1 //Author: Anders Strand Vestbo
2 //Author: Uli Frankenfeld
3 //Last Modified: 06.03.2001
5 //____________________________________
8 // Base track class for L3
12 //14.03.01: Moved fHitNumbers from protected to private.-ASV
13 // Set memory to zero in ctor.
14 // Moved fNHits 2 private. Protected data members not a good idea after all.
15 //19.03.01: Made the method void Set(AliL3Track) virtual.
17 #include "AliL3RootTypes.h"
19 #include "AliL3Logging.h"
20 #include "AliL3Track.h"
25 Float_t AliL3Track::BFACT = 0.0029980;
26 Float_t AliL3Track::bField = 0.2;
27 Double_t AliL3Track::pi=3.14159265358979323846;
29 AliL3Track::AliL3Track()
39 ComesFromMainVertex(false);
51 memset(fHitNumbers,0,174*sizeof(UInt_t));
54 void AliL3Track::Set(AliL3Track *tpt){
56 SetRowRange(tpt->GetFirstRow(),tpt->GetLastRow());
57 SetPhi0(tpt->GetPhi0());
58 SetKappa(tpt->GetKappa());
59 SetNHits(tpt->GetNHits());
61 SetFirstPoint(tpt->GetFirstPointX(),tpt->GetFirstPointY(),tpt->GetFirstPointZ());
63 SetLastPoint(tpt->GetLastPointX(),tpt->GetLastPointY(),tpt->GetLastPointZ());
65 SetPsi(tpt->GetPsi());
66 SetTgl(tpt->GetTgl());
67 SetCharge(tpt->GetCharge());
69 SetHits(tpt->GetNHits(),(UInt_t *)tpt->GetHitNumbers());
72 fPhi0 = track->GetPhi0();
73 fKappa = track->GetKappa();
75 fRowRange[0] = track->GetFirstRow();
76 fRowRange[1] = track->GetLastRow();
77 fQ = track->GetCharge();
78 fFirstPoint[0] = track->GetFirstPointX();
79 fFirstPoint[1] = track->GetFirstPointY();
80 fFirstPoint[2] = track->GetFirstPointZ();
81 fLastPoint[0] = track->GetLastPointX();
82 fLastPoint[1] = track->GetLastPointY();
83 fLastPoint[2] = track->GetLastPointZ();
85 fTanl = track->GetTgl();
86 fPsi = track->GetPsi();
87 fQ = track->GetCharge();
88 fNHits = track->GetNHits();
89 memcpy(fHitNumbers,track->GetHitNumbers(),fNHits*sizeof(UInt_t));
94 AliL3Track::~AliL3Track()
99 Double_t AliL3Track::GetP() const
101 // Returns total momentum.
103 return fabs(GetPt())*sqrt(1. + GetTgl()*GetTgl());
107 Double_t AliL3Track::GetPseudoRapidity() const
109 return 0.5 * log((GetP() + GetPz()) / (GetP() - GetPz()));
112 Double_t AliL3Track::GetEta() const
114 return GetPseudoRapidity();
117 Double_t AliL3Track::GetRapidity() const
119 Double_t m_pi = 0.13957;
120 return 0.5 * log((m_pi + GetPz()) / (m_pi - GetPz()));
123 void AliL3Track::CalculateHelix(){
124 //Calculate Radius, CenterX and Centery from Psi, X0, Y0
127 fRadius = fPt / (BFACT*bField);
128 if(fRadius) fKappa = 1./fRadius;
129 else fRadius = 999999; //just zero
130 Double_t trackPhi0 = fPsi + fQ *0.5 * pi;
132 fCenterX = fFirstPoint[0] - fRadius * cos(trackPhi0);
133 fCenterY = fFirstPoint[1] - fRadius * sin(trackPhi0);
136 Bool_t AliL3Track::CalculateReferencePoint(Double_t angle){
137 // Global coordinate: crossing point with y = ax+ b; a=tan(angle-Pi/2);
139 const Double_t rr=132; //position of referece plane
140 const Double_t xr = cos(angle) *rr;
141 const Double_t yr = sin(angle) *rr;
143 Double_t a = tan(angle-pi/2);
144 Double_t b = yr - a * xr;
146 Double_t pp=(fCenterX+a*fCenterY-a*b)/(1+pow(a,2));
147 Double_t qq=(pow(fCenterX,2)+pow(fCenterY,2)-2*fCenterY*b+pow(b,2)-pow(fRadius,2))/(1+pow(a,2));
149 Double_t racine = pp*pp-qq;
150 if(racine<0) return IsPoint(kFALSE); //no Point
152 Double_t rootRacine = sqrt(racine);
153 Double_t x0 = pp+rootRacine;
154 Double_t x1 = pp-rootRacine;
155 Double_t y0 = a*x0 + b;
156 Double_t y1 = a*x1 + b;
158 Double_t diff0 = sqrt(pow(x0-xr,2)+pow(y0-yr,2));
159 Double_t diff1 = sqrt(pow(x1-xr,2)+pow(y1-yr,2));
170 Double_t pointPhi0 = atan2(fPoint[1]-fCenterY,fPoint[0]-fCenterX);
171 Double_t trackPhi0 = atan2(fFirstPoint[1]-fCenterY,fFirstPoint[0]-fCenterX);
172 if(fabs(trackPhi0-pointPhi0)>pi){
173 if(trackPhi0<pointPhi0) trackPhi0 += 2*pi;
174 else pointPhi0 += 2*pi;
176 Double_t stot = -fQ * (pointPhi0-trackPhi0) * fRadius ;
177 fPoint[2] = fFirstPoint[2] + stot * fTanl;
179 fPointPsi = pointPhi0 - fQ * 0.5 * pi;
180 if(fPointPsi<0.) fPointPsi+= 2*pi;
181 fPointPsi = fmod(fPointPsi, 2*pi);
183 return IsPoint(kTRUE);
186 Bool_t AliL3Track::CalculateEdgePoint(Double_t angle){
187 // Global coordinate: crossing point with y = ax; a=tan(angle);
189 Double_t rmin=80; //min Radius of TPC
190 Double_t rmax=260; //max Radius of TPC
192 Double_t a = tan(angle);
193 Double_t pp=(fCenterX+a*fCenterY)/(1+pow(a,2));
194 Double_t qq=(pow(fCenterX,2)+pow(fCenterY,2)-pow(fRadius,2))/(1+pow(a,2));
195 Double_t racine = pp*pp-qq;
196 if(racine<0) return IsPoint(kFALSE); //no Point
197 Double_t rootRacine = sqrt(racine);
198 Double_t x0 = pp+rootRacine;
199 Double_t x1 = pp-rootRacine;
203 Double_t r0 = sqrt(pow(x0,2)+pow(y0,2));
204 Double_t r1 = sqrt(pow(x1,2)+pow(y1,2));
205 //find the right crossing point:
206 //inside the TPC modules
209 if(r0>rmin&&r0<rmax){
210 Double_t da=atan2(y0,x0);
212 if(fabs(da-angle)<0.5)
215 if(r1>rmin&&r1<rmax){
216 Double_t da=atan2(y1,y1);
218 if(fabs(da-angle)<0.5)
221 if(!(ok0||ok1)) return IsPoint(kFALSE); //no Point
224 Double_t diff0 = sqrt(pow(fFirstPoint[0]-x0,2)+pow(fFirstPoint[1]-y0,2));
225 Double_t diff1 = sqrt(pow(fFirstPoint[0]-x1,2)+pow(fFirstPoint[1]-y1,2));
226 if(diff0<diff1) ok1 = kFALSE; //use ok0
227 else ok0 = kFALSE; //use ok1
229 if(ok0){fPoint[0]=x0; fPoint[1]=y0;}
230 else {fPoint[0]=x1; fPoint[1]=y1;}
232 Double_t pointPhi0 = atan2(fPoint[1]-fCenterY,fPoint[0]-fCenterX);
233 Double_t trackPhi0 = atan2(fFirstPoint[1]-fCenterY,fFirstPoint[0]-fCenterX);
234 if(fabs(trackPhi0-pointPhi0)>pi){
235 if(trackPhi0<pointPhi0) trackPhi0 += 2*pi;
236 else pointPhi0 += 2*pi;
238 Double_t stot = -fQ * (pointPhi0-trackPhi0) * fRadius ;
239 fPoint[2] = fFirstPoint[2] + stot * fTanl;
241 fPointPsi = pointPhi0 - fQ * 0.5 * pi;
242 if(fPointPsi<0.) fPointPsi+= 2*pi;
243 fPointPsi = fmod(fPointPsi, 2*pi);
245 return IsPoint(kTRUE);
248 Bool_t AliL3Track::CalculatePoint(Double_t xplane){
249 // Local coordinate: crossing point with x plane
251 Double_t racine = pow(fRadius,2)-pow(xplane-fCenterX,2);
252 if(racine<0) return IsPoint(kFALSE);
253 Double_t rootRacine = sqrt(racine);
255 Double_t y0 = fCenterY + rootRacine;
256 Double_t y1 = fCenterY - rootRacine;
257 //Double_t diff0 = sqrt(pow(fFirstPoint[0]-xplane)+pow(fFirstPoint[1]-y0));
258 //Double_t diff1 = sqrt(pow(fFirstPoint[0]-xplane)+pow(fFirstPoint[1]-y1));
259 Double_t diff0 = fabs(y0-fFirstPoint[1]);
260 Double_t diff1 = fabs(y1-fFirstPoint[1]);
263 if(diff0<diff1) fPoint[1]=y0;
266 Double_t pointPhi0 = atan2(fPoint[1]-fCenterY,fPoint[0]-fCenterX);
267 Double_t trackPhi0 = atan2(fFirstPoint[1]-fCenterY,fFirstPoint[0]-fCenterX);
268 if(fabs(trackPhi0-pointPhi0)>pi){
269 if(trackPhi0<pointPhi0) trackPhi0 += 2*pi;
270 else pointPhi0 += 2*pi;
272 Double_t stot = -fQ * (pointPhi0-trackPhi0) * fRadius ;
273 fPoint[2] = fFirstPoint[2] + stot * fTanl;
275 fPointPsi = pointPhi0 - fQ * 0.5 * pi;
276 if(fPointPsi<0.) fPointPsi+= 2*pi;
277 fPointPsi = fmod(fPointPsi, 2*pi);
279 return IsPoint(kTRUE);