| 1 | //--------------------------------------------------------------------------
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| 2 | #ifndef HEPMC_POLARIZATION_H
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| 3 | #define HEPMC_POLARIZATION_H
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| 4 |
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| 5 | //////////////////////////////////////////////////////////////////////////
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| 6 | // Matt.Dobbs@Cern.CH, September 1999, refer to:
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| 7 | // M. Dobbs and J.B. Hansen, "The HepMC C++ Monte Carlo Event Record for
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| 8 | // High Energy Physics", Computer Physics Communications (to be published).
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| 9 | //
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| 10 | // Polarization object for a particle. All angles are in radians.
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| 11 | //////////////////////////////////////////////////////////////////////////
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| 12 |
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| 13 | #include "SimpleVector.h"
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| 14 | #include <iostream>
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| 15 | #include <cmath>
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| 16 |
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| 17 | namespace HepMC {
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| 18 |
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| 19 | static const double HepMC_pi = 3.14159265358979323846; // copy of pi from CLHEP
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| 20 |
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| 21 | //! The Polarization class stores theta and phi for a GenParticle
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| 22 |
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| 23 | ///
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| 24 | /// \class Polarization
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| 25 | /// HepMC::Polarization stores a particle's theta and phi in radians.
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| 26 | /// Use of this information is optional.
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| 27 | /// By default, the polarization is set to zero.
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| 28 | ///
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| 29 | class Polarization {
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| 30 |
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| 31 | /// print polarization information
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| 32 | friend std::ostream& operator<<( std::ostream&, const Polarization& );
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| 33 |
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| 34 | public:
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| 35 | /// default constructor
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| 36 | Polarization( );
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| 37 | /// constructor requiring at least one value
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| 38 | Polarization( double theta, double phi = 0 );
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| 39 | /// construct from another polarization object
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| 40 | Polarization( const Polarization& inpolar );
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| 41 | /// construct using the polar and azimuthal angles from a ThreeVector
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| 42 | Polarization( const ThreeVector& vec3in );
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| 43 | virtual ~Polarization() {}
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| 44 |
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| 45 | /// swap
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| 46 | void swap( Polarization & other);
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| 47 | /// make a copy
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| 48 | Polarization& operator=( const Polarization& inpolar );
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| 49 | /// equality requires that theta and phi are equal
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| 50 | bool operator==( const Polarization& ) const;
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| 51 | /// inequality results if either theta or phi differ
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| 52 | bool operator!=( const Polarization& ) const;
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| 53 |
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| 54 | /// print theta and phi
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| 55 | void print( std::ostream& ostr = std::cout ) const;
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| 56 |
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| 57 | ////////////////////
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| 58 | // access methods //
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| 59 | ////////////////////
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| 60 | double theta() const; //!< returns polar angle in radians
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| 61 | double phi() const; //!< returns azimuthal angle in radians
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| 62 | ThreeVector normal3d() const; //!< unit 3 vector for easy manipulation
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| 63 | bool is_defined() const; //!< returns true if the Polarization has been defined
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| 64 |
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| 65 | /// set polar angle in radians
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| 66 | double set_theta( double theta );
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| 67 | /// set azimuthal angle in radians
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| 68 | double set_phi( double phi );
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| 69 | /// set both polar and azimuthal angles in radians
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| 70 | void set_theta_phi( double theta, double phi );
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| 71 | /// sets polarization according to direction of 3 vec
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| 72 | ThreeVector set_normal3d( const ThreeVector& vec3in );
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| 73 | /// declares the Polarization as undefined and zeros the values
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| 74 | void set_undefined();
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| 75 |
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| 76 | private:
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| 77 | /// private method to return a polar angle in the correct range
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| 78 | double valid_theta( double theta );
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| 79 | /// private method to return an azimuthal angle in the correct range
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| 80 | double valid_phi( double phi );
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| 81 |
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| 82 | private:
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| 83 | double m_theta; //polar angle of polarization in radians 0< theta <pi
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| 84 | double m_phi; //azimuthal angle of polarization in rad. 0< phi <2pi
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| 85 | bool m_defined; //used to flag if the Polarization has been defined
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| 86 | };
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| 87 |
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| 88 | ///////////////////////////
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| 89 | // INLINE Access Methods //
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| 90 | ///////////////////////////
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| 91 |
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| 92 | inline double Polarization::theta() const { return m_theta; }
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| 93 | inline double Polarization::phi() const { return m_phi; }
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| 94 |
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| 95 | ///////////////////////////
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| 96 | // INLINE Operators //
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| 97 | ///////////////////////////
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| 98 |
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| 99 | inline bool Polarization::operator==( const Polarization& a ) const
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| 100 | {
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| 101 | return ( a.theta() == this->theta() && a.phi() == this->phi() && a.is_defined() == this->is_defined() );
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| 102 | }
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| 103 |
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| 104 | inline bool Polarization::operator!=(const Polarization& a ) const
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| 105 | {
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| 106 | return !( a == *this );
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| 107 | }
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| 108 |
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| 109 | } // HepMC
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| 110 |
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| 111 | #endif // HEPMC_POLARIZATION_H
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| 112 | //--------------------------------------------------------------------------
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