Geant4 Cross Reference

Cross-Referencing   Geant4
Geant4/processes/hadronic/models/parton_string/qgsm/src/G4SingleDiffractiveExcitation.cc

Version: [ ReleaseNotes ] [ 1.0 ] [ 1.1 ] [ 2.0 ] [ 3.0 ] [ 3.1 ] [ 3.2 ] [ 4.0 ] [ 4.0.p1 ] [ 4.0.p2 ] [ 4.1 ] [ 4.1.p1 ] [ 5.0 ] [ 5.0.p1 ] [ 5.1 ] [ 5.1.p1 ] [ 5.2 ] [ 5.2.p1 ] [ 5.2.p2 ] [ 6.0 ] [ 6.0.p1 ] [ 6.1 ] [ 6.2 ] [ 6.2.p1 ] [ 6.2.p2 ] [ 7.0 ] [ 7.0.p1 ] [ 7.1 ] [ 7.1.p1 ] [ 8.0 ] [ 8.0.p1 ] [ 8.1 ] [ 8.1.p1 ] [ 8.1.p2 ] [ 8.2 ] [ 8.2.p1 ] [ 8.3 ] [ 8.3.p1 ] [ 8.3.p2 ] [ 9.0 ] [ 9.0.p1 ] [ 9.0.p2 ] [ 9.1 ] [ 9.1.p1 ] [ 9.1.p2 ] [ 9.1.p3 ] [ 9.2 ] [ 9.2.p1 ] [ 9.2.p2 ] [ 9.2.p3 ] [ 9.2.p4 ] [ 9.3 ] [ 9.3.p1 ] [ 9.3.p2 ] [ 9.4 ] [ 9.4.p1 ] [ 9.4.p2 ] [ 9.4.p3 ] [ 9.4.p4 ] [ 9.5 ] [ 9.5.p1 ] [ 9.5.p2 ] [ 9.6 ] [ 9.6.p1 ] [ 9.6.p2 ] [ 9.6.p3 ] [ 9.6.p4 ] [ 10.0 ] [ 10.0.p1 ] [ 10.0.p2 ] [ 10.0.p3 ] [ 10.0.p4 ] [ 10.1 ] [ 10.1.p1 ] [ 10.1.p2 ] [ 10.1.p3 ] [ 10.2 ] [ 10.2.p1 ] [ 10.2.p2 ] [ 10.2.p3 ] [ 10.3 ] [ 10.3.p1 ] [ 10.3.p2 ] [ 10.3.p3 ] [ 10.4 ] [ 10.4.p1 ] [ 10.4.p2 ] [ 10.4.p3 ] [ 10.5 ] [ 10.5.p1 ] [ 10.6 ] [ 10.6.p1 ] [ 10.6.p2 ] [ 10.6.p3 ] [ 10.7 ] [ 10.7.p1 ] [ 10.7.p2 ] [ 10.7.p3 ] [ 10.7.p4 ] [ 11.0 ] [ 11.0.p1 ] [ 11.0.p2 ] [ 11.0.p3, ] [ 11.0.p4 ] [ 11.1 ] [ 11.1.1 ] [ 11.1.2 ] [ 11.1.3 ] [ 11.2 ] [ 11.2.1 ] [ 11.2.2 ] [ 11.3.0 ]

Diff markup

Differences between /processes/hadronic/models/parton_string/qgsm/src/G4SingleDiffractiveExcitation.cc (Version 11.3.0) and /processes/hadronic/models/parton_string/qgsm/src/G4SingleDiffractiveExcitation.cc (Version 9.1)


  1 //                                                  1 //
  2 // *******************************************      2 // ********************************************************************
  3 // * License and Disclaimer                         3 // * License and Disclaimer                                           *
  4 // *                                                4 // *                                                                  *
  5 // * The  Geant4 software  is  copyright of th      5 // * The  Geant4 software  is  copyright of the Copyright Holders  of *
  6 // * the Geant4 Collaboration.  It is provided      6 // * the Geant4 Collaboration.  It is provided  under  the terms  and *
  7 // * conditions of the Geant4 Software License      7 // * conditions of the Geant4 Software License,  included in the file *
  8 // * LICENSE and available at  http://cern.ch/      8 // * LICENSE and available at  http://cern.ch/geant4/license .  These *
  9 // * include a list of copyright holders.           9 // * include a list of copyright holders.                             *
 10 // *                                               10 // *                                                                  *
 11 // * Neither the authors of this software syst     11 // * Neither the authors of this software system, nor their employing *
 12 // * institutes,nor the agencies providing fin     12 // * institutes,nor the agencies providing financial support for this *
 13 // * work  make  any representation or  warran     13 // * work  make  any representation or  warranty, express or implied, *
 14 // * regarding  this  software system or assum     14 // * regarding  this  software system or assume any liability for its *
 15 // * use.  Please see the license in the file      15 // * use.  Please see the license in the file  LICENSE  and URL above *
 16 // * for the full disclaimer and the limitatio     16 // * for the full disclaimer and the limitation of liability.         *
 17 // *                                               17 // *                                                                  *
 18 // * This  code  implementation is the result      18 // * This  code  implementation is the result of  the  scientific and *
 19 // * technical work of the GEANT4 collaboratio     19 // * technical work of the GEANT4 collaboration.                      *
 20 // * By using,  copying,  modifying or  distri     20 // * By using,  copying,  modifying or  distributing the software (or *
 21 // * any work based  on the software)  you  ag     21 // * any work based  on the software)  you  agree  to acknowledge its *
 22 // * use  in  resulting  scientific  publicati     22 // * use  in  resulting  scientific  publications,  and indicate your *
 23 // * acceptance of all terms of the Geant4 Sof     23 // * acceptance of all terms of the Geant4 Software license.          *
 24 // *******************************************     24 // ********************************************************************
 25 //                                                 25 //
 26 //                                                 26 //
                                                   >>  27 // $Id: G4SingleDiffractiveExcitation.cc,v 1.1 2007/05/25 07:30:47 gunter Exp $
 27 // -------------------------------------------     28 // ------------------------------------------------------------
 28 //      GEANT 4 class implemetation file           29 //      GEANT 4 class implemetation file
 29 //                                                 30 //
 30 //      ---------------- G4SingleDiffractiveEx     31 //      ---------------- G4SingleDiffractiveExcitation --------------
 31 //             by Gunter Folger, October 1998.     32 //             by Gunter Folger, October 1998.
 32 //      diffractive Excitation used by strings     33 //      diffractive Excitation used by strings models
 33 //  Take a projectile and a target                 34 //  Take a projectile and a target
 34 //  excite the projectile and target               35 //  excite the projectile and target
 35 // -------------------------------------------     36 // ------------------------------------------------------------
 36                                                    37 
 37 #include "G4SingleDiffractiveExcitation.hh"    <<  38 
 38 #include "globals.hh"                              39 #include "globals.hh"
 39 #include "G4PhysicalConstants.hh"              << 
 40 #include "G4SystemOfUnits.hh"                  << 
 41 #include "Randomize.hh"                            40 #include "Randomize.hh"
                                                   >>  41 
                                                   >>  42 #include "G4SingleDiffractiveExcitation.hh"
 42 #include "G4LorentzRotation.hh"                    43 #include "G4LorentzRotation.hh"
 43 #include "G4ThreeVector.hh"                        44 #include "G4ThreeVector.hh"
 44 #include "G4ParticleDefinition.hh"                 45 #include "G4ParticleDefinition.hh"
 45 #include "G4VSplitableHadron.hh"                   46 #include "G4VSplitableHadron.hh"
 46 #include "G4ExcitedString.hh"                      47 #include "G4ExcitedString.hh"
                                                   >>  48 //#include "G4ios.hh"
 47                                                    49 
 48 #include "G4Log.hh"                            <<  50 G4SingleDiffractiveExcitation::G4SingleDiffractiveExcitation(G4double sigmaPt, G4double minextraMass,G4double x0mass)
 49 #include "G4Pow.hh"                            <<  51 :
                                                   >>  52 widthOfPtSquare(-2*sqr(sigmaPt)) , minExtraMass(minextraMass),
                                                   >>  53 minmass(x0mass)
                                                   >>  54 {
                                                   >>  55 }
 50                                                    56 
 51 //#define debugSingleDiffraction               <<  57 G4bool G4SingleDiffractiveExcitation::
                                                   >>  58   ExciteParticipants(G4VSplitableHadron *projectile, G4VSplitableHadron *target) const
                                                   >>  59 {
 52                                                    60 
 53 G4SingleDiffractiveExcitation::G4SingleDiffrac <<  61      G4LorentzVector Pprojectile=projectile->Get4Momentum();
                                                   >>  62      G4double Mprojectile2=sqr(projectile->GetDefinition()->GetPDGMass() + minExtraMass);
 54                                                    63 
 55 G4SingleDiffractiveExcitation::~G4SingleDiffra <<  64        G4LorentzVector Ptarget=target->Get4Momentum();
                                                   >>  65        G4double Mtarget2=sqr(target->GetDefinition()->GetPDGMass() + minExtraMass);
                                                   >>  66 //       G4cout << "E proj, target :" << Pprojectile.e() << ", " <<
                                                   >>  67 //              Ptarget.e() << G4endl;
                                                   >>  68 
                                                   >>  69      G4bool KeepProjectile= G4UniformRand() > 0.5;
                                                   >>  70 
                                                   >>  71 //     reset the min.mass of the non diffractive particle to its value, ( minus a bit for rounding...)     
                                                   >>  72      if ( KeepProjectile ) 
                                                   >>  73      {
                                                   >>  74 //      cout << " Projectile fix" << G4endl;
                                                   >>  75       Mprojectile2 = sqr(projectile->GetDefinition()->GetPDGMass() * (1-perCent) ); 
                                                   >>  76      } else {
                                                   >>  77 //      cout << " Target fix" << G4endl;
                                                   >>  78       Mtarget2=sqr(target->GetDefinition()->GetPDGMass() * (1-perCent) );
                                                   >>  79      }
                                                   >>  80 
                                                   >>  81 // Transform momenta to cms and then rotate parallel to z axis;
                                                   >>  82 
                                                   >>  83      G4LorentzVector Psum;
                                                   >>  84      Psum=Pprojectile+Ptarget;
                                                   >>  85 
                                                   >>  86      G4LorentzRotation toCms(-1*Psum.boostVector());
                                                   >>  87 
                                                   >>  88      G4LorentzVector Ptmp=toCms*Pprojectile;
                                                   >>  89 
                                                   >>  90      if ( Ptmp.pz() <= 0. )
                                                   >>  91      {
                                                   >>  92      // "String" moving backwards in  CMS, abort collision !!
                                                   >>  93 //         G4cout << " abort Collision!! " << G4endl;
                                                   >>  94        return false; 
                                                   >>  95      }
                                                   >>  96            
                                                   >>  97      toCms.rotateZ(-1*Ptmp.phi());
                                                   >>  98      toCms.rotateY(-1*Ptmp.theta());
 56                                                    99 
 57 G4bool G4SingleDiffractiveExcitation::         << 100 //     G4cout << "Pprojectile  be4 boost " << Pprojectile << G4endl;
 58 ExciteParticipants( G4VSplitableHadron *projec << 101 //     G4cout << "Ptarget be4 boost : " << Ptarget << G4endl;
 59                     G4bool ProjectileDiffracti << 
 60 {                                              << 
 61   #ifdef debugSingleDiffraction                << 
 62     G4cout<<G4endl<<"G4SingleDiffractiveExcita << 
 63   #endif                                       << 
 64                                                << 
 65   G4LorentzVector Pprojectile=projectile->Get4 << 
 66   G4double Mprojectile =    projectile->GetDef << 
 67   G4double Mprojectile2=sqr(projectile->GetDef << 
 68                                                << 
 69   G4LorentzVector Ptarget=target->Get4Momentum << 
 70   G4double Mtarget =    target->GetDefinition( << 
 71   G4double Mtarget2=sqr(target->GetDefinition( << 
 72                                                << 
 73   #ifdef debugSingleDiffraction                << 
 74     G4cout<<"Proj Targ "<<projectile->GetDefin << 
 75     G4cout<<"Pr Tr 4-Mom "<<Pprojectile<<" "<< << 
 76           <<"            "<<Ptarget    <<" "<< << 
 77   #endif                                       << 
 78                                                << 
 79   G4LorentzVector Psum=Pprojectile+Ptarget;    << 
 80   G4double SqrtS=Psum.mag();                   << 
 81   G4double S    =Psum.mag2();                  << 
 82                                                << 
 83   #ifdef debugSingleDiffraction                << 
 84     G4cout<<"SqrtS-Mprojectile-Mtarget "<<Sqrt << 
 85           <<" "<<SqrtS-Mprojectile-Mtarget<<G4 << 
 86   #endif                                       << 
 87   if (SqrtS-Mprojectile-Mtarget <= 250.0*MeV)  << 
 88     #ifdef debugSingleDiffraction              << 
 89     G4cerr<<"Projectile: "<<projectile->GetDef << 
 90           <<Pprojectile<<" "<<Pprojectile.mag( << 
 91     G4cerr<<"Target:     "<<target->GetDefinit << 
 92           <<Ptarget<<" "<<Ptarget.mag()<<G4end << 
 93     G4cerr<<"sqrt(S) = "<<SqrtS<<" Mp + Mt = " << 
 94     #endif                                     << 
 95     return true;                               << 
 96   }                                            << 
 97                                                << 
 98   G4LorentzRotation toCms(-1*Psum.boostVector( << 
 99                                                << 
100   G4LorentzVector Ptmp=toCms*Pprojectile;      << 
101                                                << 
102   if ( Ptmp.pz() <= 0. )                       << 
103   {                                            << 
104     // "String" moving backwards in  CMS, abor << 
105     //         G4cout << " abort Collision!! " << 
106     return false;                              << 
107   }                                            << 
108                                                << 
109   toCms.rotateZ(-1*Ptmp.phi());                << 
110   toCms.rotateY(-1*Ptmp.theta());              << 
111                                                << 
112   G4LorentzRotation toLab(toCms.inverse());    << 
113                                                << 
114   Pprojectile.transform(toCms);                << 
115   Ptarget.transform(toCms);                    << 
116   #ifdef debugSingleDiffraction                << 
117     G4cout << "Pprojectile  in CMS " << Pproje << 
118     G4cout << "Ptarget      in CMS " << Ptarge << 
119   #endif                                       << 
120   G4double maxPtSquare=sqr(Ptarget.pz());      << 
121                                                << 
122   G4double ProjectileMinDiffrMass(0.), TargetM << 
123   G4double AveragePt2(0.);                     << 
124   G4int absPDGcode=std::abs(projectile->GetDef << 
125                                                << 
126   if ( ProjectileDiffraction ) {               << 
127     if ( absPDGcode > 1000 )                   << 
128     {                                          << 
129       if ( absPDGcode > 4000 && absPDGcode < 6 << 
130       {                                        << 
131         ProjectileMinDiffrMass = projectile->G << 
132         AveragePt2 = 0.3;                      << 
133       }                                        << 
134       else                                     << 
135       {                                        << 
136         ProjectileMinDiffrMass = 1.16;         << 
137         AveragePt2 = 0.3;                      << 
138       }                                        << 
139     }                                          << 
140     else if( absPDGcode == 211 || absPDGcode = << 
141     {                                          << 
142       ProjectileMinDiffrMass = 1.0;            << 
143       AveragePt2 = 0.3;                        << 
144     }                                          << 
145     else if( absPDGcode == 321 || absPDGcode = << 
146     {                                          << 
147       ProjectileMinDiffrMass = 1.1;            << 
148       AveragePt2 = 0.3;                        << 
149     }                                          << 
150     else if( absPDGcode == 22)                 << 
151     {                                          << 
152       ProjectileMinDiffrMass = 0.25;           << 
153       AveragePt2 = 0.36;                       << 
154     }                                          << 
155     else if( absPDGcode > 400 && absPDGcode <  << 
156     {                                          << 
157       ProjectileMinDiffrMass = projectile->Get << 
158       AveragePt2 = 0.3;                        << 
159     }                                          << 
160     else                                       << 
161     {                                          << 
162       ProjectileMinDiffrMass = 1.1;            << 
163       AveragePt2 = 0.3;                        << 
164     };                                         << 
165                                                << 
166     ProjectileMinDiffrMass = ProjectileMinDiff << 
167     Mprojectile2=sqr(ProjectileMinDiffrMass);  << 
168   }                                            << 
169   else                                         << 
170   {                                            << 
171     TargetMinDiffrMass = 1.16*GeV;             << 
172     Mtarget2 = sqr( TargetMinDiffrMass) ;      << 
173     AveragePt2 = 0.3;                          << 
174   }   // end of if ( ProjectileDiffraction )   << 
175                                                << 
176   AveragePt2 = AveragePt2 * GeV*GeV;           << 
177                                                << 
178   G4double Pt2, PZcms, PZcms2;                 << 
179   G4double ProjMassT2, ProjMassT;              << 
180   G4double TargMassT2, TargMassT;              << 
181   G4double PMinusMin, PMinusMax;               << 
182   G4double TPlusMin, TPlusMax;                 << 
183   G4double PMinusNew, PPlusNew, TPlusNew, TMin << 
184                                                << 
185   G4LorentzVector Qmomentum;                   << 
186   G4double Qminus, Qplus;                      << 
187                                                << 
188   G4int whilecount=0;                          << 
189   do {                                         << 
190     whilecount++;                              << 
191                                                << 
192     if (whilecount > 1000 )                    << 
193     {                                          << 
194       Qmomentum=G4LorentzVector(0.,0.,0.,0.);  << 
195       return false;     //  Ignore this intera << 
196     }                                          << 
197                                                << 
198     //  Generate pt                            << 
199     Qmomentum=G4LorentzVector(GaussianPt(Avera << 
200                                                << 
201     Pt2 = G4ThreeVector( Qmomentum.vect() ).ma << 
202                                                << 
203     ProjMassT2 = Mprojectile2 + Pt2;           << 
204     ProjMassT = std::sqrt( ProjMassT2 );       << 
205     TargMassT2 = Mtarget2 + Pt2;               << 
206     TargMassT = std::sqrt( TargMassT2 );       << 
207                                                << 
208     #ifdef debugSingleDiffraction              << 
209       G4cout<<whilecount<<" "<<Pt2<<" "<<ProjM << 
210     #endif                                     << 
211     if ( SqrtS < ProjMassT + TargMassT ) conti << 
212                                                << 
213     PZcms2 = ( S*S + ProjMassT2*ProjMassT2 + T << 
214               - 2.0*S*ProjMassT2 - 2.0*S*TargM << 
215                                                << 
216     if ( PZcms2 < 0 ) continue;                << 
217                                                << 
218     PZcms = std::sqrt( PZcms2 );               << 
219                                                << 
220     if ( ProjectileDiffraction )               << 
221     {       // The projectile will fragment, t << 
222       PMinusMin = std::sqrt( ProjMassT2 + PZcm << 
223       PMinusMax = SqrtS - TargMassT;           << 
224                                                << 
225       PMinusNew = ChooseX( PMinusMin, PMinusMa << 
226       TMinusNew = SqrtS - PMinusNew;           << 
227                                                << 
228       Qminus = Ptarget.minus() - TMinusNew;    << 
229       TPlusNew = TargMassT2 / TMinusNew;       << 
230       Qplus = Ptarget.plus() - TPlusNew;       << 
231                                                << 
232     } else {  // The target will fragment, the << 
233       TPlusMin = std::sqrt( TargMassT2 + PZcms << 
234       TPlusMax = SqrtS - ProjMassT;            << 
235                                                   102   
236       TPlusNew = ChooseX( TPlusMin, TPlusMax ) << 
237       PPlusNew = SqrtS - TPlusNew;             << 
238                                                   103 
239       Qplus = PPlusNew - Pprojectile.plus();   << 
240       PMinusNew = ProjMassT2 / PPlusNew;       << 
241       Qminus = PMinusNew - Pprojectile.minus() << 
242     }                                          << 
243                                                << 
244     Qmomentum.setPz( (Qplus - Qminus)/2 );     << 
245     Qmomentum.setE(  (Qplus + Qminus)/2 );     << 
246                                                << 
247     #ifdef debugSingleDiffraction              << 
248       G4cout<<ProjectileDiffraction<<" "<<( Pp << 
249       G4cout<<!ProjectileDiffraction<<" "<<( P << 
250     #endif                                     << 
251                                                << 
252   } while ( ( ProjectileDiffraction&&( Pprojec << 
253             (!ProjectileDiffraction&&( Ptarget << 
254     // Repeat the sampling because there was n << 
255                                                << 
256   Pprojectile += Qmomentum;                    << 
257                                                << 
258   Ptarget     -= Qmomentum;                    << 
259                                                << 
260   // Transform back and update SplitableHadron << 
261   Pprojectile.transform(toLab);                << 
262   Ptarget.transform(toLab);                    << 
263                                                << 
264   #ifdef debugSingleDiffraction                << 
265     G4cout << "Pprojectile  in Lab. " << Pproj << 
266     G4cout << "Ptarget      in Lab. " << Ptarg << 
267     G4cout << "G4SingleDiffractiveExcitation-  << 
268     G4cout << "G4SingleDiffractiveExcitation-  << 
269   #endif                                       << 
270                                                   104 
271   target->Set4Momentum(Ptarget);               << 105      G4LorentzRotation toLab(toCms.inverse());
272   projectile->Set4Momentum(Pprojectile);       << 106 
                                                   >> 107      Pprojectile.transform(toCms);
                                                   >> 108      Ptarget.transform(toCms);
273                                                   109 
274   return true;                                 << 110      G4LorentzVector Qmomentum;
                                                   >> 111      G4int whilecount=0;
                                                   >> 112      do {
                                                   >> 113 //  Generate pt   
                                                   >> 114 
                                                   >> 115          G4double maxPtSquare=sqr(Ptarget.pz());
                                                   >> 116          if (whilecount++ >= 500 && (whilecount%100)==0) 
                                                   >> 117 //       G4cout << "G4SingleDiffractiveExcitation::ExciteParticipants possibly looping"
                                                   >> 118 //       << ", loop count/ maxPtSquare : " 
                                                   >> 119 //             << whilecount << " / " << maxPtSquare << G4endl;
                                                   >> 120                if (whilecount > 1000 ) 
                                                   >> 121                {
                                                   >> 122                Qmomentum=G4LorentzVector(0.,0.,0.,0.);
                                                   >> 123 //       G4cout << "G4SingleDiffractiveExcitation::ExciteParticipants: Aborting loop!" << G4endl;
                                                   >> 124        return false;    //  Ignore this interaction 
                                                   >> 125                }
                                                   >> 126          Qmomentum=G4LorentzVector(GaussianPt(widthOfPtSquare,maxPtSquare),0);
                                                   >> 127 
                                                   >> 128 
                                                   >> 129 //  Momentum transfer
                                                   >> 130          G4double Xmin = minmass / ( Pprojectile.e() + Ptarget.e() );
                                                   >> 131          G4double Xmax=1.;
                                                   >> 132          G4double Xplus =ChooseX(Xmin,Xmax);
                                                   >> 133          G4double Xminus=ChooseX(Xmin,Xmax);
                                                   >> 134          
                                                   >> 135          G4double pt2=G4ThreeVector(Qmomentum.vect()).mag2();
                                                   >> 136          G4double Qplus =-1 * pt2 / Xminus/Ptarget.minus();
                                                   >> 137          G4double Qminus=     pt2 / Xplus /Pprojectile.plus();
                                                   >> 138          
                                                   >> 139          if ( KeepProjectile )
                                                   >> 140          { 
                                                   >> 141               Qminus = (sqr(projectile->GetDefinition()->GetPDGMass()) + pt2 ) 
                                                   >> 142                 / (Pprojectile.plus() + Qplus ) 
                                                   >> 143                       -  Pprojectile.minus();
                                                   >> 144           } else
                                                   >> 145     {
                                                   >> 146        Qplus = Ptarget.plus()
                                                   >> 147               - (sqr(target->GetDefinition()->GetPDGMass()) + pt2 ) 
                                                   >> 148          / (Ptarget.minus() - Qminus );   
                                                   >> 149     }     
                                                   >> 150   
                                                   >> 151          Qmomentum.setPz( (Qplus-Qminus)/2 );
                                                   >> 152          Qmomentum.setE(  (Qplus+Qminus)/2 );
                                                   >> 153 
                                                   >> 154 //   G4cout << "Qplus / Qminus " << Qplus << " / " << Qminus<<G4endl;
                                                   >> 155 //   G4cout << "pt2 " << pt2 << G4endl;
                                                   >> 156 //   G4cout << "Qmomentum " << Qmomentum << G4endl;
                                                   >> 157 //   G4cout << " Masses (P/T) : " << (Pprojectile+Qmomentum).mag() <<
                                                   >> 158 //         " / " << (Ptarget-Qmomentum).mag() << G4endl;
                                                   >> 159 
                                                   >> 160      } while (  (Ptarget-Qmomentum).mag2() <= Mtarget2 
                                                   >> 161            || (Pprojectile+Qmomentum).mag2() <= Mprojectile2
                                                   >> 162                || (Ptarget-Qmomentum).e() < 0. 
                                                   >> 163          || (Pprojectile+Qmomentum).e() < 0. );
                                                   >> 164 
                                                   >> 165 
                                                   >> 166 //     G4double Ecms=Pprojectile.e() + Ptarget.e();
                                                   >> 167      
                                                   >> 168      Pprojectile += Qmomentum;
                                                   >> 169 
                                                   >> 170      Ptarget     -= Qmomentum;
                                                   >> 171      
                                                   >> 172 //     G4cout << "Pprojectile.e()  : " << Pprojectile.e() << G4endl;
                                                   >> 173 //     G4cout << "Ptarget.e()      : " << Ptarget.e() << G4endl;
                                                   >> 174 
                                                   >> 175 //     G4cout << "end event_______________________________________________"<<G4endl;
                                                   >> 176 //     
                                                   >> 177 
                                                   >> 178 
                                                   >> 179 //     G4cout << "Pprojectile with Q : " << Pprojectile << G4endl;
                                                   >> 180 //     G4cout << "Ptarget with Q : " << Ptarget << G4endl;
                                                   >> 181 //     G4cout << "Projectile back: " << toLab * Pprojectile << G4endl;
                                                   >> 182 //     G4cout << "Target back: " << toLab * Ptarget << G4endl;
                                                   >> 183 
                                                   >> 184 // Transform back and update SplitableHadron Participant.
                                                   >> 185      Pprojectile.transform(toLab);
                                                   >> 186      Ptarget.transform(toLab);
                                                   >> 187 
                                                   >> 188 //     G4cout << "G4SingleDiffractiveExcitation- Target mass      " <<  Ptarget.mag() << G4endl;
                                                   >> 189 //     G4cout << "G4SingleDiffractiveExcitation- Projectile mass  " <<  Pprojectile.mag() << G4endl;
                                                   >> 190            
                                                   >> 191      target->Set4Momentum(Ptarget);
                                                   >> 192      projectile->Set4Momentum(Pprojectile);
                                                   >> 193   
                                                   >> 194   
                                                   >> 195   return true;
275 }                                                 196 }
276                                                   197 
                                                   >> 198 
                                                   >> 199 
                                                   >> 200 
277 // --------- private methods -----------------    201 // --------- private methods ----------------------
278                                                   202 
279 G4double G4SingleDiffractiveExcitation::Choose    203 G4double G4SingleDiffractiveExcitation::ChooseX(G4double Xmin, G4double Xmax) const
280 {                                                 204 {
281   // choose an x between Xmin and Xmax with P( << 205 // choose an x between Xmin and Xmax with P(x) ~ 1/x
282   G4double range=Xmax-Xmin;                    << 
283                                                   206 
284   if ( Xmin <= 0. || range <=0. )              << 207 //  to be improved...
285   {                                            << 
286     G4cout << " Xmin, range : " << Xmin << " , << 
287     throw G4HadronicException(__FILE__, __LINE << 
288   }                                            << 
289                                                << 
290   G4double x = Xmin*G4Pow::GetInstance()->powA << 
291   // G4double x = 1.0/sqr(1.0/std::sqrt(Xmin)  << 
292   return x;                                    << 
293 }                                              << 
294                                                   208 
                                                   >> 209   G4double range=Xmax-Xmin;
                                                   >> 210   
                                                   >> 211   if ( Xmin <= 0. || range <=0. ) 
                                                   >> 212   {
                                                   >> 213     G4cout << " Xmin, range : " << Xmin << " , " << range << G4endl;
                                                   >> 214     throw G4HadronicException(__FILE__, __LINE__, "G4SingleDiffractiveExcitation::ChooseX : Invalid arguments ");
                                                   >> 215   }
                                                   >> 216 
                                                   >> 217   G4double x;
                                                   >> 218   do {
                                                   >> 219       x=Xmin + G4UniformRand() * range;
                                                   >> 220   }  while ( Xmin/x < G4UniformRand() );
                                                   >> 221 
                                                   >> 222 //  cout << "DiffractiveX "<<x<<G4endl;
                                                   >> 223   return x;
                                                   >> 224 }
295                                                   225 
296 G4ThreeVector G4SingleDiffractiveExcitation::G    226 G4ThreeVector G4SingleDiffractiveExcitation::GaussianPt(G4double widthSquare, G4double maxPtSquare) const
297 {            //  @@ this method is used in FTF    227 {            //  @@ this method is used in FTFModel as well. Should go somewhere common!
                                                   >> 228   
                                                   >> 229   G4double pt2;
                                                   >> 230 
                                                   >> 231   do {
                                                   >> 232       pt2=widthSquare * std::log( G4UniformRand() );
                                                   >> 233   } while ( pt2 > maxPtSquare);
                                                   >> 234   
                                                   >> 235   pt2=std::sqrt(pt2);
                                                   >> 236   
                                                   >> 237   G4double phi=G4UniformRand() * twopi;
                                                   >> 238   
                                                   >> 239   return G4ThreeVector (pt2*std::cos(phi), pt2*std::sin(phi), 0.);    
                                                   >> 240 }
                                                   >> 241 
                                                   >> 242 G4SingleDiffractiveExcitation::G4SingleDiffractiveExcitation(const G4SingleDiffractiveExcitation &)
                                                   >> 243 : G4QGSDiffractiveExcitation(),
                                                   >> 244 widthOfPtSquare(0) , minExtraMass(0),
                                                   >> 245 minmass(0)
                                                   >> 246 {
                                                   >> 247   throw G4HadronicException(__FILE__, __LINE__, "G4SingleDiffractiveExcitation copy contructor not meant to be called");
                                                   >> 248 }
                                                   >> 249 
                                                   >> 250 
                                                   >> 251 G4SingleDiffractiveExcitation::~G4SingleDiffractiveExcitation()
                                                   >> 252 {
                                                   >> 253 }
298                                                   254 
299   G4double pt2;                                << 
300                                                   255 
301   const G4int maxNumberOfLoops = 1000;         << 256 const G4SingleDiffractiveExcitation & G4SingleDiffractiveExcitation::operator=(const G4SingleDiffractiveExcitation &)
302   G4int loopCounter = 0;                       << 257 {
303   do {                                         << 258   throw G4HadronicException(__FILE__, __LINE__, "G4SingleDiffractiveExcitation = operator meant to be called");
304     pt2=-widthSquare * G4Log( G4UniformRand()  << 259   return *this;
305   } while ( ( pt2 > maxPtSquare) && ++loopCoun << 260 }
306   if ( loopCounter >= maxNumberOfLoops ) {     << 
307     pt2 = 0.99*maxPtSquare;  // Just an accept << 
308   }                                            << 
309                                                   261 
310   pt2=std::sqrt(pt2);                          << 
311                                                   262 
312   G4double phi=G4UniformRand() * twopi;        << 263 int G4SingleDiffractiveExcitation::operator==(const G4SingleDiffractiveExcitation &) const
                                                   >> 264 {
                                                   >> 265   throw G4HadronicException(__FILE__, __LINE__, "G4SingleDiffractiveExcitation == operator meant to be called");
                                                   >> 266   return false;
                                                   >> 267 }
313                                                   268 
314   return G4ThreeVector (pt2*std::cos(phi), pt2 << 269 int G4SingleDiffractiveExcitation::operator!=(const G4SingleDiffractiveExcitation &) const
                                                   >> 270 {
                                                   >> 271   throw G4HadronicException(__FILE__, __LINE__, "G4SingleDiffractiveExcitation != operator meant to be called");
                                                   >> 272   return true;
315 }                                                 273 }
                                                   >> 274 
                                                   >> 275 
                                                   >> 276 
                                                   >> 277 
316                                                   278 
317                                                   279