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 //_________________________________________________________________________
19 // Implementation version v1 of PHOS Manager class
21 // Layout EMC + PPSD has name GPS2:
22 // Produces cumulated hits
24 // Layout EMC + CPV has name IHEP:
25 // Produces hits for CPV, cumulated hits
27 // Layout EMC + CPV + PPSD has name GPS:
28 // Produces hits for CPV, cumulated hits
30 //*-- Author: Yves Schutz (SUBATECH)
33 // --- ROOT system ---
39 #include "TParticle.h"
41 // --- Standard library ---
46 // --- AliRoot header files ---
48 #include "AliPHOSv1.h"
49 #include "AliPHOSHit.h"
50 #include "AliPHOSCPVDigit.h"
54 #include "AliPHOSGeometry.h"
55 #include "AliPHOSQAIntCheckable.h"
56 #include "AliPHOSQAFloatCheckable.h"
57 #include "AliPHOSQAMeanChecker.h"
61 //____________________________________________________________________________
62 AliPHOSv1::AliPHOSv1():
65 // default ctor: initialze data memebers
71 fLightYieldMean = 0. ;
72 fIntrinsicPINEfficiency = 0. ;
73 fLightYieldAttenuation = 0. ;
74 fRecalibrationFactor = 0. ;
75 fElectronsPerGeV = 0. ;
82 //____________________________________________________________________________
83 AliPHOSv1::AliPHOSv1(const char *name, const char *title):
88 // - fHits (the "normal" one), which retains the hits associated with
89 // the current primary particle being tracked
90 // (this array is reset after each primary has been tracked).
95 // We do not want to save in TreeH the raw hits
96 // But save the cumulated hits instead (need to create the branch myself)
97 // It is put in the Digit Tree because the TreeH is filled after each primary
98 // and the TreeD at the end of the event (branch is set in FinishEvent() ).
100 fHits= new TClonesArray("AliPHOSHit",1000) ;
101 gAlice->AddHitList(fHits) ;
105 fIshunt = 2 ; // All hits are associated with primary particles
107 //Photoelectron statistics:
108 // The light yield is a poissonian distribution of the number of
109 // photons created in the PbWo4 crystal, calculated using following formula
110 // NumberOfPhotons = EnergyLost * LightYieldMean* APDEfficiency *
111 // exp (-LightYieldAttenuation * DistanceToPINdiodeFromTheHit);
112 // LightYieldMean is parameter calculated to be over 47000 photons per GeV
113 // APDEfficiency is 0.02655
114 // k_0 is 0.0045 from Valery Antonenko
115 // The number of electrons created in the APD is
116 // NumberOfElectrons = APDGain * LightYield
117 // The APD Gain is 300
118 fLightYieldMean = 47000;
119 fIntrinsicPINEfficiency = 0.02655 ; //APD= 0.1875/0.1271 * 0.018 (PIN)
120 fLightYieldAttenuation = 0.0045 ;
121 fRecalibrationFactor = 13.418/ fLightYieldMean ;
122 fElectronsPerGeV = 2.77e+8 ;
124 fLightFactor = fLightYieldMean * fIntrinsicPINEfficiency ;
125 fAPDFactor = (fRecalibrationFactor/100.) * fAPDGain ;
128 Int_t nb = GetGeometry()->GetNModules() ;
131 fQAHitsMul = new AliPHOSQAIntCheckable("HitsM") ;
132 fQATotEner = new AliPHOSQAFloatCheckable("TotEn") ;
133 fQAHitsMulB = new TClonesArray("AliPHOSQAIntCheckable",nb) ;
134 fQAHitsMulB->SetOwner() ;
135 fQATotEnerB = new TClonesArray("AliPHOSQAFloatCheckable", nb);
136 fQATotEnerB->SetOwner() ;
139 for ( i = 0 ; i < nb ; i++ ) {
140 sprintf(tempo, "HitsMB%d", i+1) ;
141 new( (*fQAHitsMulB)[i]) AliPHOSQAIntCheckable(tempo) ;
142 sprintf(tempo, "TotEnB%d", i+1) ;
143 new( (*fQATotEnerB)[i] ) AliPHOSQAFloatCheckable(tempo) ;
146 AliPHOSQAMeanChecker * hmc = new AliPHOSQAMeanChecker("HitsMul", 100. ,25.) ;
147 AliPHOSQAMeanChecker * emc = new AliPHOSQAMeanChecker("TotEner", 10. ,5.) ;
148 AliPHOSQAMeanChecker * bhmc = new AliPHOSQAMeanChecker("HitsMulB", 100. ,5.) ;
149 AliPHOSQAMeanChecker * bemc = new AliPHOSQAMeanChecker("TotEnerB", 2. ,.5) ;
151 // associate checkables and checkers
152 fQAHitsMul->AddChecker(hmc) ;
153 fQATotEner->AddChecker(emc) ;
154 for ( i = 0 ; i < nb ; i++ ) {
155 (static_cast<AliPHOSQAIntCheckable*>((*fQAHitsMulB)[i]))->AddChecker(bhmc) ;
156 (static_cast<AliPHOSQAFloatCheckable*>((*fQATotEnerB)[i]))->AddChecker(bemc) ;
161 //____________________________________________________________________________
162 AliPHOSv1::~AliPHOSv1()
173 fQAHitsMulB->Delete() ;
178 fQATotEnerB->Delete() ;
184 //____________________________________________________________________________
185 void AliPHOSv1::AddHit(Int_t shunt, Int_t primary, Int_t tracknumber, Int_t Id, Float_t * hits)
187 // Add a hit to the hit list.
188 // A PHOS hit is the sum of all hits in a single crystal from one primary and within some time gate
193 Bool_t deja = kFALSE ;
194 AliPHOSGeometry * geom = GetGeometry() ;
196 newHit = new AliPHOSHit(shunt, primary, tracknumber, Id, hits) ;
198 for ( hitCounter = fNhits-1 ; hitCounter >= 0 && !deja ; hitCounter-- ) {
199 curHit = dynamic_cast<AliPHOSHit*>((*fHits)[hitCounter]) ;
200 if(curHit->GetPrimary() != primary) break ;
201 // We add hits with the same primary, while GEANT treats primaries succesively
202 if( *curHit == *newHit ) {
209 new((*fHits)[fNhits]) AliPHOSHit(*newHit) ;
210 // get the block Id number
212 geom->AbsToRelNumbering(Id, relid) ;
213 // and fill the relevant QA checkable (only if in PbW04)
214 if ( relid[1] == 0 ) {
215 fQAHitsMul->Update(1) ;
216 (static_cast<AliPHOSQAIntCheckable*>((*fQAHitsMulB)[relid[0]-1]))->Update(1) ;
224 //____________________________________________________________________________
225 void AliPHOSv1::FinishPrimary()
227 // called at the end of each track (primary) by AliRun
228 // hits are reset for each new track
229 // accumulate the total hit-multiplicity
231 // fQAHitsMul->Update( fHits->GetEntriesFast() ) ;
235 //____________________________________________________________________________
236 void AliPHOSv1::FinishEvent()
238 // called at the end of each event by AliRun
239 // accumulate the hit-multiplicity and total energy per block
240 // if the values have been updated check it
243 if ( fQATotEner->HasChanged() ) {
244 fQATotEner->CheckMe() ;
245 fQATotEner->Reset() ;
250 if ( fQAHitsMulB && fQATotEnerB ) {
251 for (i = 0 ; i < GetGeometry()->GetNModules() ; i++) {
252 AliPHOSQAIntCheckable * ci = static_cast<AliPHOSQAIntCheckable*>((*fQAHitsMulB)[i]) ;
253 AliPHOSQAFloatCheckable* cf = static_cast<AliPHOSQAFloatCheckable*>((*fQATotEnerB)[i]) ;
254 if ( ci->HasChanged() ) {
258 if ( cf->HasChanged() ) {
265 // check the total multiplicity
268 if ( fQAHitsMul->HasChanged() ) {
269 fQAHitsMul->CheckMe() ;
270 fQAHitsMul->Reset() ;
274 //____________________________________________________________________________
275 void AliPHOSv1::StepManager(void)
277 // Accumulates hits as long as the track stays in a single crystal or CPV gas Cell
279 Int_t relid[4] ; // (box, layer, row, column) indices
280 Int_t absid ; // absolute cell ID number
281 Float_t xyzte[5]={-1000.,-1000.,-1000.,0.,0.} ; // position wrt MRS, time and energy deposited
282 TLorentzVector pos ; // Lorentz vector of the track current position
285 Int_t tracknumber = gAlice->CurrentTrack() ;
286 Int_t primary = gAlice->GetPrimary( gAlice->CurrentTrack() );
287 TString name = GetGeometry()->GetName() ;
291 if( gMC->CurrentVolID(copy) == gMC->VolId("PCPQ") &&
292 (gMC->IsTrackEntering() ) &&
293 gMC->TrackCharge() != 0) {
295 gMC -> TrackPosition(pos);
297 Float_t xyzm[3], xyzd[3] ;
299 for (i=0; i<3; i++) xyzm[i] = pos[i];
300 gMC -> Gmtod (xyzm, xyzd, 1); // transform coordinate from master to daughter system
302 Float_t xyd[3]={0,0,0} ; //local position of the entering
307 // Current momentum of the hit's track in the local ref. system
308 TLorentzVector pmom ; //momentum of the particle initiated hit
309 gMC -> TrackMomentum(pmom);
310 Float_t pm[3], pd[3];
314 gMC -> Gmtod (pm, pd, 2); // transform 3-momentum from master to daughter system
319 // Digitize the current CPV hit:
321 // 1. find pad response and
322 gMC->CurrentVolOffID(3,moduleNumber);
325 TClonesArray *cpvDigits = new TClonesArray("AliPHOSCPVDigit",0); // array of digits for current hit
326 CPVDigitize(pmom,xyd,moduleNumber,cpvDigits);
331 Int_t idigit,ndigits;
333 // 2. go through the current digit list and sum digits in pads
335 ndigits = cpvDigits->GetEntriesFast();
336 for (idigit=0; idigit<ndigits-1; idigit++) {
337 AliPHOSCPVDigit *cpvDigit1 = dynamic_cast<AliPHOSCPVDigit*>(cpvDigits->UncheckedAt(idigit));
338 Float_t x1 = cpvDigit1->GetXpad() ;
339 Float_t z1 = cpvDigit1->GetYpad() ;
340 for (Int_t jdigit=idigit+1; jdigit<ndigits; jdigit++) {
341 AliPHOSCPVDigit *cpvDigit2 = dynamic_cast<AliPHOSCPVDigit*>(cpvDigits->UncheckedAt(jdigit));
342 Float_t x2 = cpvDigit2->GetXpad() ;
343 Float_t z2 = cpvDigit2->GetYpad() ;
344 if (x1==x2 && z1==z2) {
345 Float_t qsum = cpvDigit1->GetQpad() + cpvDigit2->GetQpad() ;
346 cpvDigit2->SetQpad(qsum) ;
347 cpvDigits->RemoveAt(idigit) ;
351 cpvDigits->Compress() ;
353 // 3. add digits to temporary hit list fTmpHits
355 ndigits = cpvDigits->GetEntriesFast();
356 for (idigit=0; idigit<ndigits; idigit++) {
357 AliPHOSCPVDigit *cpvDigit = dynamic_cast<AliPHOSCPVDigit*>(cpvDigits->UncheckedAt(idigit));
358 relid[0] = moduleNumber + 1 ; // CPV (or PHOS) module number
359 relid[1] =-1 ; // means CPV
360 relid[2] = cpvDigit->GetXpad() ; // column number of a pad
361 relid[3] = cpvDigit->GetYpad() ; // row number of a pad
363 // get the absolute Id number
364 GetGeometry()->RelToAbsNumbering(relid, absid) ;
366 // add current digit to the temporary hit list
368 xyzte[3] = gMC->TrackTime() ;
369 xyzte[4] = cpvDigit->GetQpad() ; // amplitude in a pad
370 primary = -1; // No need in primary for CPV
371 AddHit(fIshunt, primary, tracknumber, absid, xyzte);
373 if (cpvDigit->GetQpad() > 0.02) {
374 xmean += cpvDigit->GetQpad() * (cpvDigit->GetXpad() + 0.5);
375 zmean += cpvDigit->GetQpad() * (cpvDigit->GetYpad() + 0.5);
376 qsum += cpvDigit->GetQpad();
388 if(gMC->CurrentVolID(copy) == gMC->VolId("PXTL") ) { // We are inside a PBWO crystal
390 gMC->TrackPosition(pos) ;
395 Float_t global[3], local[3] ;
399 Float_t lostenergy = gMC->Edep();
401 //Put in the TreeK particle entering PHOS and all its parents
402 if ( gMC->IsTrackEntering() ){
404 gMC -> Gmtod (xyzte, xyzd, 1); // transform coordinate from master to daughter system
405 if (xyzd[1] > GetGeometry()->GetCrystalSize(1)/2-0.002 ||
406 xyzd[1] < -GetGeometry()->GetCrystalSize(1)/2+0.002) {
407 TParticle * part = 0 ;
408 Int_t parent = gAlice->CurrentTrack() ;
409 while ( parent != -1 ) {
410 part = gAlice->Particle(parent) ;
411 part->SetBit(kKeepBit);
412 parent = part->GetFirstMother() ;
416 if ( lostenergy != 0 ) { // Track is inside the crystal and deposits some energy
417 xyzte[3] = gMC->TrackTime() ;
419 gMC->CurrentVolOffID(10, moduleNumber) ; // get the PHOS module number ;
422 gMC->CurrentVolOffID(3, strip);
424 gMC->CurrentVolOffID(2, cell);
426 Int_t row = 1 + GetGeometry()->GetNZ() - strip % GetGeometry()->GetNZ() ;
427 Int_t col = (Int_t) TMath::Ceil((Double_t) strip/GetGeometry()->GetNZ()) -1 ;
429 absid = (moduleNumber-1)*GetGeometry()->GetNCristalsInModule() +
430 row + (col*GetGeometry()->GetEMCAGeometry()->GetNCellsInStrip() + cell-1)*GetGeometry()->GetNZ() ;
432 gMC->Gmtod(global, local, 1) ;
434 //Calculates the light yield, the number of photons produced in the
436 Float_t lightYield = gRandom->Poisson(fLightFactor * lostenergy *
437 exp(-fLightYieldAttenuation *
438 (local[1]+GetGeometry()->GetCrystalSize(1)/2.0 ))
441 //Calculates de energy deposited in the crystal
442 xyzte[4] = fAPDFactor * lightYield ;
444 // add current hit to the hit list
445 // Info("StepManager","%d %d", primary, tracknumber) ;
446 AddHit(fIshunt, primary,tracknumber, absid, xyzte);
448 // fill the relevant QA Checkables
449 fQATotEner->Update( xyzte[4] ) ; // total energy in PHOS
450 (static_cast<AliPHOSQAFloatCheckable*>((*fQATotEnerB)[moduleNumber-1]))->Update( xyzte[4] ) ; // energy in this block
452 } // there is deposited energy
453 } // we are inside a PHOS Xtal
457 //____________________________________________________________________________
458 void AliPHOSv1::CPVDigitize (TLorentzVector p, Float_t *zxhit, Int_t moduleNumber, TClonesArray *cpvDigits)
460 // ------------------------------------------------------------------------
461 // Digitize one CPV hit:
462 // On input take exact 4-momentum p and position zxhit of the hit,
463 // find the pad response around this hit and
464 // put the amplitudes in the pads into array digits
466 // Author: Yuri Kharlov (after Serguei Sadovsky)
468 // ------------------------------------------------------------------------
470 const Float_t kCelWr = GetGeometry()->GetPadSizePhi()/2; // Distance between wires (2 wires above 1 pad)
471 const Float_t kDetR = 0.1; // Relative energy fluctuation in track for 100 e-
472 const Float_t kdEdx = 4.0; // Average energy loss in CPV;
473 const Int_t kNgamz = 5; // Ionization size in Z
474 const Int_t kNgamx = 9; // Ionization size in Phi
475 const Float_t kNoise = 0.03; // charge noise in one pad
479 // Just a reminder on axes notation in the CPV module:
480 // axis Z goes along the beam
481 // axis X goes across the beam in the module plane
482 // axis Y is a normal to the module plane showing from the IP
484 Float_t hitX = zxhit[0];
485 Float_t hitZ =-zxhit[1];
488 Float_t pNorm = p.Py();
489 Float_t eloss = kdEdx;
491 //Info("CPVDigitize", "YVK : %f %f | %f %f %d", hitX, hitZ, pX, pZ, pNorm) ;
493 Float_t dZY = pZ/pNorm * GetGeometry()->GetCPVGasThickness();
494 Float_t dXY = pX/pNorm * GetGeometry()->GetCPVGasThickness();
495 gRandom->Rannor(rnor1,rnor2);
496 eloss *= (1 + kDetR*rnor1) *
497 TMath::Sqrt((1 + ( pow(dZY,2) + pow(dXY,2) ) / pow(GetGeometry()->GetCPVGasThickness(),2)));
498 Float_t zhit1 = hitZ + GetGeometry()->GetCPVActiveSize(1)/2 - dZY/2;
499 Float_t xhit1 = hitX + GetGeometry()->GetCPVActiveSize(0)/2 - dXY/2;
500 Float_t zhit2 = zhit1 + dZY;
501 Float_t xhit2 = xhit1 + dXY;
503 Int_t iwht1 = (Int_t) (xhit1 / kCelWr); // wire (x) coordinate "in"
504 Int_t iwht2 = (Int_t) (xhit2 / kCelWr); // wire (x) coordinate "out"
508 if (iwht1==iwht2) { // incline 1-wire hit
510 zxe[0][0] = (zhit1 + zhit2 - dZY*0.57735) / 2;
511 zxe[1][0] = (iwht1 + 0.5) * kCelWr;
513 zxe[0][1] = (zhit1 + zhit2 + dZY*0.57735) / 2;
514 zxe[1][1] = (iwht1 + 0.5) * kCelWr;
517 else if (TMath::Abs(iwht1-iwht2) != 1) { // incline 3-wire hit
519 Int_t iwht3 = (iwht1 + iwht2) / 2;
520 Float_t xwht1 = (iwht1 + 0.5) * kCelWr; // wire 1
521 Float_t xwht2 = (iwht2 + 0.5) * kCelWr; // wire 2
522 Float_t xwht3 = (iwht3 + 0.5) * kCelWr; // wire 3
523 Float_t xwr13 = (xwht1 + xwht3) / 2; // center 13
524 Float_t xwr23 = (xwht2 + xwht3) / 2; // center 23
525 Float_t dxw1 = xhit1 - xwr13;
526 Float_t dxw2 = xhit2 - xwr23;
527 Float_t egm1 = TMath::Abs(dxw1) / ( TMath::Abs(dxw1) + TMath::Abs(dxw2) + kCelWr );
528 Float_t egm2 = TMath::Abs(dxw2) / ( TMath::Abs(dxw1) + TMath::Abs(dxw2) + kCelWr );
529 Float_t egm3 = kCelWr / ( TMath::Abs(dxw1) + TMath::Abs(dxw2) + kCelWr );
530 zxe[0][0] = (dXY*(xwr13-xwht1)/dXY + zhit1 + zhit1) / 2;
532 zxe[2][0] = eloss * egm1;
533 zxe[0][1] = (dXY*(xwr23-xwht1)/dXY + zhit1 + zhit2) / 2;
535 zxe[2][1] = eloss * egm2;
536 zxe[0][2] = dXY*(xwht3-xwht1)/dXY + zhit1;
538 zxe[2][2] = eloss * egm3;
540 else { // incline 2-wire hit
542 Float_t xwht1 = (iwht1 + 0.5) * kCelWr;
543 Float_t xwht2 = (iwht2 + 0.5) * kCelWr;
544 Float_t xwr12 = (xwht1 + xwht2) / 2;
545 Float_t dxw1 = xhit1 - xwr12;
546 Float_t dxw2 = xhit2 - xwr12;
547 Float_t egm1 = TMath::Abs(dxw1) / ( TMath::Abs(dxw1) + TMath::Abs(dxw2) );
548 Float_t egm2 = TMath::Abs(dxw2) / ( TMath::Abs(dxw1) + TMath::Abs(dxw2) );
549 zxe[0][0] = (zhit1 + zhit2 - dZY*egm1) / 2;
551 zxe[2][0] = eloss * egm1;
552 zxe[0][1] = (zhit1 + zhit2 + dZY*egm2) / 2;
554 zxe[2][1] = eloss * egm2;
557 // Finite size of ionization region
559 Int_t nCellZ = GetGeometry()->GetNumberOfCPVPadsZ();
560 Int_t nCellX = GetGeometry()->GetNumberOfCPVPadsPhi();
561 Int_t nz3 = (kNgamz+1)/2;
562 Int_t nx3 = (kNgamx+1)/2;
563 cpvDigits->Expand(nIter*kNgamx*kNgamz);
564 TClonesArray &ldigits = *(static_cast<TClonesArray *>(cpvDigits));
566 for (Int_t iter=0; iter<nIter; iter++) {
568 Float_t zhit = zxe[0][iter];
569 Float_t xhit = zxe[1][iter];
570 Float_t qhit = zxe[2][iter];
571 Float_t zcell = zhit / GetGeometry()->GetPadSizeZ();
572 Float_t xcell = xhit / GetGeometry()->GetPadSizePhi();
573 if ( zcell<=0 || xcell<=0 ||
574 zcell>=nCellZ || xcell>=nCellX) return;
575 Int_t izcell = (Int_t) zcell;
576 Int_t ixcell = (Int_t) xcell;
577 Float_t zc = zcell - izcell - 0.5;
578 Float_t xc = xcell - ixcell - 0.5;
579 for (Int_t iz=1; iz<=kNgamz; iz++) {
580 Int_t kzg = izcell + iz - nz3;
581 if (kzg<=0 || kzg>nCellZ) continue;
582 Float_t zg = (Float_t)(iz-nz3) - zc;
583 for (Int_t ix=1; ix<=kNgamx; ix++) {
584 Int_t kxg = ixcell + ix - nx3;
585 if (kxg<=0 || kxg>nCellX) continue;
586 Float_t xg = (Float_t)(ix-nx3) - xc;
588 // Now calculate pad response
589 Float_t qpad = CPVPadResponseFunction(qhit,zg,xg);
590 qpad += kNoise*rnor2;
591 if (qpad<0) continue;
593 // Fill the array with pad response ID and amplitude
594 new(ldigits[cpvDigits->GetEntriesFast()]) AliPHOSCPVDigit(kxg,kzg,qpad);
600 //____________________________________________________________________________
601 Float_t AliPHOSv1::CPVPadResponseFunction(Float_t qhit, Float_t zhit, Float_t xhit) {
602 // ------------------------------------------------------------------------
603 // Calculate the amplitude in one CPV pad using the
604 // cumulative pad response function
605 // Author: Yuri Kharlov (after Serguei Sadovski)
607 // ------------------------------------------------------------------------
609 Double_t dz = GetGeometry()->GetPadSizeZ() / 2;
610 Double_t dx = GetGeometry()->GetPadSizePhi() / 2;
611 Double_t z = zhit * GetGeometry()->GetPadSizeZ();
612 Double_t x = xhit * GetGeometry()->GetPadSizePhi();
613 Double_t amplitude = qhit *
614 (CPVCumulPadResponse(z+dz,x+dx) - CPVCumulPadResponse(z+dz,x-dx) -
615 CPVCumulPadResponse(z-dz,x+dx) + CPVCumulPadResponse(z-dz,x-dx));
616 return (Float_t)amplitude;
619 //____________________________________________________________________________
620 Double_t AliPHOSv1::CPVCumulPadResponse(Double_t x, Double_t y) {
621 // ------------------------------------------------------------------------
622 // Cumulative pad response function
623 // It includes several terms from the CF decomposition in electrostatics
624 // Note: this cumulative function is wrong since omits some terms
625 // but the cell amplitude obtained with it is correct because
626 // these omitting terms cancel
627 // Author: Yuri Kharlov (after Serguei Sadovski)
629 // ------------------------------------------------------------------------
631 const Double_t kA=1.0;
632 const Double_t kB=0.7;
634 Double_t r2 = x*x + y*y;
636 Double_t cumulPRF = 0;
637 for (Int_t i=0; i<=4; i++) {
638 Double_t b1 = (2*i + 1) * kB;
639 cumulPRF += TMath::Power(-1,i) * TMath::ATan( xy / (b1*TMath::Sqrt(b1*b1 + r2)) );
641 cumulPRF *= kA/(2*TMath::Pi());