+ // Applying beam divergence and crossing angle
+ //
+ Double_t pmod = TMath::Sqrt(pLab[0]*pLab[0]+pLab[1]*pLab[1]+pLab[2]*pLab[2]);
+
+ Double_t tetdiv = 0.;
+ Double_t fidiv = 0.;
+ if(iwhat==1){
+ tetdiv = fBeamCrossingAngle;
+ fidiv = k2PI/4.;
+ }
+ else if(iwhat==2){
+ tetdiv = fBeamDivEvent;
+ fidiv = (gRandom->Rndm())*k2PI;
+ }
+
+ Double_t tetpart = TMath::ATan2(TMath::Sqrt(pLab[0]*pLab[0]+pLab[1]*pLab[1]), pLab[2]);
+ Double_t fipart=0.;
+ if(TMath::Abs(pLab[1])>0. || TMath::Abs(pLab[0])>0.) fipart = TMath::ATan2(pLab[1], pLab[0]);
+ if(fipart<0.) {fipart = fipart+k2PI;}
+ tetdiv = tetdiv*kRaddeg;
+ fidiv = fidiv*kRaddeg;
+ tetpart = tetpart*kRaddeg;
+ fipart = fipart*kRaddeg;
+
+ Double_t angleSum[2]={0., 0.};
+ AddAngle(tetpart,fipart,tetdiv,fidiv,angleSum);
+
+ Double_t tetsum = angleSum[0];
+ Double_t fisum = angleSum[1];
+ //printf("tetpart %f fipart %f tetdiv %f fidiv %f angleSum %f %f\n",tetpart,fipart,tetdiv,fidiv,angleSum[0],angleSum[1]);
+ tetsum = tetsum*kDegrad;
+ fisum = fisum*kDegrad;
+
+ pLab[0] = pmod*TMath::Sin(tetsum)*TMath::Cos(fisum);
+ pLab[1] = pmod*TMath::Sin(tetsum)*TMath::Sin(fisum);
+ pLab[2] = pmod*TMath::Cos(tetsum);
+ if(fDebug==1){
+ if(iwhat==1) printf(" Beam crossing angle %f mrad ", fBeamCrossingAngle*1000.);
+ else if(iwhat==2) printf(" Beam divergence %f mrad ", fBeamDivEvent*1000.);
+ printf(" p = (%f, %f, %f)\n",pLab[0],pLab[1],pLab[2]);
+ }