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 9 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 12 of file METzCalculator.cc.

References MaterialEffects_cfi::A, a, Abs(), TtFullHadDaughter::B, gen::C, reco::LeafCandidate::energy(), isComplex_, lepton_, MET_, reco::LeafCandidate::px(), reco::LeafCandidate::py(), and reco::LeafCandidate::pz().

Referenced by BoostedTopProducer::produce(), and SetMuon().

                                         {
  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 53 of file METzCalculator.h.

References isComplex_.

{ return isComplex_; };

void METzCalculator::Print ( void  )

inline

Definition at line 55 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 29 of file METzCalculator.h.

References HLTTauDQMOffline_cfi::MET, and MET_.

Referenced by BoostedTopProducer::produce().

{ MET_ = MET; };

void METzCalculator::SetMET ( const TLorentzVector &  MET )

inline

Definition at line 30 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 35 of file METzCalculator.h.

References lepton_.

Referenced by BoostedTopProducer::produce().

{ lepton_ = lepton; };

void METzCalculator::SetMuon ( const TLorentzVector &  lepton )

inline

Definition at line 36 of file METzCalculator.h.

References Calculate(), 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 61 of file METzCalculator.h.

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

pat::Particle METzCalculator::lepton_

private

Definition at line 62 of file METzCalculator.h.

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

pat::MET METzCalculator::MET_

private

Definition at line 63 of file METzCalculator.h.

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