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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 | ||
21 | #include "AliEMCALFast.h" | |
22 | #include <TRandom.h> | |
23 | ||
24 | ||
25 | ClassImp(AliEMCALFast) | |
26 | ||
27 | //____________________________________________________________________________ | |
28 | ||
29 | ||
30 | Float_t AliEMCALFast::SmearMomentum(Int_t ind, Float_t p) | |
31 | { | |
32 | // | |
155f1576 | 33 | // The relative momentum error, i.e. |
34 | // (delta p)/p = sqrt (a**2 + (b*p)**2) * 10**-2, | |
f3c4a6df | 35 | // where typically a = 0.75 and b = 0.16 - 0.24 depending on multiplicity |
36 | // (the lower value is for dn/d(eta) about 2000, and the higher one for 8000) | |
37 | // | |
33e0ecee | 38 | // If we include information from TRD b will be by a factor 2/3 smaller. |
39 | // | |
40 | // ind = 1: high multiplicity | |
41 | // ind = 2: low multiplicity | |
42 | // ind = 3: high multiplicity + TRD | |
43 | // ind = 4: low multiplicity + TRD | |
44 | ||
f3c4a6df | 45 | Float_t pSmeared; |
46 | Float_t a = 0.75; | |
47 | Float_t b = 0.24; | |
33e0ecee | 48 | |
49 | if (ind == 1) b = 0.24; | |
f3c4a6df | 50 | if (ind == 2) b = 0.16; |
33e0ecee | 51 | if (ind == 3) b = 0.16; |
52 | if (ind == 4) b = 0.11; | |
f3c4a6df | 53 | |
54 | Float_t sigma = p*TMath::Sqrt(a*a+b*b*p*p)*0.01; | |
55 | pSmeared = p + gRandom->Gaus(0., sigma); | |
56 | return pSmeared; | |
57 | } | |
58 | ||
59 | ||
60 | Float_t AliEMCALFast::Efficiency(Int_t ind, Float_t p) | |
61 | { | |
62 | // Tracking efficiency: | |
155f1576 | 63 | // above pt 0.5 GeV practically constant, between 90 and 95 % (again, |
f3c4a6df | 64 | // depending on multplicity) |
65 | // below 0.5 GeV goes down to about 70% at 0.2 GeV. | |
66 | // On top of that there is 90% geometrical acceptance for tracking due | |
67 | // to TPC (dead zones between readout chambers). | |
f3c4a6df | 68 | // Tracking |
b03ac336 | 69 | // |
70 | Float_t eff = 0.9; | |
71 | if (ind == 2) eff = 0.95; | |
72 | if (p < 0.5) eff -= (0.5-p)*0.2/0.3; | |
73 | // Geometry | |
155f1576 | 74 | eff *= 0.9; |
f3c4a6df | 75 | // Acceptance |
76 | return eff; | |
77 | } | |
78 | ||
155f1576 | 79 | Bool_t AliEMCALFast::EmcalAcceptance(Float_t eta, Float_t phi) |
80 | { | |
81 | // | |
82 | // EMCAL eta-phi acceptance | |
83 | Bool_t acc = kFALSE; | |
84 | if (TMath::Abs(eta) < 0.7 && | |
85 | phi > 0. && | |
86 | phi < 120.*TMath::Pi()/180.) | |
87 | acc = kTRUE; | |
88 | return acc; | |
89 | } | |
90 | ||
91 | ||
92 | Bool_t AliEMCALFast::RandomReject(Float_t eff) | |
93 | { | |
94 | // | |
95 | // Random rejection | |
96 | Bool_t rej = kFALSE; | |
97 | Float_t ran = gRandom->Rndm(); | |
98 | if (ran > eff) rej = kTRUE; | |
99 | return rej; | |
100 | } | |
f3c4a6df | 101 | |
102 | ||
103 | ||
104 | ||
105 | ||
106 | ||
107 |