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Commit | Line | Data |
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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 | /////////////////////////////////////////////////////////////////////////// |