5a31e9df |
1 | #include "AliD0Trigger.h" |
2 | #include <TMath.h> |
3 | #include "AliITStrackV2.h" |
4 | #include "AliL3Transform.h" |
5 | #include <TVector3.h> |
6 | |
7 | ClassImp(AliD0Trigger) |
8 | |
9 | AliD0Trigger::AliD0Trigger() |
10 | { |
11 | posTrack=0; |
12 | negTrack=0; |
13 | } |
14 | AliD0Trigger::AliD0Trigger(double c[4],double b,double pv[3]) |
15 | { |
16 | posTrack=0; |
17 | negTrack=0; |
18 | cutV0low=c[0]; |
19 | cutV0high=c[1]; |
20 | cutInvMass=c[2]; |
21 | cutPointAngle=c[3]; |
22 | Bfield=b; |
23 | primaryVertex[0]=pv[0]; |
24 | primaryVertex[1]=pv[1]; |
25 | primaryVertex[2]=pv[2]; |
26 | } |
27 | AliD0Trigger::AliD0Trigger(AliITStrackV2 * posT, AliITStrackV2 * negT) |
28 | { |
29 | posTrack=posT; |
30 | negTrack=negT; |
31 | } |
32 | |
33 | |
34 | AliD0Trigger::~AliD0Trigger() |
35 | { |
36 | |
37 | } |
38 | |
39 | void AliD0Trigger::SetTracks(AliITStrackV2 * posT, AliITStrackV2 * negT){ |
40 | posTrack=posT; |
41 | negTrack=negT; |
42 | } |
43 | bool AliD0Trigger::FindInvMass() { |
44 | |
45 | double mD0 = 1.8645; |
46 | double mPi = 0.13957; |
47 | double mKa = 0.49368; |
48 | |
49 | double mom2[2],momTot2,energy[2]; |
50 | |
51 | mom2[0]=pow(momenta[0],2)+pow(momenta[1],2)+pow(momenta[2],2); |
52 | mom2[1]=pow(momenta[3],2)+pow(momenta[4],2)+pow(momenta[5],2); |
53 | |
54 | momTot2 = pow(momenta[0]+momenta[3],2)+pow(momenta[1]+momenta[4],2)+pow(momenta[2]+momenta[5],2); |
55 | |
56 | // D0 -> K- Pi+ |
57 | energy[1] = sqrt(pow(mKa,2)+mom2[1]); |
58 | energy[0] = sqrt(pow(mPi,2)+mom2[0]); |
59 | |
60 | double minvD0 = sqrt((energy[0]+energy[1])*(energy[0]+energy[1])-momTot2); |
61 | |
62 | // D0bar -> K+ Pi- |
63 | energy[0] = sqrt(mKa*mKa+mom2[0]); |
64 | energy[1] = sqrt(mPi*mPi+mom2[1]); |
65 | |
66 | double minvD0bar = sqrt((energy[0]+energy[1])*(energy[0]+energy[1])-momTot2); |
67 | |
68 | if(fabs(minvD0-mD0) < cutInvMass) return true; |
69 | if(fabs(minvD0bar-mD0) < cutInvMass) return true; |
70 | return false; |
71 | |
72 | } |
73 | bool AliD0Trigger::FindV0(){ |
74 | |
75 | bool goodV0=false; |
76 | |
77 | double Gxpos=posTrack->GetX()*cos(posTrack->GetAlpha())-posTrack->GetY()*sin(posTrack->GetAlpha()); |
78 | double Gypos=posTrack->GetX()*sin(posTrack->GetAlpha())+posTrack->GetY()*cos(posTrack->GetAlpha()); |
79 | double Gxneg=negTrack->GetX()*cos(negTrack->GetAlpha())-negTrack->GetY()*sin(negTrack->GetAlpha()); |
80 | double Gyneg=negTrack->GetX()*sin(negTrack->GetAlpha())+negTrack->GetY()*cos(negTrack->GetAlpha()); |
81 | |
82 | double r1=fabs(1/(AliL3Transform::GetBFact()*Bfield*posTrack->Get1Pt())); |
83 | double r2=fabs(1/(AliL3Transform::GetBFact()*Bfield*negTrack->Get1Pt())); |
84 | //double a1=posTrack->GetX()-(r1*cos(asin(posTrack->GetSnp())+TMath::PiOver2())); |
85 | //double a2=negTrack->GetX()-(r1*cos(asin(negTrack->GetSnp())-TMath::PiOver2())); |
86 | //double b1=posTrack->GetY()-(r1*sin(asin(posTrack->GetSnp())+TMath::PiOver2())); |
87 | //double b2=negTrack->GetY()-(r1*sin(asin(negTrack->GetSnp())-TMath::PiOver2())); |
88 | |
89 | double a1=Gxpos-(r1*cos(posTrack->GetAlpha()+asin(posTrack->GetSnp())+TMath::PiOver2())); |
90 | double a2=Gxneg-(r2*cos(negTrack->GetAlpha()+asin(negTrack->GetSnp())-TMath::PiOver2())); |
91 | double b1=Gypos-(r1*sin(posTrack->GetAlpha()+asin(posTrack->GetSnp())+TMath::PiOver2())); |
92 | double b2=Gyneg-(r2*sin(negTrack->GetAlpha()+asin(negTrack->GetSnp())-TMath::PiOver2())); |
93 | |
94 | double a3=a1-a2; |
95 | double b3=b1-b2; |
96 | double r3=sqrt(pow(a3,2)+pow(b3,2)); |
97 | |
98 | if(r3<r1+r2){ |
99 | double q=a1-a2; |
100 | double p=2*(b1-b2); |
101 | double t=pow(r2,2)-pow(r2,2)+pow(b1,2)-pow(b2,2)-pow(q,2); |
102 | |
103 | double Fa=pow(p,2)+(4*pow(q,2)); |
104 | double Fb=-(2*t*p+8*pow(q,2)*b1); |
105 | double Fc=pow(t,2)-(4*pow(q,2)*pow(r1,2))+(4*pow(q,2)*pow(b1,2)); |
106 | |
107 | if(pow(Fb,2)-(4*Fa*Fc)>=0){ |
108 | double y1=(-Fb+(sqrt(pow(Fb,2)-(4*Fa*Fc))))/(2*Fa); //noe feil her. floating point |
109 | double y2=(-Fb-(sqrt(pow(Fb,2)-(4*Fa*Fc))))/(2*Fa); //trolig negativ under rot |
110 | |
111 | double x1=sqrt(pow(r1,2)-pow((y1-b1),2))+a1; |
112 | double x2=sqrt(pow(r1,2)-pow((y2-b1),2))+a1; |
113 | double x3=-sqrt(pow(r1,2)-pow((y1-b1),2))+a1; |
114 | double x4=-sqrt(pow(r1,2)-pow((y2-b1),2))+a1; |
115 | |
116 | double V01=sqrt(pow(x1,2)+pow(y1,2)); |
117 | double V02=sqrt(pow(x2,2)+pow(y2,2)); |
118 | double V03=sqrt(pow(x3,2)+pow(y1,2)); |
119 | double V04=sqrt(pow(x4,2)+pow(y2,2)); |
120 | |
121 | double V0[4]={V01,V02,V03,V04}; |
122 | int index=0; |
123 | |
124 | double nearestV0=V0[0]; |
125 | for(int i=1;i<4;i++){ |
126 | if(nearestV0>V0[i]){ |
127 | nearestV0=V0[i]; |
128 | index=i; |
129 | } |
130 | } |
131 | if(nearestV0<cutV0high && nearestV0>cutV0low){ |
132 | goodV0=true; |
133 | switch (index){ |
134 | case 0 : bestV0[0]=x1;bestV0[1]=y1;bestV0[0]=0.;break; |
135 | case 1 : bestV0[0]=x2;bestV0[1]=y2;bestV0[0]=0.;break; |
136 | case 2 : bestV0[0]=x3;bestV0[1]=y1;bestV0[0]=0.;break; |
137 | case 3 : bestV0[0]=x4;bestV0[1]=y2;bestV0[0]=0.;break; |
138 | default : printf("Can't set V0"); |
139 | } |
140 | } |
141 | } |
142 | } |
143 | return goodV0; |
144 | } |
145 | void AliD0Trigger::FindMomentaAtVertex(){ |
146 | |
147 | double r1=fabs(1/(AliL3Transform::GetBFact()*Bfield*posTrack->Get1Pt())); |
148 | double r2=fabs(1/(AliL3Transform::GetBFact()*Bfield*negTrack->Get1Pt())); |
149 | |
150 | double Gx1=posTrack->GetX()*cos(posTrack->GetAlpha())-posTrack->GetY()*sin(posTrack->GetAlpha()); |
151 | double Gy1=posTrack->GetX()*sin(posTrack->GetAlpha())+posTrack->GetY()*cos(posTrack->GetAlpha()); |
152 | double Gx2=negTrack->GetX()*cos(negTrack->GetAlpha())-negTrack->GetY()*sin(negTrack->GetAlpha()); |
153 | double Gy2=negTrack->GetX()*sin(negTrack->GetAlpha())+negTrack->GetY()*cos(negTrack->GetAlpha()); |
154 | |
155 | double centerx1=Gx1-(r1*cos(posTrack->GetAlpha()+asin(posTrack->GetSnp())+TMath::PiOver2())); |
156 | double centerx2=Gx2-(r2*cos(negTrack->GetAlpha()+asin(negTrack->GetSnp())-TMath::PiOver2())); |
157 | double centery1=Gy1-(r1*sin(posTrack->GetAlpha()+asin(posTrack->GetSnp())+TMath::PiOver2())); |
158 | double centery2=Gy2-(r2*sin(negTrack->GetAlpha()+asin(negTrack->GetSnp())-TMath::PiOver2())); |
159 | |
160 | double a1=sqrt(pow(Gx1-bestV0[0],2)+pow(Gy1-bestV0[1],2)); |
161 | double b1=sqrt(pow(bestV0[0]-centerx1,2)+pow(bestV0[1]-centery1,2)); |
162 | double c1=sqrt(pow(Gx1-centerx1,2)+pow(Gy1-centery1,2)); |
163 | double a2=sqrt(pow(Gx2-bestV0[0],2)+pow(Gy2-bestV0[1],2)); |
164 | double b2=sqrt(pow(bestV0[0]-centerx2,2)+pow(bestV0[1]-centery2,2)); |
165 | double c2=sqrt(pow(Gx2-centerx2,2)+pow(Gy2-centery2,2)); |
166 | |
167 | double alpha1=acos((pow(b1,2)+pow(c1,2)-pow(a1,2))/(2*b1*c1)); |
168 | double alpha2=acos((pow(b2,2)+pow(c2,2)-pow(a2,2))/(2*b2*c2)); |
169 | |
170 | double sign1=0; |
171 | double sign2=0; |
172 | |
173 | if((sqrt(pow(Gx1,2)+pow(Gy1,2)))>(sqrt(pow(bestV0[0],2)+pow(bestV0[1],2)))) |
174 | sign1=-1; |
175 | else |
176 | sign1=1; |
177 | if((sqrt(pow(Gx2,2)+pow(Gy2,2)))>(sqrt(pow(bestV0[0],2)+pow(bestV0[1],2)))) |
178 | sign2=1; |
179 | else |
180 | sign2=-1; |
181 | |
182 | double psi1=(posTrack->GetAlpha()+asin(posTrack->GetSnp()))+(sign1*alpha1); |
183 | double psi2=(negTrack->GetAlpha()+asin(negTrack->GetSnp()))+(sign2*alpha2); |
184 | |
185 | double ptP = 1./fabs(posTrack->Get1Pt()); |
186 | momenta[0] = ptP*cos(psi1); |
187 | momenta[1] = ptP*sin(psi1); |
188 | momenta[2] = ptP*posTrack->GetTgl(); |
189 | |
190 | double ptN = 1./fabs(negTrack->Get1Pt()); |
191 | momenta[3] = ptN*cos(psi2); |
192 | momenta[4] = ptN*sin(psi2); |
193 | momenta[5] = ptN*negTrack->GetTgl(); |
194 | |
195 | } |
196 | Bool_t AliD0Trigger::PointingAngle(){ |
197 | |
198 | TVector3 mom(momenta[0]+momenta[3],momenta[1]+momenta[4],momenta[2]+momenta[5]); |
199 | TVector3 flight(bestV0[0]-primaryVertex[0],bestV0[1]-primaryVertex[1],bestV0[2]-primaryVertex[2]); |
200 | |
201 | double pta = mom.Angle(flight); |
202 | |
203 | if(cos(pta)<cutPointAngle) |
204 | return true; |
205 | else |
206 | return false; |
207 | } |