MEzCalculator Class Reference

#include <MEzCalculator.h>

Public Member Functions
double	Calculate (int type=1)
	member functions More...
bool	IsComplex () const
	check for complex root More...
	MEzCalculator ()
	constructor More...
void	Print ()
	verbose More...
void	SetLepton (const pat::Particle &lepton, bool isMuon=true)
	Set lepton. More...
void	SetLepton (const TLorentzVector &lepton)
void	SetMET (const pat::MET &MET)
	Set MET. More...
void	SetMET (const TLorentzVector &MET)
	~MEzCalculator ()
	destructor More...

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

Detailed Description

---

class: MEzCalculator.h

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

version

Id:

MEzCalculator.h,v 1.4 2009/02/18 21:31:15 yumiceva Exp

---

Definition at line 18 of file MEzCalculator.h.

Constructor & Destructor Documentation

MEzCalculator::MEzCalculator

(

)

constructor

Definition at line 5 of file MEzCalculator.cc.

References isComplex_, and isMuon_.

                             {
  isComplex_ = false;
  isMuon_ = true;
}

MEzCalculator::~MEzCalculator

(

)

destructor

Definition at line 11 of file MEzCalculator.cc.

{}

Member Function Documentation

double MEzCalculator::Calculate

(

int

type = 1

)

member functions

Calculate MEz options to choose roots from quadratic equation: type = 0 : 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 (default): 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.

Definition at line 14 of file MEzCalculator.cc.

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

Referenced by TtSemiLRSignalSelObservables::operator()(), and TtSemiLepJetCombWMassDeltaTopMass::produce().

                                        {
  if (type < 0 || type > 3)
    throw cms::Exception("UnimplementedFeature") << "Type " << type << " not supported in MEzCalculator.\n";

  double M_W = 80.4;
  double M_mu = 0.10566;
  double M_e = 0.511e-3;
  double M_lepton = M_mu;
  if (!isMuon_)
    M_lepton = M_e;

  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.;

  // use pznu = - B/2*A +/- sqrt(B*B-4*A*C)/(2*A)

  double a = M_W * M_W - M_lepton * M_lepton + 2.0 * (pxmu * pxnu + 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
  } else {
    isComplex_ = false;
    double tmpsol1 = (-B + TMath::Sqrt(tmproot)) / (2.0 * A);
    double tmpsol2 = (-B - TMath::Sqrt(tmproot)) / (2.0 * A);

    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 MEzCalculator::IsComplex ( ) const

inline

check for complex root

Definition at line 51 of file MEzCalculator.h.

References isComplex_.

{ return isComplex_; };

void MEzCalculator::Print ( void  )

inline

verbose

Definition at line 53 of file MEzCalculator.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 MEzCalculator::SetLepton ( const pat::Particle &  lepton, bool  isMuon = true  )

inline

Set lepton.

Definition at line 31 of file MEzCalculator.h.

References reco::isMuon(), isMuon_, and lepton_.

Referenced by TtSemiLRSignalSelObservables::operator()(), and TtSemiLepJetCombWMassDeltaTopMass::produce().

                                                                {
    lepton_ = lepton;
    isMuon_ = isMuon;
  };

void MEzCalculator::SetLepton ( const TLorentzVector &  lepton )

inline

Definition at line 35 of file MEzCalculator.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);
  }

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

inline

Set MET.

Definition at line 25 of file MEzCalculator.h.

References HLT_FULL_cff::MET, and MET_.

Referenced by TtSemiLRSignalSelObservables::operator()(), and TtSemiLepJetCombWMassDeltaTopMass::produce().

{ MET_ = MET; };

void MEzCalculator::SetMET ( const TLorentzVector &  MET )

inline

Definition at line 26 of file MEzCalculator.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);
  }

Member Data Documentation

bool MEzCalculator::isComplex_

private

Definition at line 59 of file MEzCalculator.h.

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

bool MEzCalculator::isMuon_

private

Definition at line 62 of file MEzCalculator.h.

Referenced by Calculate(), MEzCalculator(), and SetLepton().

pat::Particle MEzCalculator::lepton_

private

Definition at line 60 of file MEzCalculator.h.

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

pat::MET MEzCalculator::MET_

private

Definition at line 61 of file MEzCalculator.h.

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