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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 | |
803d1ab0 | 17 | /* $Id$ */ |
f3c4a6df | 18 | |
19 | //*-- Author: Andreas Morsch (CERN) | |
20 | ||
d64c959b | 21 | #include "TMath.h" |
f3c4a6df | 22 | #include <TRandom.h> |
23 | ||
d64c959b | 24 | #include "AliEMCALFast.h" |
25 | ||
f3c4a6df | 26 | |
27 | ClassImp(AliEMCALFast) | |
28 | ||
29 | //____________________________________________________________________________ | |
30 | ||
31 | ||
32 | Float_t AliEMCALFast::SmearMomentum(Int_t ind, Float_t p) | |
33 | { | |
34 | // | |
155f1576 | 35 | // The relative momentum error, i.e. |
36 | // (delta p)/p = sqrt (a**2 + (b*p)**2) * 10**-2, | |
f3c4a6df | 37 | // where typically a = 0.75 and b = 0.16 - 0.24 depending on multiplicity |
38 | // (the lower value is for dn/d(eta) about 2000, and the higher one for 8000) | |
39 | // | |
33e0ecee | 40 | // If we include information from TRD b will be by a factor 2/3 smaller. |
41 | // | |
42 | // ind = 1: high multiplicity | |
43 | // ind = 2: low multiplicity | |
44 | // ind = 3: high multiplicity + TRD | |
45 | // ind = 4: low multiplicity + TRD | |
46 | ||
f3c4a6df | 47 | Float_t pSmeared; |
48 | Float_t a = 0.75; | |
49 | Float_t b = 0.24; | |
33e0ecee | 50 | |
51 | if (ind == 1) b = 0.24; | |
f3c4a6df | 52 | if (ind == 2) b = 0.16; |
33e0ecee | 53 | if (ind == 3) b = 0.16; |
54 | if (ind == 4) b = 0.11; | |
f3c4a6df | 55 | |
56 | Float_t sigma = p*TMath::Sqrt(a*a+b*b*p*p)*0.01; | |
57 | pSmeared = p + gRandom->Gaus(0., sigma); | |
58 | return pSmeared; | |
59 | } | |
60 | ||
61 | ||
62 | Float_t AliEMCALFast::Efficiency(Int_t ind, Float_t p) | |
63 | { | |
64 | // Tracking efficiency: | |
155f1576 | 65 | // above pt 0.5 GeV practically constant, between 90 and 95 % (again, |
f3c4a6df | 66 | // depending on multplicity) |
67 | // below 0.5 GeV goes down to about 70% at 0.2 GeV. | |
68 | // On top of that there is 90% geometrical acceptance for tracking due | |
69 | // to TPC (dead zones between readout chambers). | |
f3c4a6df | 70 | // Tracking |
b03ac336 | 71 | // |
72 | Float_t eff = 0.9; | |
73 | if (ind == 2) eff = 0.95; | |
74 | if (p < 0.5) eff -= (0.5-p)*0.2/0.3; | |
75 | // Geometry | |
155f1576 | 76 | eff *= 0.9; |
f3c4a6df | 77 | // Acceptance |
78 | return eff; | |
79 | } | |
80 | ||
155f1576 | 81 | Bool_t AliEMCALFast::EmcalAcceptance(Float_t eta, Float_t phi) |
82 | { | |
83 | // | |
84 | // EMCAL eta-phi acceptance | |
85 | Bool_t acc = kFALSE; | |
86 | if (TMath::Abs(eta) < 0.7 && | |
adb5ffcb | 87 | phi > 60.*TMath::Pi()/180. && |
88 | phi < TMath::Pi()) | |
155f1576 | 89 | acc = kTRUE; |
90 | return acc; | |
91 | } | |
92 | ||
93 | ||
94 | Bool_t AliEMCALFast::RandomReject(Float_t eff) | |
95 | { | |
96 | // | |
97 | // Random rejection | |
98 | Bool_t rej = kFALSE; | |
99 | Float_t ran = gRandom->Rndm(); | |
100 | if (ran > eff) rej = kTRUE; | |
101 | return rej; | |
102 | } | |
f3c4a6df | 103 | |
104 | ||
105 | ||
106 | ||
107 | ||
108 | ||
109 |