1 #ifndef REVE_MCHelixLine_H
2 #define REVE_MCHelixLine_H
4 #include <Reve/Track.h>
14 MCVertex() : x(0), y(0), z(0), t(0) {}
15 MCVertex(Float_t _x, Float_t _y, Float_t _z, Float_t _t=0) :
16 x(_x), y(_y), z(_z), t(_t) {}
18 Float_t Mag() const { return TMath::Sqrt(x*x+y*y+z*z);}
19 Float_t Mag2() const { return x*x+y*y+z*z;}
21 Float_t Perp() const { return TMath::Sqrt(x*x+y*y);}
22 Float_t Perp2() const { return x*x+y*y;}
23 Float_t R() const { return Perp(); }
25 MCVertex operator + (const MCVertex & b)
26 { return MCVertex(x + b.x, y + b.y, z + b.z, t + b.t); }
28 MCVertex operator - (const MCVertex & b)
29 { return MCVertex(x - b.x, y - b.y, z - b.z, t - b.t); }
31 MCVertex operator * (Float_t a)
32 { return MCVertex(a*x, a*y, a*z, a*t); }
34 MCVertex& operator +=(const MCVertex & b)
35 { x += b.x; y += b.y; z += b.z; t += b.t; return *this; }
41 MCStruct(const MCStruct&); // Not implemented
42 MCStruct& operator=(const MCStruct&); // Not implemented
44 TrackRnrStyle* fRnrMod;
45 std::vector<MCVertex>* fPoints;
47 Float_t fVelocity; // size of particle velocity
49 MCStruct(TrackRnrStyle* rs, MCVertex* v0 , Float_t vel, std::vector<MCVertex>* tpv) :
55 fPoints->push_back(fV);
57 virtual ~MCStruct() {}
60 /**************************************************************************/
62 /**************************************************************************/
64 struct MCHelix : public MCStruct
67 Float_t fA; // contains charge and magnetic field data
69 //parameters dependend pT and pZ size, set in init function
70 Float_t fLam; // momentum ratio pT/pZ
72 Float_t fPhiStep; // step size in xy projection, dependent of RnrMode and momentum
75 Int_t fN; // step number in helix;
76 Int_t NMax; // max number of points in helix
77 Float_t x_off, y_off; // offset for fitting daughters
81 MCHelix(TrackRnrStyle* rs, MCVertex* v0, Float_t vel,
82 std::vector<MCVertex>* tpv, Float_t a) :
83 MCStruct(rs, v0 , vel, tpv),
85 fLam (0), fR (0), fPhiStep (0), fTimeStep (0),
88 sin (0), cos (0), crosR (0)
91 void Init(Float_t pT, Float_t pZ)
100 fPhiStep = fRnrMod->fMinAng * TMath::DegToRad();
101 if (fRnrMod->fDelta < TMath::Abs(fR))
103 Float_t ang = 2*TMath::ACos(1 - fRnrMod->fDelta/TMath::Abs(fR));
104 if (ang < fPhiStep) fPhiStep = ang;
106 if (fA < 0) fPhiStep = -fPhiStep;
108 // printf("MCHelix::init (%f/%f) labda %f time step %e phi step %f \n", pT, pZ,fLam, fTimeStep,fPhiStep);
109 fTimeStep = TMath::Abs(fR*fPhiStep)*TMath::Sqrt(1+fLam*fLam)/fVelocity;
110 fTimeStep *= 0.01; //cm->m
112 sin = TMath::Sin(fPhiStep);
113 cos = TMath::Cos(fPhiStep);
118 // check steps for max orbits
119 NMax = Int_t(fRnrMod->fMaxOrbs*TMath::TwoPi()/TMath::Abs(fPhiStep));
120 // check steps for Z boundaries
123 nz = (fRnrMod->fMaxZ - fV.z)/(fLam*TMath::Abs(fR*fPhiStep));
125 nz = (-fRnrMod->fMaxZ - fV.z)/(fLam*TMath::Abs(fR*fPhiStep));
127 // printf("steps in helix line %d nz %f vz %f\n", NMax, nz, fV.z);
128 if (nz < NMax) NMax = Int_t(nz + 1);
130 // check steps if circles intersect
131 if(TMath::Sqrt(fV.x*fV.x+fV.y*fV.y) < fRnrMod->fMaxR + TMath::Abs(fR))
135 // printf("end steps in helix line %d \n", NMax);
139 void Step(Float_t &px, Float_t &py, Float_t &/*pz*/)
142 fV.x += (px*sin - py*(1 - cos))/fA + x_off;
143 fV.y += (py*sin + px*(1 - cos))/fA + y_off;
144 fV.z += fLam*TMath::Abs(fR*fPhiStep);
145 fPoints->push_back(fV);
146 Float_t px_t = px*cos - py*sin;
147 Float_t py_t = py*cos + px*sin;
154 Bool_t LoopToVertex(Float_t &px, Float_t &py, Float_t &pz,
155 Float_t ex, Float_t ey, Float_t ez)
157 Float_t p0x = px, p0y = py;
158 Float_t zs = fLam*TMath::Abs(fR*fPhiStep);
159 Float_t maxrsq = fRnrMod->fMaxR * fRnrMod->fMaxR;
160 Float_t fnsteps = (ez - fV.z)/zs;
161 Int_t nsteps = Int_t((ez - fV.z)/zs);
162 Float_t sinf = TMath::Sin(fnsteps*fPhiStep);
163 Float_t cosf = TMath::Cos(fnsteps*fPhiStep);
168 Float_t xf = fV.x + (px*sinf - py*(1 - cosf))/fA;
169 Float_t yf = fV.y + (py*sinf + px*(1 - cosf))/fA;
170 x_off = (ex - xf)/fnsteps;
171 y_off = (ey - yf)/fnsteps;
172 Float_t xforw, yforw, zforw;
173 for (Int_t l=0; l<nsteps; l++)
175 xforw = fV.x + (px*sin - py*(1 - cos))/fA + x_off;
176 yforw = fV.y + (py*sin + px*(1 - cos))/fA + y_off;
177 zforw = fV.z + fLam*TMath::Abs(fR*fPhiStep);
178 if (xforw*xforw+yforw*yforw > maxrsq ||
179 TMath::Abs(zforw) > fRnrMod->fMaxZ)
189 // set time to the end point
190 fV.t += TMath::Sqrt((fV.x-ex)*(fV.x-ex)+(fV.y-ey)*(fV.y-ey) +(fV.z-ez)*(fV.z-ez))/fVelocity;
191 fV.x = ex; fV.y = ey; fV.z = ez;
192 fPoints->push_back(fV);
195 { // fix momentum in the remaining part
196 Float_t cosr = TMath::Cos((fnsteps-nsteps)*fPhiStep);
197 Float_t sinr = TMath::Sin((fnsteps-nsteps)*fPhiStep);
198 Float_t px_t = px*cosr - py*sinr;
199 Float_t py_t = py*cosr + px*sinr;
203 { // calculate direction of faked px,py
204 Float_t pxf = (p0x*cosf - p0y*sinf)/TMath::Abs(fA) + x_off/fPhiStep;
205 Float_t pyf = (p0y*cosf + p0x*sinf)/TMath::Abs(fA) + y_off/fPhiStep;
206 Float_t fac = TMath::Sqrt((p0x*p0x + p0y*p0y) / (pxf*pxf + pyf*pyf));
213 Bool_t LoopToBounds(Float_t &px, Float_t &py, Float_t &pz)
215 // printf("MC helix loop_to_bounds\n");
219 // printf("NMax MC helix loop_to_bounds\n");
221 Float_t maxrsq = fRnrMod->fMaxR * fRnrMod->fMaxR;
224 forw.x = fV.x + (px*sin - py*(1 - cos))/fA + x_off;
225 forw.y = fV.y + (py*sin + px*(1 - cos))/fA + y_off;
226 forw.z = fV.z + fLam*TMath::Abs(fR*fPhiStep);
227 forw.t = fV.t + fTimeStep;
229 if (crosR && forw.Perp2() > maxrsq)
231 Float_t t = (fRnrMod->fMaxR - fV.R()) / (forw.R() - fV.R());
232 assert(t >= 0 && t <= 1);
233 fPoints->push_back(fV + (forw-fV)*t);
236 if (TMath::Abs(forw.z) > fRnrMod->fMaxZ)
238 Float_t t = (fRnrMod->fMaxZ - TMath::Abs(fV.z)) / TMath::Abs((forw.z - fV.z));
239 assert(t >= 0 && t <= 1);
240 fPoints->push_back(fV + (forw-fV)*t);
252 /**************************************************************************/
254 /**************************************************************************/
256 struct MCLine : public MCStruct
258 MCLine(TrackRnrStyle* rs, MCVertex* v0 ,Float_t vel, std::vector<MCVertex>* tpv):
259 MCStruct(rs, v0 , vel, tpv)
262 Bool_t InBounds(Float_t ex, Float_t ey, Float_t ez)
264 if(TMath::Abs(ez) > fRnrMod->fMaxZ ||
265 ex*ex + ey*ey > fRnrMod->fMaxR*fRnrMod->fMaxR)
271 void GotoVertex(Float_t x1, Float_t y1, Float_t z1)
273 fV.t += TMath::Sqrt((fV.x-x1)*(fV.x-x1)+(fV.y-y1)*(fV.y-y1)+(fV.z-z1)*(fV.z-z1))/fVelocity;
274 fV.x=x1; fV.y=y1; fV.z=z1;
275 fPoints->push_back(fV);
279 void GotoBounds( Float_t px, Float_t py, Float_t pz)
281 Float_t tZ = 0,Tb = 0;
282 // time where particle intersect +/- fMaxZ
284 tZ = (fRnrMod->fMaxZ - fV.z)/pz;
287 tZ = (-1)*(fRnrMod->fMaxZ + fV.z)/pz;
289 // time where particle intersects cylinder
291 Double_t a = px*px + py*py;
292 Double_t b = 2*(fV.x*px + fV.y*py);
293 Double_t c = fV.x*fV.x + fV.y*fV.y - fRnrMod->fMaxR*fRnrMod->fMaxR;
294 Double_t D = b*b - 4*a*c;
296 Double_t D_sqrt=TMath::Sqrt(D);
297 tR = ( -b - D_sqrt )/(2*a);
299 tR = ( -b + D_sqrt )/(2*a);
302 // compare the two times
303 Tb = tR < tZ ? tR : tZ;
308 GotoVertex(fV.x+px*Tb, fV.y+py*Tb, fV.z+ pz*Tb);