sum p4 of a collection of objects.
0087         FIXME: remove this function, which is a bit stupid
0088         '''
0089         p4 = TLorentzVector()
0090         for jet in jets:
0091             p4 += TLorentzVector(jet.px(), jet.py(), jet.pz(), jet.energy())
0092         return p4
0093
0094     def __str__(self):
0095         header = 'VBF : deta={deta:4.2f}, Mjj={mjj:4.2f}, #centjets={ncentjets}'
0096         header = header.format( deta=self.deta, mjj=self.mjj, ncentjets=len(self.centralJets))
0097         leadJets = map( str, self.leadJets )
0098         centralJets = map( str, self.centralJets)
0099         tmp = [header]
0100         tmp.append('MVA input variables: dphi={dphi:4.2f}, dijetpt={dijetpt:4.2f}, dijetphi={dijetphi:4.2f}, dphidijethiggs={dphidijethiggs:4.2f}, visjeteta={visjeteta:4.2f}, ptvis={ptvis:4.2f}'.format(
0101             dphi = self.dphi,
0102             dijetpt = self.dijetpt,
0103             dijetphi = self.dijetphi,
0104             dphidijethiggs = self.dphidijethiggs,
0105             visjeteta = self.visjeteta,
0106             ptvis = self.ptvis
0107             ))
0108         tmp.append('Leading Jets:')
0109         tmp.extend( leadJets )
0110         tmp.append('Central Jets:')
0111         tmp.extend( centralJets )
0112         return '\n'.join( tmp )