1 /**************************************************************************
2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
7 * Permission to use, copy, modify and distribute this software and its *
8 * documentation strictly for non-commercial purposes is hereby granted *
9 * without fee, provided that the above copyright notice appears in all *
10 * copies and that both the copyright notice and this permission notice *
11 * appear in the supporting documentation. The authors make no claims *
12 * about the suitability of this software for any purpose. It is *
13 * provided "as is" without express or implied warranty. *
14 **************************************************************************/
18 Revision 1.7 2001/05/10 12:32:27 jbarbosa
19 Changed call to SetTrack.
21 Revision 1.6 2001/02/23 17:39:02 jbarbosa
22 Removed verbose output.
24 Revision 1.5 2001/02/23 17:25:08 jbarbosa
25 Re-definition of IntPH() to accomodate for wire sag effect.
27 Revision 1.4 2000/12/01 17:37:44 morsch
28 Replace in argument of SetTrack(..) string constant by kPFeedBackPhoton.
30 Revision 1.3 2000/10/03 21:44:09 morsch
31 Use AliSegmentation and AliHit abstract base classes.
33 Revision 1.2 2000/10/02 21:28:12 fca
34 Removal of useless dependecies via forward declarations
36 Revision 1.1 2000/06/12 15:29:37 jbarbosa
41 #include "AliRICHResponseV0.h"
42 #include "AliSegmentation.h"
48 #include <TParticle.h>
49 //___________________________________________
50 ClassImp(AliRICHResponseV0)
52 Float_t AliRICHResponseV0::IntPH(Float_t eloss, Float_t yhit)
54 // Get number of electrons and return charge
57 nel= Int_t(eloss/fEIonisation);
66 //printf("Voltage:%d, Yhit:%f\n",fVoltage, yhit);
70 gain_var = 9e-6*TMath::Power(yhit,4) + 2e-7*TMath::Power(yhit,3) - 0.0316*TMath::Power(yhit,2) - 3e-4*yhit + 25.367;
71 //gain_var = 9e-5*TMath::Power(yhit,4) + 2e-6*TMath::Power(yhit,3) - 0.316*TMath::Power(yhit,2) - 3e-3*yhit + 253.67;
74 gain_var = 8e-6*TMath::Power(yhit,4) + 2e-7*TMath::Power(yhit,3) - 0.0283*TMath::Power(yhit,2) - 2e-4*yhit + 23.015;
76 gain_var = 7e-6*TMath::Power(yhit,4) + 1e-7*TMath::Power(yhit,3) - 0.0254*TMath::Power(yhit,2) - 2e-4*yhit + 20.888;
78 gain_var = 6e-6*TMath::Power(yhit,4) + 8e-8*TMath::Power(yhit,3) - 0.0227*TMath::Power(yhit,2) - 1e-4*yhit + 18.961;
80 gain_var = gain_var/100;
81 //printf("Yhit:%f, Gain variation:%f\n",yhit,gain_var);
83 Float_t gain = (fChargeSlope + fChargeSlope*gain_var)*.9;
84 //printf(" Yhit:%f, Gain variation:%f\n",yhit, gain);
86 for (Int_t i=1;i<=nel;i++) {
87 charge -= gain*TMath::Log(gRandom->Rndm());
92 for (Int_t i=1;i<=nel;i++) {
93 charge -= fChargeSlope*TMath::Log(gRandom->Rndm());
100 Float_t AliRICHResponseV0::IntPH(Float_t yhit)
103 // Get number of electrons and return charge, for a single photon
112 gain_var = 9e-6*TMath::Power(yhit,4) + 2e-7*TMath::Power(yhit,3) - 0.0316*TMath::Power(yhit,2) - 3e-4*yhit + 25.367;
113 //gain_var = 9e-5*TMath::Power(yhit,4) + 2e-6*TMath::Power(yhit,3) - 0.316*TMath::Power(yhit,2) - 3e-3*yhit + 253.67;
116 gain_var = 8e-6*TMath::Power(yhit,4) + 2e-7*TMath::Power(yhit,3) - 0.0283*TMath::Power(yhit,2) - 2e-4*yhit + 23.015;
118 gain_var = 7e-6*TMath::Power(yhit,4) + 1e-7*TMath::Power(yhit,3) - 0.0254*TMath::Power(yhit,2) - 2e-4*yhit + 20.888;
120 gain_var = 6e-6*TMath::Power(yhit,4) + 8e-8*TMath::Power(yhit,3) - 0.0227*TMath::Power(yhit,2) - 1e-4*yhit + 18.961;
122 gain_var = gain_var/100;
123 //printf(" Yhit:%f, Gain variation:%f\n",yhit, gain_var);
125 Float_t gain = (fChargeSlope + fChargeSlope*gain_var)*.9;
127 charge -= gain*TMath::Log(gRandom->Rndm());
128 //printf(" Yhit:%f, Gain variation:%f\n",yhit, gain);
132 charge -= fChargeSlope*TMath::Log(gRandom->Rndm());
139 // -------------------------------------------
140 Float_t AliRICHResponseV0::IntXY(AliSegmentation * segmentation)
143 const Float_t kInversePitch = 1/fPitch;
146 // Integration limits defined by segmentation model
149 Float_t xi1, xi2, yi1, yi2;
150 segmentation->IntegrationLimits(xi1,xi2,yi1,yi2);
152 xi1=xi1*kInversePitch;
153 xi2=xi2*kInversePitch;
154 yi1=yi1*kInversePitch;
155 yi2=yi2*kInversePitch;
157 //printf("Integration Limits: %f-%f, %f-%f\n",xi1,xi2,yi1,yi2);
159 //printf("KInversePitch:%f\n",kInversePitch);
162 // The Mathieson function
163 Double_t ux1=fSqrtKx3*TMath::TanH(fKx2*xi1);
164 Double_t ux2=fSqrtKx3*TMath::TanH(fKx2*xi2);
166 Double_t uy1=fSqrtKy3*TMath::TanH(fKy2*yi1);
167 Double_t uy2=fSqrtKy3*TMath::TanH(fKy2*yi2);
169 //printf("Integration Data: %f-%f, %f-%f\n",ux1,ux2,uy1,uy2);
171 //printf("%f %f %f %f\n",fSqrtKx3,fKx2,fKy4,fKx4);
173 response=4.*fKx4*(TMath::ATan(ux2)-TMath::ATan(ux1))*fKy4*(TMath::ATan(uy2)-TMath::ATan(uy1));
175 //printf("Response:%f\n",response);
181 Int_t AliRICHResponseV0::FeedBackPhotons(Float_t *source, Float_t qtot)
184 // Generate FeedBack photons
192 Float_t cthf, ranf[2], phif, enfp = 0, sthf;
194 Float_t e1[3], e2[3], e3[3];
199 Float_t pol[3], mom[4];
200 TLorentzVector position;
202 // Determine number of feedback photons
204 // Get weight of current particle
205 TParticle *current = (TParticle*)
206 (*gAlice->Particles())[gAlice->CurrentTrack()];
208 ifeed = Int_t(current->GetWeight()/100+0.5);
209 ipart = gMC->TrackPid();
210 fp = fAlphaFeedback * qtot;
211 nfp = gRandom->Poisson(fp);
213 // This call to fill the time of flight
214 gMC->TrackPosition(position);
215 //printf("Track position: %f %f %f %15.12f\n", position[0],position[1],position[2],position[3]);
218 for (i = 0; i <nfp; i++) {
222 cthf = ranf[0] * 2 - 1.;
223 if (cthf < 0) continue;
224 sthf = TMath::Sqrt((1 - cthf) * (1 + cthf));
225 phif = ranf[1] * 2 * TMath::Pi();
227 gMC->Rndm(&random, 1);
230 } else if (random <= .7) {
236 dir[0] = sthf * TMath::Sin(phif);
238 dir[2] = sthf * TMath::Cos(phif);
239 gMC->Gdtom(dir, mom, 2);
243 mom[3] = TMath::Sqrt(mom[0]*mom[0]+mom[1]*mom[1]+mom[2]*mom[2]);
244 //printf("Dir %f %f %f\n",dir[0],dir[1],dir[2]);
245 //printf("Momentum %15.12f %15.12f %15.12f\n",mom[0],mom[1],mom[2]);
246 //printf("Energy %e\n", mom[3]);
262 for(j=0;j<3;j++) vmod+=e1[j]*e1[j];
263 if (!vmod) for(j=0;j<3;j++) {
269 for(j=0;j<3;j++) vmod+=e2[j]*e2[j];
270 if (!vmod) for(j=0;j<3;j++) {
277 for(j=0;j<3;j++) vmod+=e1[j]*e1[j];
278 vmod=TMath::Sqrt(1/vmod);
279 for(j=0;j<3;j++) e1[j]*=vmod;
282 for(j=0;j<3;j++) vmod+=e2[j]*e2[j];
283 vmod=TMath::Sqrt(1/vmod);
284 for(j=0;j<3;j++) e2[j]*=vmod;
287 phi = ranf[0] * 2 * TMath::Pi();
288 for(j=0;j<3;j++) pol[j]=e1[j]*TMath::Sin(phi)+e2[j]*TMath::Cos(phi);
289 gMC->Gdtom(pol, pol, 2);
291 // Put photon on the stack and label it as feedback (51, 52)
294 gAlice->SetTrack(Int_t(1), gAlice->CurrentTrack(), Int_t(50000051),
295 mom[0],mom[1],mom[2],mom[3],source[0],source[1],source[2],position[3],pol[0],pol[1],pol[2],
296 kPFeedBackPhoton, nt, 1.);
298 //printf("Adding feedback with tof %f and going to %f %f %f\n",position[3],mom[0],mom[1],mom[2]);
301 //printf("feedbacks produced:%d\n",sNfeed);