P4BasePtEtaPhiM Class Reference

P4BasePtEtaPhiM is a base class for classes with 4-momentum behavior, for which pt, eta, phi and M are natural parameters, which is typically the case for a ger object. More...

#include <P4BasePtEtaPhiM.h>

Inheritance diagram for P4BasePtEtaPhiM:

Collaboration diagram for P4BasePtEtaPhiM:

Public Member Functions
virtual	~P4BasePtEtaPhiM ()
	virtual destructor needed for inheritance
double	px () const
	{@ a la I4Momentum -like interface
double	py () const
double	pz () const
virtual double	m () const =0
double	m2 () const
double	p () const
double	p2 () const
virtual double	eta () const =0
virtual double	phi () const =0
double	e () const
double	et () const
virtual double	pt () const =0
double	iPt () const
double	rapidity () const
double	cosPhi () const
double	sinPhi () const
double	tanTh () const
double	cosTh () const
double	sinTh () const
double	cotTh () const
CLHEP::HepLorentzVector	hlv () const
std::ostream &	dump (std::ostream &out) const
	Print I4Momentum content.

Detailed Description

P4BasePtEtaPhiM is a base class for classes with 4-momentum behavior, for which pt, eta, phi and M are natural parameters, which is typically the case for a ger object.

Any class deriving from it should implement pt(), eta(), phi(), m().

Author

Olga Igonkina olya@.nosp@m.cern.nosp@m..ch

Definition at line 32 of file P4BasePtEtaPhiM.h.

Constructor & Destructor Documentation

~P4BasePtEtaPhiM()

P4BasePtEtaPhiM::~P4BasePtEtaPhiM ( )

inlinevirtual

virtual destructor needed for inheritance

Definition at line 92 of file P4BasePtEtaPhiM.h.

{}

Member Function Documentation

cosPhi()

double P4BasePtEtaPhiM::cosPhi ( ) const

inline

Definition at line 172 of file P4BasePtEtaPhiM.h.

{
 return std::cos(this->phi());
}

cosTh()

double P4BasePtEtaPhiM::cosTh ( ) const

inline

Definition at line 184 of file P4BasePtEtaPhiM.h.

{ 
  return std::tanh(this->eta());
}

cotTh()

double P4BasePtEtaPhiM::cotTh ( ) const

inline

Definition at line 201 of file P4BasePtEtaPhiM.h.

{ 
  return std::sinh(this->eta());
}

dump()

std::ostream & P4BasePtEtaPhiM::dump ( std::ostream & out ) const

inline

Print I4Momentum content.

Definition at line 236 of file P4BasePtEtaPhiM.h.

{
  std::stringstream s;
  s << "[pt,eta,phi,m] ="
    << std::right << std::scientific << std::setprecision(8) 
    << std::setw(16) << this->pt()
    << std::setw(16) << this->eta()
    << std::setw(16) << this->phi()
    << std::setw(16) << this->m();
 
  out << s.str();
  return out;
}

e()

double P4BasePtEtaPhiM::e ( ) const

inline

Definition at line 141 of file P4BasePtEtaPhiM.h.

{
  const double theMass = this->m();
  const double thePt   = this->pt();
  const double thePz   = this->pz();
 
  //DR from Frank Paige
  // if negative pt point in the opposite direction
  // BUT eta and phi still the same !!!
 
  const double eSign = (thePt >= 0.) ? +1. : -1.;
  return eSign * std::sqrt( thePt*thePt + thePz*thePz +  theMass*theMass);
}

et()

double P4BasePtEtaPhiM::et ( ) const

inline

Definition at line 155 of file P4BasePtEtaPhiM.h.

{
  return this->e()*this->sinTh();
}

eta()

virtual double P4BasePtEtaPhiM::eta ( ) const

pure virtual

Implemented in P4Impl< P4ImplPtEtaPhiM >, and P4ImplPtEtaPhiM.

hlv()

CLHEP::HepLorentzVector P4BasePtEtaPhiM::hlv ( ) const

inline

Definition at line 217 of file P4BasePtEtaPhiM.h.

{
  //minimize the number of calculation and dereference
  const double theM = this->m();
  // note that pt can have negative sign : then it points in opposite direction but eta and phi are still on the same side
  const double thePt = this->pt();  
  
 
  const double thePx = thePt*this->cosPhi();
  const double thePy = thePt*this->sinPhi();
 
  const double thePz = thePt*this->cotTh();
  
  const double theE=std::sqrt(thePt*thePt+thePz*thePz+theM*theM);
  
 
  return CLHEP::HepLorentzVector( thePx, thePy, thePz, theE );
}

iPt()

double P4BasePtEtaPhiM::iPt ( ) const

inline

Definition at line 160 of file P4BasePtEtaPhiM.h.

{ 
  return 1./this->pt();
}

m()

virtual double P4BasePtEtaPhiM::m ( ) const

pure virtual

Implemented in P4Impl< P4ImplPtEtaPhiM >, and P4ImplPtEtaPhiM.

m2()

double P4BasePtEtaPhiM::m2 ( ) const

inline

Definition at line 110 of file P4BasePtEtaPhiM.h.

{ 
  const double mass = this->m();
  return mass*mass;
}

p()

double P4BasePtEtaPhiM::p ( ) const

inline

Definition at line 116 of file P4BasePtEtaPhiM.h.

{ 
  const double thePt = this->pt();
  const double thePz = this->pz();
 
  //DR from Frank Paige
  // if negative pt point in the opposite direction
  // BUT eta and phi still the same !!!
 
  const double eSign = (thePt >= 0.) ? +1. : -1.;
  return eSign * std::sqrt( thePt*thePt + thePz*thePz );
}

p2()

double P4BasePtEtaPhiM::p2 ( ) const

inline

Definition at line 129 of file P4BasePtEtaPhiM.h.

{ 
  // This method has been implemented so as to give the same as would be 
  // obtained from pow((this->p()),2) with this->p() implemented according to 
  // Frank Paige's algorithm above. 
 
  const double pt = this->pt();
  const double pz = this->pz();
 
  return pt*pt + pz*pz;
}

phi()

virtual double P4BasePtEtaPhiM::phi ( ) const

pure virtual

Implemented in P4Impl< P4ImplPtEtaPhiM >, and P4ImplPtEtaPhiM.

pt()

virtual double P4BasePtEtaPhiM::pt ( ) const

pure virtual

Implemented in P4Impl< P4ImplPtEtaPhiM >, and P4ImplPtEtaPhiM.

px()

double P4BasePtEtaPhiM::px ( ) const

inline

{@ a la I4Momentum -like interface

Definition at line 95 of file P4BasePtEtaPhiM.h.

{ 
  return this->pt() * std::cos(this->phi());
}

py()

double P4BasePtEtaPhiM::py ( ) const

inline

Definition at line 100 of file P4BasePtEtaPhiM.h.

{ 
  return this->pt() * std::sin(this->phi());
}

pz()

double P4BasePtEtaPhiM::pz ( ) const

inline

Definition at line 105 of file P4BasePtEtaPhiM.h.

{ 
  return this->pt()/this->tanTh();
}

rapidity()

double P4BasePtEtaPhiM::rapidity ( ) const

inline

Definition at line 165 of file P4BasePtEtaPhiM.h.

  {
    const double theE=this->e();
    const double thePz=this->pz();
    return 0.5*std::log((theE+thePz)/(theE-thePz));
   }

sinPhi()

double P4BasePtEtaPhiM::sinPhi ( ) const

inline

Definition at line 177 of file P4BasePtEtaPhiM.h.

{
 return std::sin(this->phi());
}

sinTh()

double P4BasePtEtaPhiM::sinTh ( ) const

inline

Definition at line 189 of file P4BasePtEtaPhiM.h.

{ 
  // avoid numeric overflow if very large eta
 
  double aEta=std::abs(this->eta());
  if ( aEta>710) {
    aEta=710;
  }
 
  return 1./std::cosh(aEta);
}

tanTh()

double P4BasePtEtaPhiM::tanTh ( ) const

inline

Definition at line 206 of file P4BasePtEtaPhiM.h.

{
 return 1./std::sinh(this->eta());
}

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The documentation for this class was generated from the following file:

• P4BasePtEtaPhiM.h