1 /**************************************************************************
2 * Copyright(c) 1998-2007, ALICE Experiment at CERN, All rights reserved. *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
7 * Permission to use, copy, modify and distribute this software and its *
8 * documentation strictly for non-commercial purposes is hereby granted *
9 * without fee, provided that the above copyright notice appears in all *
10 * copies and that both the copyright notice and this permission notice *
11 * appear in the supporting documentation. The authors make no claims *
12 * about the suitability of this software for any purpose. It is *
13 * provided "as is" without express or implied warranty. *
14 **************************************************************************/
17 // Generator for muons according to kinematic parametrizations at ALICE
18 // (not at the surface).
19 // Origin: andrea.dainese@lnl.infn.it
21 #include <TParticle.h>
25 #include "AliESDtrack.h"
26 #include "AliESDVertex.h"
27 #include "AliGenCosmicsParam.h"
29 ClassImp(AliGenCosmicsParam)
31 //-----------------------------------------------------------------------------
32 AliGenCosmicsParam::AliGenCosmicsParam():
37 fMaxAngleWRTVertical(-99.),
49 fBottomScintillator(kFALSE)
52 // Default constructor
54 SetNumberParticles(1);
56 //-----------------------------------------------------------------------------
57 void AliGenCosmicsParam::Generate()
67 Double_t ptot=0,pt=0,angleWRTVertical=0;
68 Bool_t okMom=kFALSE,okAngle=kFALSE;
70 Float_t rtrigger=1000.0,ztrigger=600.0;
71 if(fTPC) { rtrigger=250.0; ztrigger=250.0; }
72 if(fITS) { rtrigger=50.0; ztrigger=50.0; }
73 if(fSPDinner) { rtrigger=3.5; ztrigger=14.0; }
74 if(fSPDouter) { rtrigger=6.5; ztrigger=14.0; }
75 if(fSDDinner) { rtrigger=14.0; ztrigger=21.0; }
76 if(fSDDouter) { rtrigger=23.0; ztrigger=29.0; }
77 if(fSSDinner) { rtrigger=37.0; ztrigger=42.0; }
78 if(fSSDouter) { rtrigger=42.0; ztrigger=48.0; }
82 Float_t muMinusFraction = 4./9.; // mu+/mu- = 1.25
88 while (npart<fNpart) {
90 if(gRandom->Rndm()<muMinusFraction) {
96 if(fParamACORDE) { // extracted from AliGenACORDE events
97 // sample total momentum only once (to speed up)
98 TF1 *dNdpACORDE = new TF1("dNdpACORDE","x/(1.+(x/12.8)*(x/12.8))^1.96",fPMin,fPMax);
99 ptot = (Double_t)dNdpACORDE->GetRandom();
107 origin[0] = (fYOrigin*TMath::Tan(fMaxAngleWRTVertical)+rtrigger)*(-1.+2.*gRandom->Rndm());
108 origin[1] = fYOrigin;
109 origin[2] = (fYOrigin*TMath::Tan(fMaxAngleWRTVertical)+ztrigger)*(-1.+2.*gRandom->Rndm());
113 okMom=kFALSE; okAngle=kFALSE;
115 if(fParamMI) { // parametrization by M.Ivanov of LEP cosmics data
116 Float_t pref = 1. + gRandom->Exp(30.);
118 p[0] = gRandom->Gaus(0.0,0.2)*pref;
119 p[2] = gRandom->Gaus(0.0,0.2)*pref;
120 if(gRandom->Rndm()>0.9) {
121 p[0] = gRandom->Gaus(0.0,0.4)*pref;
122 p[2] = gRandom->Gaus(0.0,0.4)*pref;
124 ptot=TMath::Sqrt(p[0]*p[0]+p[1]*p[1]+p[2]*p[2]);
125 pt=TMath::Sqrt(p[0]*p[0]+p[1]*p[1]);
126 } else if(fParamACORDE) { // extracted from AliGenACORDE events
129 theta = gRandom->Gaus(0.5*TMath::Pi(),0.42);
130 if(TMath::Abs(theta-0.5*TMath::Pi())<fMaxAngleWRTVertical) break;
133 phi = gRandom->Gaus(-0.5*TMath::Pi(),0.42);
134 if(TMath::Abs(phi+0.5*TMath::Pi())<fMaxAngleWRTVertical) break;
136 pt = ptot*TMath::Sin(theta);
137 p[0] = pt*TMath::Cos(phi);
138 p[1] = pt*TMath::Sin(phi);
139 p[2] = ptot*TMath::Cos(theta);
141 AliFatal("Parametrization not set: use SetParamMI or SetParamACORDE");
145 // check kinematic cuts
146 if(TestBit(kMomentumRange)) {
147 if(ptot>fPMin && ptot<fPMax) okMom=kTRUE;
152 angleWRTVertical=TMath::ACos(TMath::Abs(p[1])/ptot); // acos(|py|/ptot)
153 if(angleWRTVertical<fMaxAngleWRTVertical) okAngle=kTRUE;
155 if(okAngle&&okMom) break;
158 // acceptance trigger
159 if(IntersectCylinder(rtrigger,ztrigger,ipart,origin,p)) {
160 if(fACORDE && !fBottomScintillator) {
161 if(IntersectACORDE(ipart,origin,p)) break;
162 } else if(!fACORDE && fBottomScintillator) {
163 if(IntersectBottomScintillator(ipart,origin,p)) break;
164 } else if(fACORDE && fBottomScintillator) {
165 if(IntersectACORDE(ipart,origin,p) &&
166 IntersectBottomScintillator(ipart,origin,p)) break;
167 } else { // !fACORDE && !fBottomScintillator
174 Float_t polarization[3]= {0,0,0};
175 PushTrack(fTrackIt,-1,ipart,p,origin,polarization,0,kPPrimary,nt);
177 //printf("TRIALS %d\n",trials);
182 //-----------------------------------------------------------------------------
183 void AliGenCosmicsParam::Init()
186 // Initialisation, check consistency of selected ranges
188 if(TestBit(kPtRange))
189 AliFatal("You cannot set the pt range for this generator! Only momentum range");
192 if(TestBit(kMomentumRange))
193 AliWarning("Minimum momentum cannot be < 8 GeV/c");
195 if(fMaxAngleWRTVertical<0.)
196 AliFatal("You must use SetMaxAngleWRTVertical() instead of SetThetaRange(), SetPhiRange()");
198 printf("************ AliGenCosmicsParam ****************\n");
199 printf("***** Muons generated at Y = %f cm\n",fYOrigin);
200 printf("************************************************\n");
204 //-----------------------------------------------------------------------------
205 Bool_t AliGenCosmicsParam::IntersectCylinder(Float_t r,Float_t z,Int_t pdg,
206 Float_t o[3],Float_t p[3]) const
209 // Intersection between muon and cylinder [-z,+z] with radius r
212 Float_t en = TMath::Sqrt(0.105*0.105+p[0]*p[0]+p[1]*p[1]+p[2]*p[2]);
213 TParticle part(pdg,0,0,0,0,0,p[0],p[1],p[2],en,o[0],o[1],o[2],0);
214 AliESDtrack track(&part);
215 Double_t pos[3]={0.,0.,0.},sigma[3]={0.,0.,0.};
216 AliESDVertex origin(pos,sigma);
218 track.RelateToVertex(&origin,fBkG,10000.);
220 Float_t d0z0[2],covd0z0[3];
221 track.GetImpactParameters(d0z0,covd0z0);
224 if(TMath::Abs(d0z0[0])>r) return kFALSE;
226 if(TMath::Abs(d0z0[1])>z) return kFALSE;
229 if(TMath::Abs(fB)<0.01) { // NO FIELD
230 Float_t drphi = TMath::Abs(o[1]-p[1]/p[0]*o[0])/
231 TMath::Sqrt(p[1]*p[1]/p[0]/p[0]+1.);
232 if(drphi>r) return kFALSE;
233 Float_t dz = o[2]-p[2]/p[0]*o[0]+p[2]/p[0]*
234 (p[1]*p[1]/p[0]/p[0]*o[0]-p[1]/p[0]*o[1])/(1.+p[1]*p[1]/p[0]/p[0]);
235 if(TMath::Abs(dz)>z) return kFALSE;
241 //-----------------------------------------------------------------------------
242 Bool_t AliGenCosmicsParam::IntersectACORDE(Int_t pdg,
243 Float_t o[3],Float_t p[3]) const
246 // Intersection between muon and ACORDE (very rough)
249 Float_t en = TMath::Sqrt(0.105*0.105+p[0]*p[0]+p[1]*p[1]+p[2]*p[2]);
250 TParticle part(pdg,0,0,0,0,0,-p[0],-p[1],-p[2],en,o[0],o[1],o[2],0);
251 AliESDtrack track(&part);
253 Float_t rACORDE=800.0,xACORDE=750.0/*250.0*/,zACORDE=500.0;
254 if(fACORDE4ITS) { xACORDE=100.0; zACORDE=100.0; }
256 Double_t planepoint[3]={0.,rACORDE,0.};
257 Double_t planenorm[3]={0.,1.,0.};
259 if(!track.Intersect(planepoint,planenorm,fBkG)) return kFALSE;
261 Double_t xyz[3]={planepoint[0],planepoint[1],planepoint[2]};
262 //printf("XYZ = %f %f %f\n",xyz[0],xyz[1],xyz[2]);
265 if(TMath::Abs(xyz[0]) > xACORDE) return kFALSE;
267 if(TMath::Abs(xyz[2]) > zACORDE) return kFALSE;
271 //-----------------------------------------------------------------------------
272 Bool_t AliGenCosmicsParam::IntersectBottomScintillator(Int_t pdg,
273 Float_t o[3],Float_t p[3]) const
276 // Intersection between muon and ACORDE (very rough)
279 Float_t en = TMath::Sqrt(0.105*0.105+p[0]*p[0]+p[1]*p[1]+p[2]*p[2]);
280 TParticle part(pdg,0,0,0,0,0,-p[0],-p[1],-p[2],en,o[0],o[1],o[2],0);
281 AliESDtrack track(&part);
283 Double_t xSc=40.,ySc=-350.,zSc=40.;
285 Double_t planepoint[3]={0.,ySc,0.};
286 Double_t planenorm[3]={0.,1.,0.};
288 if(!track.Intersect(planepoint,planenorm,fBkG)) return kFALSE;
290 Double_t xyz[3]={planepoint[0],planepoint[1],planepoint[2]};
291 //printf("XYZ = %f %f %f\n",xyz[0],xyz[1],xyz[2]);
294 if(TMath::Abs(xyz[0]) > xSc) return kFALSE;
296 if(TMath::Abs(xyz[2]) > zSc) return kFALSE;
300 //-----------------------------------------------------------------------------