d88f97cc |
1 | #include "AliTrack.h" |
2 | |
3 | ClassImp(AliTrack) // Class implementation to enable ROOT I/O |
4 | |
5 | AliTrack::AliTrack() |
6 | { |
7 | // Default constructor |
8 | // All variables initialised to 0 |
9 | fDecays=0; |
10 | Reset(); |
11 | } |
12 | /////////////////////////////////////////////////////////////////////////// |
13 | AliTrack::~AliTrack() |
14 | { |
15 | // Destructor to delete memory allocated for decay tracks array |
16 | if (fDecays) |
17 | { |
18 | fDecays->Delete(); |
19 | delete fDecays; |
20 | fDecays=0; |
21 | } |
22 | } |
23 | /////////////////////////////////////////////////////////////////////////// |
24 | void AliTrack::Reset() |
25 | { |
26 | // Reset all variables to 0 |
27 | fM=0; |
28 | fQ=0; |
29 | fNdec=0; |
30 | Double_t a[4]={0,0,0,0}; |
31 | SetVector(a,"sph"); |
32 | if (fDecays) |
33 | { |
34 | fDecays->Delete(); |
35 | delete fDecays; |
36 | fDecays=0; |
37 | } |
38 | } |
39 | /////////////////////////////////////////////////////////////////////////// |
40 | void AliTrack::Set3Momentum(Ali3Vector& p) |
41 | { |
42 | // Set the track parameters according to the 3-momentum p |
43 | Double_t E=sqrt(p.Dot(p)+fM*fM); |
44 | SetVector(E,p); |
45 | } |
46 | /////////////////////////////////////////////////////////////////////////// |
47 | void AliTrack::Set4Momentum(Ali4Vector& p) |
48 | { |
49 | // Set the track parameters according to the 4-momentum p |
50 | Double_t E=p.GetScalar(); |
51 | Ali3Vector pv=p.Get3Vector(); |
52 | SetVector(E,pv); |
53 | |
54 | Double_t m2=p.Dot(p); |
55 | fM=0; |
56 | if (m2 > 0.) fM=sqrt(m2); |
57 | } |
58 | /////////////////////////////////////////////////////////////////////////// |
59 | void AliTrack::SetMass(Double_t m) |
60 | { |
61 | // Set the particle mass |
62 | fM=m; |
63 | Ali3Vector p=Get3Vector(); |
64 | Double_t E=sqrt(p.Dot(p)+fM*fM); |
65 | SetVector(E,p); |
66 | } |
67 | /////////////////////////////////////////////////////////////////////////// |
68 | void AliTrack::SetCharge(Float_t q) |
69 | { |
70 | // Set the particle charge |
71 | fQ=q; |
72 | } |
73 | /////////////////////////////////////////////////////////////////////////// |
74 | void AliTrack::Info(TString f) |
75 | { |
76 | // Provide track information within the coordinate frame f |
77 | cout << " *AliTrack::Info* Mass : " << fM << " Charge : " << fQ |
78 | << " Momentum : " << GetMomentum() << " Ntracks : " << fNdec << endl; |
79 | cout << " "; |
80 | Ali4Vector::Info(f); |
81 | } |
82 | /////////////////////////////////////////////////////////////////////////// |
83 | void AliTrack::List(TString f) |
84 | { |
85 | // Provide current track and decay level 1 information within coordinate frame f |
86 | |
87 | Info(f); // Information of the current track |
88 | |
89 | // Decay products of this track |
90 | AliTrack* td; |
91 | for (Int_t id=1; id<=fNdec; id++) |
92 | { |
93 | td=GetDecayTrack(id); |
94 | if (td) |
95 | { |
96 | cout << " ---Level 1 sec. track no. " << id << endl; |
97 | cout << " "; |
98 | td->Info(f); |
99 | } |
100 | else |
101 | { |
102 | cout << " *AliTrack::List* Error : No decay track present." << endl; |
103 | } |
104 | } |
105 | } |
106 | /////////////////////////////////////////////////////////////////////////// |
107 | void AliTrack::ListAll(TString f) |
108 | { |
109 | // Provide complete track and decay information within the coordinate frame f |
110 | |
111 | Info(f); // Information of the current track |
112 | |
113 | AliTrack* t=this; |
114 | Dump(t,1,f); // Information of all decay products |
115 | } |
116 | ////////////////////////////////////////////////////////////////////////// |
117 | void AliTrack::Dump(AliTrack* t,Int_t n,TString f) |
118 | { |
119 | // Recursively provide the info of all decay levels of this track |
120 | AliTrack* td; |
121 | for (Int_t id=1; id<=t->GetNdecay(); id++) |
122 | { |
123 | td=t->GetDecayTrack(id); |
124 | if (td) |
125 | { |
126 | cout << " ---Level " << n << " sec. track no. " << id << endl; |
127 | cout << " "; |
128 | td->Info(f); |
129 | |
130 | // Go for next decay level of this decay track recursively |
131 | Dump(td,n+1,f); |
132 | } |
133 | else |
134 | { |
135 | cout << " *AliTrack::Dump* Error : No decay track present." << endl; |
136 | } |
137 | } |
138 | } |
139 | ////////////////////////////////////////////////////////////////////////// |
140 | Double_t AliTrack::GetMomentum() |
141 | { |
142 | // Provide the value of the track 3-momentum |
143 | Ali3Vector p=Get3Vector(); |
144 | return sqrt(p.Dot(p)); |
145 | } |
146 | /////////////////////////////////////////////////////////////////////////// |
147 | Ali3Vector AliTrack::Get3Momentum() |
148 | { |
149 | // Provide the track 3-momentum |
150 | return (Ali3Vector)Get3Vector(); |
151 | } |
152 | /////////////////////////////////////////////////////////////////////////// |
153 | Double_t AliTrack::GetMass() |
154 | { |
155 | // Provide the particle mass |
156 | return fM; |
157 | } |
158 | /////////////////////////////////////////////////////////////////////////// |
159 | Float_t AliTrack::GetCharge() |
160 | { |
161 | // Provide the particle charge |
162 | return fQ; |
163 | } |
164 | /////////////////////////////////////////////////////////////////////////// |
165 | Double_t AliTrack::GetEnergy() |
166 | { |
167 | // Provide the particle's energy |
168 | return GetScalar(); |
169 | } |
170 | /////////////////////////////////////////////////////////////////////////// |
171 | void AliTrack::Decay(Double_t m1,Double_t m2,Double_t thcms,Double_t phicms) |
172 | { |
173 | // Perform 2-body decay of current track |
174 | // m1 : mass of decay product 1 |
175 | // m2 : mass of decay product 2 |
176 | // thcms : cms theta decay angle (in rad.) of m1 |
177 | // phicms : cms phi decay angle (in rad.) of m1 |
178 | |
179 | fNdec=2; // it's a 2-body decay |
180 | |
181 | // Compute the 4-momenta of the decay products in the cms |
182 | // Note : p2=p1=pnorm for a 2-body decay |
183 | Double_t e1=((fM*fM)+(m1*m1)-(m2*m2))/(2.*fM); |
184 | Double_t e2=((fM*fM)+(m2*m2)-(m1*m1))/(2.*fM); |
185 | Double_t pnorm=(e1*e1)-(m1*m1); |
186 | if (pnorm>0.) |
187 | { |
188 | pnorm=sqrt(pnorm); |
189 | } |
190 | else |
191 | { |
192 | pnorm=0; |
193 | } |
194 | |
195 | Double_t a[3]; |
196 | a[0]=pnorm; |
197 | a[1]=thcms; |
198 | a[2]=phicms; |
199 | Ali3Vector p; |
200 | p.SetVector(a,"sph"); |
201 | |
202 | Ali4Vector pprim1; |
203 | pprim1.SetVector(e1,p); |
204 | |
205 | Ali4Vector pprim2; |
206 | p*=-1; |
207 | pprim2.SetVector(e2,p); |
208 | |
209 | // Determine boost parameters from the parent particle |
210 | Double_t E=GetScalar(); |
211 | p=Get3Vector(); |
212 | Ali4Vector pmu; |
213 | pmu.SetVector(E,p); |
214 | |
215 | AliBoost q; |
216 | q.Set4Momentum(pmu); |
217 | |
218 | Ali4Vector p1=q.Inverse(pprim1); // Boost decay product 1 |
219 | Ali4Vector p2=q.Inverse(pprim2); // Boost decay product 2 |
220 | |
221 | // Enter the boosted data into the decay tracks array |
222 | if (fDecays) |
223 | { |
224 | fDecays->Delete(); |
225 | delete fDecays; |
226 | } |
227 | fDecays=new TObjArray(); |
228 | |
229 | fDecays->Add(new AliTrack); |
230 | ((AliTrack*)fDecays->At(0))->Set4Momentum(p1); |
231 | fDecays->Add(new AliTrack); |
232 | ((AliTrack*)fDecays->At(1))->Set4Momentum(p2); |
233 | |
234 | // Set the mass values to m1 and m2 to omit roundoff errors |
235 | ((AliTrack*)fDecays->At(0))->SetMass(m1); |
236 | ((AliTrack*)fDecays->At(1))->SetMass(m2); |
237 | } |
238 | /////////////////////////////////////////////////////////////////////////// |
239 | Int_t AliTrack::GetNdecay() |
240 | { |
241 | // Provide the number of decay produced tracks |
242 | return fNdec; |
243 | } |
244 | /////////////////////////////////////////////////////////////////////////// |
245 | AliTrack* AliTrack::GetDecayTrack(Int_t j) |
246 | { |
247 | // Provide decay produced track number j |
248 | // Note : j=1 denotes the first decay track |
249 | if ((j >= 1) && (j <= fNdec)) |
250 | { |
251 | return (AliTrack*)fDecays->At(j-1); |
252 | } |
253 | else |
254 | { |
255 | cout << " *AliTrack* decay track number : " << j << " out of range." << endl; |
256 | cout << " -- Decay track number 1 (if any) returned." << endl; |
257 | return (AliTrack*)fDecays->At(0); |
258 | } |
259 | } |
260 | /////////////////////////////////////////////////////////////////////////// |