BsJpsiPhiAngles Class Reference

#include <BsJpsiPhiAngles.h>

Collaboration diagram for BsJpsiPhiAngles:

Public Member Functions
double	thetaK () const
double	thetaL () const
double	chi () const
double	thetatr () const
double	phitr () const
double	thetaKfix () const
double	thetaLfix () const
double	chifix () const
double	thetatrfix () const
double	phitrfix () const
	BsJpsiPhiAngles (const CLHEP::HepLorentzVector &Kplus, const CLHEP::HepLorentzVector &Muplus, const CLHEP::HepLorentzVector &Phi, const CLHEP::HepLorentzVector &Jpsi, const CLHEP::HepLorentzVector &Bs)

Private Attributes
double	m_theta1
double	m_theta2
double	m_chi
double	m_thetatr
double	m_phitr

Detailed Description

Definition at line 9 of file BsJpsiPhiAngles.h.

Constructor & Destructor Documentation

BsJpsiPhiAngles()

BsJpsiPhiAngles::BsJpsiPhiAngles ( const CLHEP::HepLorentzVector &  Kplus, const CLHEP::HepLorentzVector &  Muplus, const CLHEP::HepLorentzVector &  Phi, const CLHEP::HepLorentzVector &  Jpsi, const CLHEP::HepLorentzVector &  Bs  )

inline

Definition at line 40 of file BsJpsiPhiAngles.h.

  {
    using CLHEP::HepLorentzVector;
    using CLHEP::Hep3Vector;
 
     m_theta1  = 0.;
     m_theta2  = 0.;
     m_chi     = 0.;
     m_thetatr = 0.;
     m_phitr   = 0.;
     
     
       // 0.1 Get the Mummy1 & Mummy2 4-vectors in lab
  HepLorentzVector Mum1QV ( Phi ) ; // this should be phi
  HepLorentzVector Mum2QV ( Jpsi ) ; // this should be jpsi
  // 0.2 Boost the Mummy1 & Mummy2 to the B(aBcand) rest frame
  HepLorentzVector BQV(Bs); // this should be Bs Meson
 
  Hep3Vector Bboost ( BQV.boostVector() );
  Mum1QV.boost ( -( Bboost ) );
  Mum2QV.boost ( -( Bboost ) ); 
    // 1. Compute helicity angle theta1
  // 1.1 Boost cand1 to the B rest frame (grandMa)
  HepLorentzVector cand1QV ( Kplus );
  cand1QV.boost ( - (Bboost) );
  // 1.2 Boost now cand1 in his mother rest frame
  cand1QV.boost ( - (Mum1QV.boostVector() ) ); 
  // 1.3 compute the theta1 angle
  Hep3Vector Mum1TV = Mum1QV.boostVector(); 
  Hep3Vector cand1TV = cand1QV.boostVector();
  Hep3Vector ucand1TV = cand1TV.unit();
  m_theta1 = cand1TV.angle(Mum1TV);
  
  
  
  // 2. Compute helicity angle theta2
  // 2.1 Boost cand2 to the B rest frame (grandMa)
  HepLorentzVector cand2QV ( Muplus );
  cand2QV.boost ( - (Bboost) );
  // 2.2 Boost now cand2 in his mother rest frame
  cand2QV.boost ( - (Mum2QV.boostVector() ) ); 
  // 2.3 compute the theta2 angle
  Hep3Vector Mum2TV = Mum2QV.boostVector(); 
  Hep3Vector cand2TV = cand2QV.boostVector();
  Hep3Vector ucand2TV = cand2TV.unit();
  m_theta2 = cand2TV.angle(Mum2TV);
 
  // 3. Compute the chi angle
  // 3.1 Define the c and d vectors (see Physbook) 
  Hep3Vector c;
  Hep3Vector d;
  Hep3Vector uMum1TV = Mum1TV.unit();
  Hep3Vector uMum2TV = Mum2TV.unit();
 
  // 3.2 Calculate these vectors
  c = (uMum1TV.cross(ucand1TV)).cross(uMum1TV);
  d = (uMum2TV.cross(ucand2TV)).cross(uMum2TV);
  double sinphi = (c.cross(uMum1TV)).dot(d);
  double cosphi = c.dot(d);
  // 3.3 Now get chi = angle between the 2 decay planes
  m_chi = std::atan2(sinphi,cosphi);
  // 3.4 Put chi in [0;2pi]
  if ( m_chi < 0 )
  {
    m_chi = 2.*M_PI + m_chi;
  }
  
  // 4. Transversity angles
  double cosThetaTr = std::sin ( m_theta2 ) * std::sin ( m_chi ) ;
  double sinThetaTr = std::sqrt ( 1. - cosThetaTr * cosThetaTr ) ; 
  double cosPhiTr = std::cos(m_theta2) / sinThetaTr ;
  double sinPhiTr = std::sin(m_theta2) * std::cos( m_chi ) / sinThetaTr ;
  m_phitr   = std::atan2 ( sinPhiTr, cosPhiTr ) ;
  if (m_phitr < 0) 
  {
    m_phitr = 2.*M_PI + m_phitr;
  }
  m_thetatr = std::acos(cosThetaTr) ;
  
  
    
  }

Member Function Documentation

chi()

double BsJpsiPhiAngles::chi ( ) const

inline

Definition at line 24 of file BsJpsiPhiAngles.h.

{ return m_chi;     }

chifix()

double BsJpsiPhiAngles::chifix ( ) const

inline

Definition at line 30 of file BsJpsiPhiAngles.h.

{ return -(m_chi - M_PI) ;     }

phitr()

double BsJpsiPhiAngles::phitr ( ) const

inline

Definition at line 26 of file BsJpsiPhiAngles.h.

{ return m_phitr;   } 

phitrfix()

double BsJpsiPhiAngles::phitrfix ( ) const

inline

Definition at line 32 of file BsJpsiPhiAngles.h.

{ return -(m_phitr - M_PI);   }  

thetaK()

double BsJpsiPhiAngles::thetaK ( ) const

inline

Definition at line 22 of file BsJpsiPhiAngles.h.

{ return m_theta1;  }

thetaKfix()

double BsJpsiPhiAngles::thetaKfix ( ) const

inline

Definition at line 28 of file BsJpsiPhiAngles.h.

{ return cos(m_theta1);  }

thetaL()

double BsJpsiPhiAngles::thetaL ( ) const

inline

Definition at line 23 of file BsJpsiPhiAngles.h.

{ return m_theta2;  }

thetaLfix()

double BsJpsiPhiAngles::thetaLfix ( ) const

inline

Definition at line 29 of file BsJpsiPhiAngles.h.

{ return cos(m_theta2);  }

thetatr()

double BsJpsiPhiAngles::thetatr ( ) const

inline

Definition at line 25 of file BsJpsiPhiAngles.h.

{ return m_thetatr; }

thetatrfix()

double BsJpsiPhiAngles::thetatrfix ( ) const

inline

Definition at line 31 of file BsJpsiPhiAngles.h.

{ return -cos(m_thetatr); }

Member Data Documentation

m_chi

double BsJpsiPhiAngles::m_chi

private

Definition at line 17 of file BsJpsiPhiAngles.h.

m_phitr

double BsJpsiPhiAngles::m_phitr

private

Definition at line 19 of file BsJpsiPhiAngles.h.

m_theta1

double BsJpsiPhiAngles::m_theta1

private

Definition at line 15 of file BsJpsiPhiAngles.h.

m_theta2

double BsJpsiPhiAngles::m_theta2

private

Definition at line 16 of file BsJpsiPhiAngles.h.

m_thetatr

double BsJpsiPhiAngles::m_thetatr

private

Definition at line 18 of file BsJpsiPhiAngles.h.

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

• BsJpsiPhiAngles.h