ATOOLS/Phys/Momentum_Shifter.H

0001 #ifndef ATOOLS_Phys_Momentum_Shifter_H
0002 #define ATOOLS_Phys_Momentum_Shifter_H
0003
0004 #include "ATOOLS/Phys/Particle.H"
0005 #include "ATOOLS/Math/Poincare.H"
0006
0007 #include <set>
0008
0009 namespace ATOOLS {
0010
0011   struct ms {
0012
0013     enum error_code {
0014       no_error        =   0,
0015       shift_error     =   1,
0016       direction_error =   2,
0017       sperp_error     =   4,
0018       momenta_error   =   8,
0019       boost_error_1   =  16,
0020       boost_error_2   =  32,
0021       scale_error     =  64,
0022       setup_error     = 128
0023     };
0024
0025   };// end of struct ms
0026
0027   std::ostream &operator<<(std::ostream &ostr,const ms::error_code code);
0028
0029   class Momentum_Shifter {
0030   private:
0031
0032     Vec4D m_shift, m_direction;
0033     Vec4D m_pold[3], m_pnew[3], m_pperp[3];
0034
0035     Poincare  m_oldcms, m_newcms, m_rotate;
0036     Particle *p_initial[2];
0037
0038     std::set<Particle*> m_boosted;
0039
0040     size_t m_maxdepth;
0041     double m_sp[3];
0042     bool   m_setshift, m_setdirection, m_setsp[3];
0043     bool   m_initboost, m_initscale;
0044
0045     bool CalculateShift();
0046     bool DetermineDirection();
0047     bool CalculateSPerp();
0048     bool ConstructMomenta();
0049
0050     bool Boost(Particle *const particle,const size_t catcher);
0051     bool BoostBack(Particle *const particle,const size_t catcher);
0052
0053   public:
0054
0055     // constructor
0056     Momentum_Shifter(Particle *const initial1,Particle *const initial2);
0057
0058     // member functions
0059     double Lambda2(double sp,double sp1,double sp2);
0060
0061     bool Boost(Particle *const particle);
0062     bool BoostBack(Particle *const particle);
0063
0064     ms::error_code Boost();
0065     ms::error_code BoostBack();
0066
0067     ms::error_code Scale();
0068
0069     void Reset();
0070
0071     // inline functions
0072     inline void SetMaxDepth(const size_t depth)    { m_maxdepth=depth;    }
0073
0074     inline void SetSPerp(const double sp,const size_t i) { m_sp[i]=sp; m_setsp[i]=true; }
0075
0076     inline void SetShift(const Vec4D &shift)   { m_shift=shift; m_setshift=true;       }
0077     inline void SetDirection(const Vec4D &dir) { m_direction=dir; m_setdirection=true; }
0078
0079     inline size_t MaxDepth() const { return m_maxdepth; }
0080
0081     inline double SPerp(const size_t i) const { return m_sp[i]; }
0082
0083     inline const Vec4D &Shift() const         { return m_shift;     }
0084     inline const Vec4D &Direction() const     { return m_direction; }
0085
0086   };// end of class Momentum_Shifter
0087
0088 }// end of namespace ATOOLS
0089
0090 #endif