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source: git/modules/TrackSmearing.cc@ b438187

Last change on this file since b438187 was f298e48, checked in by Roberto Preghenella <preghenella@…>, 5 years ago

Add radius (distance from beam line) to formula parameterisations

also redefines the DelphesFormula::Eval function to allow one to
include future parameters for parameterisations that can be
taken from Candidates in a generalised way.

  • Property mode set to 100644
File size: 12.4 KB
Line 
1/** \class TrackSmearing
2 *
3 * Performs d0, dZ, p, Theta, Phi smearing of tracks.
4 *
5 * \authors A. Hart, M. Selvaggi
6 *
7*/
8
9#include "modules/TrackSmearing.h"
10
11#include "classes/DelphesClasses.h"
12#include "classes/DelphesFactory.h"
13#include "classes/DelphesFormula.h"
14
15#include "ExRootAnalysis/ExRootClassifier.h"
16#include "ExRootAnalysis/ExRootFilter.h"
17#include "ExRootAnalysis/ExRootResult.h"
18
19#include "TDatabasePDG.h"
20#include "TFile.h"
21#include "TFormula.h"
22#include "TLorentzVector.h"
23#include "TMath.h"
24#include "TObjArray.h"
25#include "TProfile2D.h"
26#include "TRandom3.h"
27#include "TString.h"
28
29#include <algorithm>
30#include <iostream>
31#include <sstream>
32#include <stdexcept>
33
34using namespace std;
35
36//------------------------------------------------------------------------------
37
38TrackSmearing::TrackSmearing() :
39 fD0Formula(0), fDZFormula(0), fPFormula(0), fCtgThetaFormula(0), fPhiFormula(0), fItInputArray(0)
40{
41 fD0Formula = new DelphesFormula;
42 fDZFormula = new DelphesFormula;
43 fPFormula = new DelphesFormula;
44 fCtgThetaFormula = new DelphesFormula;
45 fPhiFormula = new DelphesFormula;
46}
47
48//------------------------------------------------------------------------------
49
50TrackSmearing::~TrackSmearing()
51{
52 if(fD0Formula) delete fD0Formula;
53 if(fDZFormula) delete fDZFormula;
54 if(fPFormula) delete fPFormula;
55 if(fCtgThetaFormula) delete fCtgThetaFormula;
56 if(fPhiFormula) delete fPhiFormula;
57}
58
59//------------------------------------------------------------------------------
60
61void TrackSmearing::Init()
62{
63 fBz = GetDouble("Bz", 0.0);
64
65 // read resolution formula
66
67 // !!! IF WE WANT TO KEEP ROOT INPUT !!!
68 if(string(GetString("D0ResolutionFormula", "0.0")) != "0.0")
69 {
70 fD0Formula->Compile(GetString("D0ResolutionFormula", "0.0"));
71 fUseD0Formula = true;
72 }
73 else
74 {
75 fD0ResolutionFile = GetString("D0ResolutionFile", "errors.root");
76 fD0ResolutionHist = GetString("D0ResolutionHist", "d0");
77 fUseD0Formula = false;
78 }
79 if(string(GetString("DZResolutionFormula", "0.0")) != "0.0")
80 {
81 fDZFormula->Compile(GetString("DZResolutionFormula", "0.0"));
82 fUseDZFormula = true;
83 }
84 else
85 {
86 fDZResolutionFile = GetString("DZResolutionFile", "errors.root");
87 fDZResolutionHist = GetString("DZResolutionHist", "dz");
88 fUseDZFormula = false;
89 }
90 if(string(GetString("PResolutionFormula", "0.0")) != "0.0")
91 {
92 fPFormula->Compile(GetString("PResolutionFormula", "0.0"));
93 fUsePFormula = true;
94 }
95 else
96 {
97 fPResolutionFile = GetString("PResolutionFile", "errors.root");
98 fPResolutionHist = GetString("PResolutionHist", "p");
99 fUsePFormula = false;
100 }
101 if(string(GetString("CtgThetaResolutionFormula", "0.0")) != "0.0")
102 {
103 fCtgThetaFormula->Compile(GetString("CtgThetaResolutionFormula", "0.0"));
104 fUseCtgThetaFormula = true;
105 }
106 else
107 {
108 fCtgThetaResolutionFile = GetString("CtgThetaResolutionFile", "errors.root");
109 fCtgThetaResolutionHist = GetString("CtgThetaResolutionHist", "ctgTheta");
110 fUseCtgThetaFormula = false;
111 }
112 if(string(GetString("PhiResolutionFormula", "0.0")) != "0.0")
113 {
114 fPhiFormula->Compile(GetString("PhiResolutionFormula", "0.0"));
115 fUsePhiFormula = true;
116 }
117 else
118 {
119 fPhiResolutionFile = GetString("PhiResolutionFile", "errors.root");
120 fPhiResolutionHist = GetString("PhiResolutionHist", "phi");
121 fUsePhiFormula = false;
122 }
123
124 fApplyToPileUp = GetBool("ApplyToPileUp", true);
125
126 // import input array
127
128 fInputArray = ImportArray(GetString("InputArray", "ParticlePropagator/stableParticles"));
129 fItInputArray = fInputArray->MakeIterator();
130
131 // import beamspot
132 try
133 {
134 fBeamSpotInputArray = ImportArray(GetString("BeamSpotInputArray", "BeamSpotFilter/beamSpotParticle"));
135 }
136 catch(runtime_error &e)
137 {
138 fBeamSpotInputArray = 0;
139 }
140
141 // create output array
142
143 fOutputArray = ExportArray(GetString("OutputArray", "stableParticles"));
144}
145
146//------------------------------------------------------------------------------
147
148void TrackSmearing::Finish()
149{
150 if(fItInputArray) delete fItInputArray;
151}
152
153//------------------------------------------------------------------------------
154
155void TrackSmearing::Process()
156{
157 Int_t iCandidate = 0;
158 TLorentzVector beamSpotPosition;
159 Candidate *candidate, *mother;
160 Double_t pt, eta, e, d0, d0Error, trueD0, dz, dzError, trueDZ, p, pError, trueP, ctgTheta, ctgThetaError, trueCtgTheta, phi, phiError, truePhi;
161 Double_t x, y, z, t, px, py, pz, theta;
162 Double_t q, r;
163 Double_t x_c, y_c, r_c, phi_0;
164 Double_t rcu, rc2, xd, yd, zd;
165 const Double_t c_light = 2.99792458E8;
166 TProfile2D *d0ErrorHist = NULL,
167 *dzErrorHist = NULL,
168 *pErrorHist = NULL,
169 *ctgThetaErrorHist = NULL,
170 *phiErrorHist = NULL;
171
172 if(!fBeamSpotInputArray || fBeamSpotInputArray->GetSize() == 0)
173 beamSpotPosition.SetXYZT(0.0, 0.0, 0.0, 0.0);
174 else
175 {
176 Candidate &beamSpotCandidate = *((Candidate *)fBeamSpotInputArray->At(0));
177 beamSpotPosition = beamSpotCandidate.Position;
178 }
179
180 if(!fUseD0Formula)
181 {
182 TFile *fin = TFile::Open(fD0ResolutionFile.c_str());
183 d0ErrorHist = (TProfile2D *)fin->Get(fD0ResolutionHist.c_str());
184 d0ErrorHist->SetDirectory(0);
185 fin->Close();
186 }
187 if(!fUseDZFormula)
188 {
189 TFile *fin = TFile::Open(fDZResolutionFile.c_str());
190 dzErrorHist = (TProfile2D *)fin->Get(fDZResolutionHist.c_str());
191 dzErrorHist->SetDirectory(0);
192 fin->Close();
193 }
194 if(!fUsePFormula)
195 {
196 TFile *fin = TFile::Open(fPResolutionFile.c_str());
197 pErrorHist = (TProfile2D *)fin->Get(fPResolutionHist.c_str());
198 pErrorHist->SetDirectory(0);
199 fin->Close();
200 }
201 if(!fUseCtgThetaFormula)
202 {
203 TFile *fin = TFile::Open(fCtgThetaResolutionFile.c_str());
204 ctgThetaErrorHist = (TProfile2D *)fin->Get(fCtgThetaResolutionHist.c_str());
205 ctgThetaErrorHist->SetDirectory(0);
206 fin->Close();
207 }
208 if(!fUsePhiFormula)
209 {
210 TFile *fin = TFile::Open(fPhiResolutionFile.c_str());
211 phiErrorHist = (TProfile2D *)fin->Get(fPhiResolutionHist.c_str());
212 phiErrorHist->SetDirectory(0);
213 fin->Close();
214 }
215
216 fItInputArray->Reset();
217 while((candidate = static_cast<Candidate *>(fItInputArray->Next())))
218 {
219
220 const TLorentzVector &momentum = candidate->Momentum;
221 const TLorentzVector &position = candidate->InitialPosition;
222
223 pt = momentum.Pt();
224 eta = momentum.Eta();
225 e = momentum.E();
226
227 d0 = trueD0 = candidate->D0;
228 dz = trueDZ = candidate->DZ;
229
230 p = trueP = candidate->P;
231 ctgTheta = trueCtgTheta = candidate->CtgTheta;
232 phi = truePhi = candidate->Phi;
233
234 if(fUseD0Formula)
235 d0Error = fD0Formula->Eval(pt, eta, phi, e, candidate);
236 else
237 {
238 Int_t xbin, ybin;
239
240 xbin = pt < d0ErrorHist->GetXaxis()->GetXmax() ? d0ErrorHist->GetXaxis()->FindBin(pt) : d0ErrorHist->GetXaxis()->GetBinCenter(d0ErrorHist->GetXaxis()->GetNbins());
241 ybin = d0ErrorHist->GetYaxis()->FindBin(TMath::Abs(eta));
242 d0Error = d0ErrorHist->GetBinContent(xbin, ybin);
243 if(!d0Error)
244 d0Error = -1.0;
245 }
246 if(d0Error < 0.0)
247 continue;
248
249 if(fUseDZFormula)
250 dzError = fDZFormula->Eval(pt, eta, phi, e, candidate);
251 else
252 {
253 Int_t xbin, ybin;
254
255 xbin = pt < dzErrorHist->GetXaxis()->GetXmax() ? dzErrorHist->GetXaxis()->FindBin(pt) : dzErrorHist->GetXaxis()->GetBinCenter(dzErrorHist->GetXaxis()->GetNbins());
256 ybin = dzErrorHist->GetYaxis()->FindBin(TMath::Abs(eta));
257 dzError = dzErrorHist->GetBinContent(xbin, ybin);
258 if(!dzError)
259 dzError = -1.0;
260 }
261 if(dzError < 0.0)
262 continue;
263
264 if(fUsePFormula)
265 pError = fPFormula->Eval(pt, eta, phi, e, candidate) * p;
266 else
267 {
268 Int_t xbin, ybin;
269
270 xbin = pt < pErrorHist->GetXaxis()->GetXmax() ? pErrorHist->GetXaxis()->FindBin(pt) : pErrorHist->GetXaxis()->GetBinCenter(pErrorHist->GetXaxis()->GetNbins());
271 ybin = pErrorHist->GetYaxis()->FindBin(TMath::Abs(eta));
272 pError = pErrorHist->GetBinContent(xbin, ybin) * p;
273 if(!pError)
274 pError = -1.0;
275 }
276 if(pError < 0.0)
277 continue;
278
279 if(fUseCtgThetaFormula)
280 ctgThetaError = fCtgThetaFormula->Eval(pt, eta, phi, e, candidate);
281 else
282 {
283 Int_t xbin, ybin;
284
285 xbin = pt < ctgThetaErrorHist->GetXaxis()->GetXmax() ? ctgThetaErrorHist->GetXaxis()->FindBin(pt) : ctgThetaErrorHist->GetXaxis()->GetBinCenter(ctgThetaErrorHist->GetXaxis()->GetNbins());
286 ybin = ctgThetaErrorHist->GetYaxis()->FindBin(TMath::Abs(eta));
287 ctgThetaError = ctgThetaErrorHist->GetBinContent(xbin, ybin);
288 if(!ctgThetaError)
289 ctgThetaError = -1.0;
290 }
291 if(ctgThetaError < 0.0)
292 continue;
293
294 if(fUsePhiFormula)
295 phiError = fPhiFormula->Eval(pt, eta, phi, e, candidate);
296 else
297 {
298 Int_t xbin, ybin;
299
300 xbin = pt < phiErrorHist->GetXaxis()->GetXmax() ? phiErrorHist->GetXaxis()->FindBin(pt) : phiErrorHist->GetXaxis()->GetBinCenter(phiErrorHist->GetXaxis()->GetNbins());
301 ybin = phiErrorHist->GetYaxis()->FindBin(TMath::Abs(eta));
302 phiError = phiErrorHist->GetBinContent(xbin, ybin);
303 if(!phiError)
304 phiError = -1.0;
305 }
306 if(phiError < 0.0)
307 continue;
308
309 if(fApplyToPileUp || !candidate->IsPU)
310 {
311 d0 = gRandom->Gaus(d0, d0Error);
312 dz = gRandom->Gaus(dz, dzError);
313 p = gRandom->Gaus(p, pError);
314 ctgTheta = gRandom->Gaus(ctgTheta, ctgThetaError);
315 phi = gRandom->Gaus(phi, phiError);
316 }
317
318 if(p < 0.0) continue;
319 while(phi > TMath::Pi()) phi -= TMath::TwoPi();
320 while(phi <= -TMath::Pi()) phi += TMath::TwoPi();
321
322 mother = candidate;
323 candidate = static_cast<Candidate *>(candidate->Clone());
324 candidate->D0 = d0;
325 candidate->DZ = dz;
326 candidate->P = p;
327 candidate->CtgTheta = ctgTheta;
328 candidate->Phi = phi;
329
330 theta = TMath::ACos(ctgTheta / TMath::Sqrt(1.0 + ctgTheta * ctgTheta));
331 candidate->Momentum.SetPx(p * TMath::Cos(phi) * TMath::Sin(theta));
332 candidate->Momentum.SetPy(p * TMath::Sin(phi) * TMath::Sin(theta));
333 candidate->Momentum.SetPz(p * TMath::Cos(theta));
334 candidate->Momentum.SetE(candidate->Momentum.Pt() * TMath::CosH(eta));
335 candidate->PT = candidate->Momentum.Pt();
336
337 x = position.X();
338 y = position.Y();
339 z = position.Z();
340 t = position.T();
341 px = candidate->Momentum.Px();
342 py = candidate->Momentum.Py();
343 pz = candidate->Momentum.Pz();
344 pt = candidate->Momentum.Pt();
345
346 // -- solve for delta: d0' = ( (x+delta)*py' - (y+delta)*px' )/pt'
347
348 candidate->InitialPosition.SetX(x + ((px * y - py * x + d0 * pt) / (py - px)));
349 candidate->InitialPosition.SetY(y + ((px * y - py * x + d0 * pt) / (py - px)));
350 x = candidate->InitialPosition.X();
351 y = candidate->InitialPosition.Y();
352 candidate->InitialPosition.SetZ(z + ((pz * (px * (x - beamSpotPosition.X()) + py * (y - beamSpotPosition.Y())) + pt * pt * (dz - z)) / (pt * pt)));
353 z = candidate->InitialPosition.Z();
354
355 candidate->InitialPosition.SetT(t);
356
357 // update closest approach
358 x *= 1.0E-3;
359 y *= 1.0E-3;
360 z *= 1.0E-3;
361
362 q = candidate->Charge;
363
364 r = pt / (q * fBz) * 1.0E9 / c_light; // in [m]
365 phi_0 = TMath::ATan2(py, px); // [rad] in [-pi, pi]
366
367 // 2. helix axis coordinates
368 x_c = x + r * TMath::Sin(phi_0);
369 y_c = y - r * TMath::Cos(phi_0);
370 r_c = TMath::Hypot(x_c, y_c);
371
372 rcu = TMath::Abs(r);
373 rc2 = r_c * r_c;
374
375 // calculate coordinates of closest approach to track circle in transverse plane xd, yd, zd
376 xd = x_c * x_c * x_c - x_c * rcu * r_c + x_c * y_c * y_c;
377 xd = (rc2 > 0.0) ? xd / rc2 : -999;
378 yd = y_c * (-rcu * r_c + rc2);
379 yd = (rc2 > 0.0) ? yd / rc2 : -999;
380 zd = z + (TMath::Sqrt(xd * xd + yd * yd) - TMath::Sqrt(x * x + y * y)) * pz / pt;
381
382 candidate->Xd = xd * 1.0E3;
383 candidate->Yd = yd * 1.0E3;
384 candidate->Zd = zd * 1.0E3;
385
386 if(fApplyToPileUp || !candidate->IsPU)
387 {
388 candidate->ErrorD0 = d0Error;
389 candidate->ErrorDZ = dzError;
390 candidate->ErrorP = pError;
391 candidate->ErrorCtgTheta = ctgThetaError;
392 candidate->ErrorPhi = phiError;
393 candidate->ErrorPT = ptError(p, ctgTheta, pError, ctgThetaError);
394 candidate->TrackResolution = pError / p;
395 }
396
397 candidate->AddCandidate(mother);
398 fOutputArray->Add(candidate);
399
400 iCandidate++;
401 }
402}
403
404Double_t TrackSmearing::ptError(const Double_t p, const Double_t ctgTheta, const Double_t dP, const Double_t dCtgTheta)
405{
406 Double_t a, b;
407 a = (p * p * ctgTheta * ctgTheta * dCtgTheta * dCtgTheta) / ((ctgTheta * ctgTheta + 1) * (ctgTheta * ctgTheta + 1) * (ctgTheta * ctgTheta + 1));
408 b = (dP * dP) / (ctgTheta * ctgTheta + 1);
409 return sqrt(a + b);
410}
411
412//------------------------------------------------------------------------------
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