ThePEG: UtilityBase.h Source File

00001 // -*- C++ -*-
00002 //
00003 // UtilityBase.h is a part of ThePEG - Toolkit for HEP Event Generation
00004 // Copyright (C) 1999-2007 Leif Lonnblad
00005 //
00006 // ThePEG is licenced under version 2 of the GPL, see COPYING for details.
00007 // Please respect the MCnet academic guidelines, see GUIDELINES for details.
00008 //
00009 #ifndef ThePEG_UtilityBase_H
00010 #define ThePEG_UtilityBase_H
00011 
00012 #include "ThePEG/Config/ThePEG.h"
00013 #include "ThePEG/EventRecord/ParticleTraits.h"
00014 #include "ThePEG/Utilities/Triplet.h"
00015 
00016 namespace ThePEG {
00017 
00024 struct UtilityBase {
00025 
00032   template <typename Cont>
00033   static LorentzMomentum sumMomentum(const Cont & c) {
00034     return sumMomentum(c.begin(), c.end());
00035   }
00036 
00043   template <typename Iterator>
00044   static LorentzMomentum sumMomentum(Iterator first, Iterator last) {
00045     LorentzMomentum sum;
00046     typedef typename std::iterator_traits<Iterator>::value_type PType;
00047     typedef ParticleTraits<PType> Traits;
00048     
00049     while ( first != last ) sum += Traits::momentum(*first++);
00050     return sum;
00051   }
00052 
00059   template <typename Iterator>
00060   static void transform(Iterator first, Iterator last,
00061                         const LorentzRotation & boost) {
00062     typedef typename std::iterator_traits<Iterator>::value_type PType;
00063     typedef ParticleTraits<PType> Traits;
00064     
00065     while ( first != last ) Traits::transform(*first++, boost);
00066   }
00067 
00074   template <typename Cont>
00075   static void transform(Cont & cont, const LorentzRotation & boost) {
00076     transform(cont.begin(), cont.end(), boost);
00077   }
00078 
00087   template <typename PType>
00088   static LorentzRotation boostToCM(const pair<PType,PType> & pp);
00089 
00098   template <typename PType>
00099   static LorentzRotation boostToCM(const Triplet<PType,PType,PType> & pt);
00100 
00108   template <typename PType>
00109   static LorentzRotation getBoostToCM(const pair<PType,PType> & pp);
00110 
00119   template <typename PType>
00120   static LorentzRotation getBoostToCM(const Triplet<PType,PType,PType> & pt);
00121 
00125   template <typename PType>
00126   static LorentzRotation getBoostFromCM(const pair<PType,PType> & pp);
00127 
00131   template <typename PType>
00132   static LorentzRotation getBoostFromCM(const Triplet<PType,PType,PType> & pt);
00133 
00141   template <typename Iterator>
00142   static LorentzRotation boostToCM(Iterator first, Iterator last) {
00143     return boostToCM(first, last, last, last);
00144   }
00145 
00155   template <typename Iterator>
00156   static LorentzRotation boostToCM(Iterator first, Iterator last, Iterator zAxis) {
00157     return boostToCM(first, last, zAxis, last);
00158   }
00159 
00170   template <typename Iterator>
00171   static LorentzRotation boostToCM(Iterator first, Iterator last,
00172                                    Iterator zAxis, Iterator xzPlane);
00173 
00182   template <typename PType>
00183   static void setMomentum(PType & p, const Momentum3 & q);
00184 
00193   template <typename PType>
00194   static void setMomentumFromCMS(PType & p, const Momentum3 & q);
00195 
00205   template <typename Iter>
00206   static void setMomentum(Iter first, Iter last, const Momentum3 & q);
00207 
00219   template <typename Iter>
00220   static void setMomentum(Iter first, Iter last,
00221                           const Momentum3 & q, double eps);
00222 
00236   template <typename Iter>
00237   static void setMomentumFromCMS(Iter first, Iter last,
00238                                  Energy2 m2, const Momentum3 & q);
00239 
00251   template <typename PType>
00252   static LorentzRotation transformToMomentum(const PType & p, 
00253                                              const Momentum3 & q) {
00254     typedef ParticleTraits<PType> Traits;
00255     LorentzMomentum q4(q, sqrt(q.mag2() + Traits::momentum(p).m2()));
00256     return transformToMomentum(p, q4);
00257   }
00258 
00269   template <typename PType>
00270   static LorentzRotation transformToMomentum(const PType & p, 
00271                                              const LorentzMomentum & q) {
00272     return transformFromCMS(q)*transformToCMS(p);
00273   }
00274 
00280   template <typename PType>
00281   static LorentzRotation getTransformToMomentum(const PType & p, 
00282                                                 const LorentzMomentum & q,
00283                                                 const LorentzMomentum & k) {
00284     typedef ParticleTraits<PType> Traits;
00285     LorentzMomentum k0 = Traits::momentum(p) - k;
00286     LorentzMomentum k1 = Traits::momentum(q) - k;
00287     return getBoostFromCM(make_pair(k1, k))*getBoostToCM(make_pair(k0, k));
00288   }
00289 
00295   template <typename PType>
00296   static LorentzRotation getTransformToMomentum(const PType & p, 
00297                                                 const Momentum3 & q,
00298                                                 const LorentzMomentum & k) {
00299     typedef ParticleTraits<PType> Traits;
00300     LorentzMomentum q4(q, sqrt(q.mag2() + Traits::momentum(p).m2()));
00301     return getTransformToMomentum(p, q4, k);
00302   }
00303 
00310   template <typename LV>
00311   static LorentzRotation transformFromCMS(const LV & p);
00312 
00320   template <typename LV>
00321   static LorentzRotation transformFromCMS(const LV & sum, LV zAxis);
00322 
00330   template <typename LV>
00331   static LorentzRotation transformFromCMS(const LV & sum,
00332                                           const LV & zAxis, LV xyPlane);
00333 
00340   template <typename LV>
00341   static LorentzRotation transformToCMS(const LV & sum, LV zAxis);
00342 
00350   template <typename LV>
00351   static LorentzRotation transformToCMS(const LV & p);
00352 
00360   template <typename LV>
00361   static LorentzRotation transformToCMS(const LV & sum,
00362                                         const LV & zAxis, LV xyPlane);
00363 
00368   template <typename Cont1, typename Cont2>
00369   static void add(Cont1 & c1, const Cont2 & c2);
00370 
00371 };
00372 
00374 struct Utilities: public UtilityBase {};
00375 
00376 }
00377 
00378 #ifndef ThePEG_TEMPLATES_IN_CC_FILE
00379 #include "UtilityBase.tcc"
00380 #endif
00381 
00382 #endif /* ThePEG_UtilityBase_H */