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f3c4a6df | 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 | ||
155f1576 | 16 | |
17 | /* | |
18 | $Log$ | |
19 | */ | |
20 | ||
f3c4a6df | 21 | |
22 | //*-- Author: Andreas Morsch (CERN) | |
23 | ||
24 | #include "AliEMCALFast.h" | |
25 | #include <TRandom.h> | |
26 | ||
27 | ||
28 | ClassImp(AliEMCALFast) | |
29 | ||
30 | //____________________________________________________________________________ | |
31 | ||
32 | ||
33 | Float_t AliEMCALFast::SmearMomentum(Int_t ind, Float_t p) | |
34 | { | |
35 | // | |
155f1576 | 36 | // The relative momentum error, i.e. |
37 | // (delta p)/p = sqrt (a**2 + (b*p)**2) * 10**-2, | |
f3c4a6df | 38 | // where typically a = 0.75 and b = 0.16 - 0.24 depending on multiplicity |
39 | // (the lower value is for dn/d(eta) about 2000, and the higher one for 8000) | |
40 | // | |
41 | Float_t pSmeared; | |
42 | Float_t a = 0.75; | |
43 | Float_t b = 0.24; | |
44 | if (ind == 2) b = 0.16; | |
45 | ||
46 | Float_t sigma = p*TMath::Sqrt(a*a+b*b*p*p)*0.01; | |
47 | pSmeared = p + gRandom->Gaus(0., sigma); | |
48 | return pSmeared; | |
49 | } | |
50 | ||
51 | ||
52 | Float_t AliEMCALFast::Efficiency(Int_t ind, Float_t p) | |
53 | { | |
54 | // Tracking efficiency: | |
155f1576 | 55 | // above pt 0.5 GeV practically constant, between 90 and 95 % (again, |
f3c4a6df | 56 | // depending on multplicity) |
57 | // below 0.5 GeV goes down to about 70% at 0.2 GeV. | |
58 | // On top of that there is 90% geometrical acceptance for tracking due | |
59 | // to TPC (dead zones between readout chambers). | |
60 | Float_t eff = 0.; | |
61 | // Tracking | |
62 | if (p > 0.5) { | |
63 | eff = 0.9; | |
64 | if (ind == 2) eff = 0.95; | |
65 | } else { | |
66 | eff = eff-(0.5-p)*0.2/0.3; | |
67 | } | |
155f1576 | 68 | eff *= 0.9; |
f3c4a6df | 69 | // Acceptance |
70 | return eff; | |
71 | } | |
72 | ||
155f1576 | 73 | Bool_t AliEMCALFast::EmcalAcceptance(Float_t eta, Float_t phi) |
74 | { | |
75 | // | |
76 | // EMCAL eta-phi acceptance | |
77 | Bool_t acc = kFALSE; | |
78 | if (TMath::Abs(eta) < 0.7 && | |
79 | phi > 0. && | |
80 | phi < 120.*TMath::Pi()/180.) | |
81 | acc = kTRUE; | |
82 | return acc; | |
83 | } | |
84 | ||
85 | ||
86 | Bool_t AliEMCALFast::RandomReject(Float_t eff) | |
87 | { | |
88 | // | |
89 | // Random rejection | |
90 | Bool_t rej = kFALSE; | |
91 | Float_t ran = gRandom->Rndm(); | |
92 | if (ran > eff) rej = kTRUE; | |
93 | return rej; | |
94 | } | |
f3c4a6df | 95 | |
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