/usr/include/ThePEG/Helicity/VectorSpinInfo.h is in libthepeg-dev 1.8.0-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 | // -*- C++ -*-
//
// VectorSpinInfo.h is a part of ThePEG - Toolkit for HEP Event Generation
// Copyright (C) 2003-2011 Peter Richardson, Leif Lonnblad
//
// ThePEG is licenced under version 2 of the GPL, see COPYING for details.
// Please respect the MCnet academic guidelines, see GUIDELINES for details.
//
#ifndef THEPEG_VectorSpinInfo_H
#define THEPEG_VectorSpinInfo_H
// This is the declaration of the VectorSpinInfo class.
#include "ThePEG/EventRecord/SpinInfo.h"
#include "ThePEG/Helicity/LorentzPolarizationVector.h"
#include "VectorSpinInfo.fh"
namespace ThePEG {
namespace Helicity {
/**
* The VectorSpinInfo class is the implementation of the spin
* information for vector particles. It inherits from the SpinInfo
* class and implements the storage of the basis vectors.
*
* These basis states should be set by either matrixelements or
* decayers which are capable of generating spin correlation
* information.
*
* The basis states in the rest frame of the particles can then be
* accessed by decayers to produce the correct correlation.
*
* N.B. in our convention 0 is the \f$-1\f$ helicity state,
* 1 is the \f$0\f$ helicity state and
* 2 is the \f$+1\f$ helicity state.
*
* @author Peter Richardson
*
*/
class VectorSpinInfo: public SpinInfo {
public:
/** @name Standard constructors and destructors. */
//@{
/**
* Default constructor.
*/
VectorSpinInfo() : SpinInfo(PDT::Spin1), _productionstates(3),
_decaystates(3), _currentstates(3),
_decaycalc(false) {}
/**
* Standard Constructor.
* @param p the production momentum.
* @param time true if the particle is time-like.
*/
VectorSpinInfo(const Lorentz5Momentum & p, bool time)
: SpinInfo(PDT::Spin1, p, time),
_productionstates(3), _decaystates(3), _currentstates(3),
_decaycalc(false) {}
//@}
public:
/** @name Set and get methods for the basis state. */
//@{
/**
* Set the basis state, this is production state.
* @param hel the helicity (0,1,2 as described above.)
* @param in the LorentzPolarizationVector for the given helicity.
*/
void setBasisState(unsigned int hel,
const LorentzPolarizationVector & in) const {
assert(hel<3);
_productionstates[hel] = in;
_currentstates [hel] = in;
}
/**
* Set the basis state for the decay.
* @param hel the helicity (0,1,2 as described above.)
* @param in the LorentzPolarizationVector for the given helicity.
*/
void setDecayState(unsigned int hel,
const LorentzPolarizationVector & in) const {
assert(hel<3);
_decaycalc = true;
_decaystates[hel] = in;;
}
/**
* Get the basis state for the production for the given helicity, \a
* hel (0,1,2 as described above.)
*/
const LorentzPolarizationVector & getProductionBasisState(unsigned int hel) const {
assert(hel<3);
return _productionstates[hel];
}
/**
* Get the basis state for the decay for the given helicity, \a hel
* (0,1,2 as described above.)
*/
const LorentzPolarizationVector & getDecayBasisState(unsigned int hel) const {
assert(hel<3);
if(!_decaycalc) {
for(unsigned int ix=0;ix<3;++ix)
_decaystates[ix]=_currentstates[ix].conjugate();
_decaycalc=true;
}
// return the basis function
return _decaystates[hel];
}
//@}
/**
* Perform a Lorentz rotation of the spin information
*/
virtual void transform(const LorentzMomentum &,const LorentzRotation & );
public:
/**
* Standard Init function used to initialize the interfaces.
*/
static void Init();
/**
* Standard clone method.
*/
virtual EIPtr clone() const;
private:
/**
* Describe a concrete class without persistent data.
*/
static NoPIOClassDescription<VectorSpinInfo> initVectorSpinInfo;
/**
* Private and non-existent assignment operator.
*/
VectorSpinInfo & operator=(const VectorSpinInfo &);
private:
/**
* Basis states in the frame in which the particle was produced.
*/
mutable vector<LorentzPolarizationVector> _productionstates;
/**
* Basis states in the frame in which the particle decays.
*/
mutable vector<LorentzPolarizationVector> _decaystates;
/**
* Basis states in the current frame of the particle
*/
mutable vector<LorentzPolarizationVector> _currentstates;
/**
* True if the decay state has been set.
*/
mutable bool _decaycalc;
};
}
}
namespace ThePEG {
/** @cond TRAITSPECIALIZATIONS */
/**
* This template specialization informs ThePEG about the base class of
* VectorSpinInfo.
*/
template <>
struct BaseClassTrait<ThePEG::Helicity::VectorSpinInfo,1>
: public ClassTraitsType {
/** Typedef of the base class of VectorSpinInfo. */
typedef ThePEG::SpinInfo NthBase;
};
/**
* This template specialization informs ThePEG about the name of the
* VectorSpinInfo class and the shared object where it is defined.
*/
template <>
struct ClassTraits<ThePEG::Helicity::VectorSpinInfo>
: public ClassTraitsBase<ThePEG::Helicity::VectorSpinInfo> {
/**
* Return the class name.
*/
static string className() { return "ThePEG::Helicity::VectorSpinInfo"; }
};
/** @endcond */
}
#endif /* THEPEG_VectorSpinInfo_H */
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