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cc80f89e | 1 | /************************************************************************** |
2 | * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. * | |
3 | * * | |
4 | * Author: The ALICE Off-line Project. * | |
5 | * Contributors are mentioned in the code where appropriate. * | |
6 | * * | |
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 | **************************************************************************/ | |
15 | ||
7d855b04 | 16 | /// \class AliDetectorParam |
17 | /// | |
18 | /// Paramter class for AliDetector | |
19 | /// | |
20 | /// \author Marian Ivanov, Uni. of Bratislava, ivanov@fmph.uniba.sk | |
cc80f89e | 21 | |
090026bf | 22 | #include <TMath.h> |
23 | #include <TObject.h> | |
24 | ||
cc80f89e | 25 | #include "AliDetectorParam.h" |
26 | ||
27 | ||
179c6296 | 28 | AliDetectorParam::AliDetectorParam() |
29 | :TNamed(), | |
30 | fBField(0.), | |
31 | fNPrimLoss(0.), | |
32 | fNTotalLoss(0.) | |
33 | { | |
7d855b04 | 34 | /// default constructor |
35 | ||
179c6296 | 36 | } |
cc80f89e | 37 | |
176aff27 | 38 | Float_t * AliDetectorParam::GetAnglesAccMomentum(Float_t *x, Int_t * /*index*/, Float_t *momentum, Float_t *angle) |
cc80f89e | 39 | { |
7d855b04 | 40 | /// calculates deflection angle of particle with longitudinal |
41 | /// longitudinal momentum[0] and transversal momentum momentum[1] | |
42 | /// at position (x,y,z) = (x[0],x[1],x[2]) | |
43 | /// angle[0] - deep angle | |
44 | /// angle[1] - magnetic deflection angle | |
45 | ||
cc80f89e | 46 | if (momentum==0) { |
47 | Float_t rtotal =TMath::Sqrt(x[0]*x[0]+x[1]*x[1]); | |
48 | if (rtotal==0) angle[0]=0; | |
7d855b04 | 49 | else |
cc80f89e | 50 | angle[0] = TMath::ATan(x[2]/rtotal); |
51 | angle[1]=0; | |
52 | return angle; | |
53 | } | |
54 | Float_t mtotal =TMath::Sqrt(momentum[0]*momentum[0]+momentum[1]*momentum[1]); | |
55 | if (mtotal==0) { | |
56 | angle[0]= 0; | |
57 | angle[1]=0; | |
58 | return angle; | |
59 | } | |
60 | angle[0]= TMath::ATan(momentum[2]/mtotal); | |
61 | Float_t radius1 = TMath::Sqrt(x[0]*x[0]+x[1]*x[1]); //axial symetry in z | |
62 | Float_t radius2 = 1000*mtotal/(3*fBField); | |
63 | if (radius1<radius2) | |
64 | angle[1]= TMath::ASin(radius1/radius2); | |
7d855b04 | 65 | else |
cc80f89e | 66 | angle[1]=0; |
67 | return angle; | |
7d855b04 | 68 | } |
cc80f89e | 69 | |
7d855b04 | 70 | ClassImp(AliDetectorParam); |