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. *
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8 * documentation strictly for non-commercial purposes is hereby granted *
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11 * appear in the supporting documentation. The authors make no claims *
12 * about the suitability of this software for any purpose. It is *
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14 **************************************************************************/
18 // -----------------------
19 // Class AliMUONMathieson
20 // -----------------------
21 // Implementation of Mathieson response
22 // Separated from other classes by CH. Finck with removing circular
25 #include "AliMUONMathieson.h"
28 #include "AliMUONGeometrySegmentation.h"
34 ClassImp(AliMUONMathieson)
36 //__________________________________________________________________________
37 AliMUONMathieson::AliMUONMathieson() :
47 /// Default constructor
51 //__________________________________________________________________________
52 void AliMUONMathieson::SetSqrtKx3AndDeriveKx2Kx4(Float_t SqrtKx3)
54 /// Set to "SqrtKx3" the Mathieson parameter K3 ("fSqrtKx3")
55 /// in the X direction, perpendicular to the wires,
56 /// and derive the Mathieson parameters K2 ("fKx2") and K4 ("fKx4")
57 /// in the same direction
59 fKx2 = TMath::Pi() / 2. * (1. - 0.5 * fSqrtKx3);
60 Float_t cx1 = fKx2 * fSqrtKx3 / 4. / TMath::ATan(Double_t(fSqrtKx3));
61 fKx4 = cx1 / fKx2 / fSqrtKx3;
64 //__________________________________________________________________________
65 void AliMUONMathieson::SetSqrtKy3AndDeriveKy2Ky4(Float_t SqrtKy3)
67 /// Set to "SqrtKy3" the Mathieson parameter K3 ("fSqrtKy3")
68 /// in the Y direction, along the wires,
69 /// and derive the Mathieson parameters K2 ("fKy2") and K4 ("fKy4")
70 /// in the same direction
72 fKy2 = TMath::Pi() / 2. * (1. - 0.5 * fSqrtKy3);
73 Float_t cy1 = fKy2 * fSqrtKy3 / 4. / TMath::ATan(Double_t(fSqrtKy3));
74 fKy4 = cy1 / fKy2 / fSqrtKy3;
77 //_____________________________________________________________________________
79 AliMUONMathieson::IntXY(Float_t xi1, Float_t yi1, Float_t xi2, Float_t yi2) const
81 /// Integrate the Mathieson over x and y
88 // The Mathieson function
89 Double_t ux1=fSqrtKx3*TMath::TanH(fKx2*xi1);
90 Double_t ux2=fSqrtKx3*TMath::TanH(fKx2*xi2);
92 Double_t uy1=fSqrtKy3*TMath::TanH(fKy2*yi1);
93 Double_t uy2=fSqrtKy3*TMath::TanH(fKy2*yi2);
96 return Float_t(4.*fKx4*(TMath::ATan(ux2)-TMath::ATan(ux1))*
97 fKy4*(TMath::ATan(uy2)-TMath::ATan(uy1)));
100 // -------------------------------------------
101 Float_t AliMUONMathieson::IntXY(Int_t idDE, AliMUONGeometrySegmentation* segmentation) const
103 /// Calculate charge on current pad according to Mathieson distribution
104 /// using Detection elt
106 // Integration limits defined by segmentation model
108 Float_t xi1, xi2, yi1, yi2;
109 segmentation->IntegrationLimits(idDE, xi1,xi2,yi1,yi2);
110 return IntXY(xi1,yi1,xi2,yi2);
113 //______________________________________________________________________________
115 AliMUONMathieson::SetPitch(Float_t p1)
117 /// Defines the pitch, and store its inverse, which is what is used in fact.
122 fInversePitch = 1/fPitch;
126 AliError(Form("Invalid pitch %e",p1));