METzCalculator Class Reference

#include <METzCalculator.h>

Public Member Functions
double	Calculate (int type=0)
	member functions More...
bool	IsComplex () const
	check for complex root More...
	METzCalculator ()
	constructor More...
void	Print ()
void	SetMET (const pat::MET &MET)
	Set MET. More...
void	SetMET (const TLorentzVector &MET)
void	SetMuon (const pat::Particle &lepton)
	Set Muon. More...
void	SetMuon (const TLorentzVector &lepton)
virtual	~METzCalculator ()
	destructor More...

Private Attributes
bool	isComplex_
pat::Particle	lepton_
pat::MET	MET_

Detailed Description

---

class: METzCalculator.h

author: Francisco Yumiceva, Fermilab (yumic.nosp@m.eva@.nosp@m.fnal..nosp@m.gov)

version

Id:

METzCalculator.h,v 1.3 2009/07/30 06:02:19 jengbou Exp

---

Definition at line 21 of file METzCalculator.h.

Constructor & Destructor Documentation

METzCalculator::METzCalculator

(

)

constructor

Definition at line 6 of file METzCalculator.cc.

References isComplex_.

                               {
    isComplex_ = false;
}

METzCalculator::~METzCalculator ( )

virtual

destructor

Definition at line 11 of file METzCalculator.cc.

                                {
}

Member Function Documentation

double METzCalculator::Calculate

(

int

type = 0

)

member functions

Calculate MEz options to choose roots from quadratic equation: type = 0 (defalut): if real roots, pick the one nearest to the lepton Pz except when the Pz so chosen is greater than 300 GeV in which case pick the most central root. type = 1: if real roots, choose the one closest to the lepton Pz if complex roots, use only the real part. type = 2: if real roots, choose the most central solution. if complex roots, use only the real part. type = 3: if real roots, pick the largest value of the cosine*

Definition at line 16 of file METzCalculator.cc.

References funct::A, a, funct::C, reco::LeafCandidate::energy(), isComplex_, lepton_, MET_, reco::LeafCandidate::px(), reco::LeafCandidate::py(), and reco::LeafCandidate::pz().

Referenced by BoostedTopProducer::produce().

                                  {

    double M_W  = 80.4;
        double M_mu =  0.10566;
        double emu = lepton_.energy();
        double pxmu = lepton_.px();
        double pymu = lepton_.py();
        double pzmu = lepton_.pz();
        double pxnu = MET_.px();
        double pynu = MET_.py();
        double pznu = 0.;

        
        double a = M_W*M_W - M_mu*M_mu + 2.0*pxmu*pxnu + 2.0*pymu*pynu;
        double A = 4.0*(emu*emu - pzmu*pzmu);
        double B = -4.0*a*pzmu;
        double C = 4.0*emu*emu*(pxnu*pxnu + pynu*pynu) - a*a;

        double tmproot = B*B - 4.0*A*C;

        if (tmproot<0) {
                isComplex_= true;
                pznu = - B/(2*A); // take real part of complex roots

        //std::cout << " Neutrino Solutions: complex, real part " << pznu << std::endl;
        }
        else {
            isComplex_ = false;
            double tmpsol1 = (-B + TMath::Sqrt(tmproot))/(2.0*A);
            double tmpsol2 = (-B - TMath::Sqrt(tmproot))/(2.0*A);

            //std::cout << " Neutrino Solutions: " << tmpsol1 << ", " << tmpsol2 << std::endl;
            
            if (type == 0 ) {
                // two real roots, pick the one closest to pz of muon
                if (TMath::Abs(tmpsol2-pzmu) < TMath::Abs(tmpsol1-pzmu)) { pznu = tmpsol2;}
                else pznu = tmpsol1;
                // if pznu is > 300 pick the most central root
                if ( pznu > 300. ) {
                    if (TMath::Abs(tmpsol1)<TMath::Abs(tmpsol2) ) pznu = tmpsol1;
                    else pznu = tmpsol2;
                }
            }
            if (type == 1 ) {
                // two real roots, pick the one closest to pz of muon
                if (TMath::Abs(tmpsol2-pzmu) < TMath::Abs(tmpsol1-pzmu)) { pznu = tmpsol2;}
                else pznu = tmpsol1;
            }
            if (type == 2 ) {
                // pick the most central root.
                if (TMath::Abs(tmpsol1)<TMath::Abs(tmpsol2) ) pznu = tmpsol1;
                else pznu = tmpsol2;
            }
            if (type == 3 ) {
                // pick the largest value of the cosine
                TVector3 p3w, p3mu;
                p3w.SetXYZ(pxmu+pxnu, pymu+pynu, pzmu+ tmpsol1);
                p3mu.SetXYZ(pxmu, pymu, pzmu );
                
                double sinthcm1 = 2.*(p3mu.Perp(p3w))/M_W;
                p3w.SetXYZ(pxmu+pxnu, pymu+pynu, pzmu+ tmpsol2);
                double sinthcm2 = 2.*(p3mu.Perp(p3w))/M_W;

                double costhcm1 = TMath::Sqrt(1. - sinthcm1*sinthcm1);
                double costhcm2 = TMath::Sqrt(1. - sinthcm2*sinthcm2);

                if ( costhcm1 > costhcm2 ) pznu = tmpsol1;
                else pznu = tmpsol2;
            }
        
        }

        //Particle neutrino;
        //neutrino.setP4( LorentzVector(pxnu, pynu, pznu, TMath::Sqrt(pxnu*pxnu + pynu*pynu + pznu*pznu ))) ;

        return pznu;
}

bool METzCalculator::IsComplex ( ) const

inline

check for complex root

Definition at line 54 of file METzCalculator.h.

References isComplex_.

{ return isComplex_; };

void METzCalculator::Print ( void  )

inline

Definition at line 56 of file METzCalculator.h.

References gather_cfg::cout, lepton_, MET_, reco::LeafCandidate::px(), reco::LeafCandidate::py(), and reco::LeafCandidate::pz().

                 {
        std::cout << " METzCalculator: pxmu = " << lepton_.px() << " pzmu= " << lepton_.pz() << std::endl;
        std::cout << " METzCalculator: pxnu = " << MET_.px() << " pynu= " << MET_.py() << std::endl;
    }

void METzCalculator::SetMET ( const pat::MET &  MET )

inline

Set MET.

Definition at line 30 of file METzCalculator.h.

References MET_.

Referenced by BoostedTopProducer::produce().

{ MET_ = MET; } ;

void METzCalculator::SetMET ( const TLorentzVector &  MET )

inline

Definition at line 31 of file METzCalculator.h.

References MET_, AlCaHLTBitMon_ParallelJobs::p, and reco::LeafCandidate::setP4().

                                           {
        pat::Particle::LorentzVector p(MET.Px(),MET.Py(),MET.Pz(),MET.E());
        MET_.setP4(p);
    }

void METzCalculator::SetMuon ( const pat::Particle &  lepton )

inline

Set Muon.

Definition at line 36 of file METzCalculator.h.

References lepton_.

Referenced by BoostedTopProducer::produce().

{ lepton_ = lepton; };

void METzCalculator::SetMuon ( const TLorentzVector &  lepton )

inline

Definition at line 37 of file METzCalculator.h.

References lepton_, AlCaHLTBitMon_ParallelJobs::p, and reco::LeafCandidate::setP4().

                                               {
        pat::Particle::LorentzVector p(lepton.Px(), lepton.Py(), lepton.Pz(), lepton.E() );
        lepton_.setP4(p);
    }

Member Data Documentation

bool METzCalculator::isComplex_

private

Definition at line 63 of file METzCalculator.h.

Referenced by Calculate(), IsComplex(), and METzCalculator().

pat::Particle METzCalculator::lepton_

private

Definition at line 64 of file METzCalculator.h.

Referenced by Calculate(), Print(), and SetMuon().

pat::MET METzCalculator::MET_

private

Definition at line 65 of file METzCalculator.h.

Referenced by Calculate(), Print(), and SetMET().