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. *
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 **************************************************************************/
18 Revision 1.1 2002/03/11 10:56:06 morsch
19 AliGenThetaSlice, first commit. (Jiri Chudoba)
22 ////////////////////////////////////////////////////////////////////////
24 // generates n particles with in the same phi angle, varies theta
25 // in equidistant intervals
26 // This class is intended to use for studies of TPC response
27 // via merging with background event.
29 // Note that for a given theta pt and p are not independent
30 // Range for only one variable (pt or p) should be given.
31 // Based on the AliGenBox class written by andreas.morsch@cern.ch
33 // Comments and suggestions: Jiri.Chudoba@cern.ch
35 ////////////////////////////////////////////////////////////////////////
40 #include "AliGenThetaSlice.h"
43 ClassImp(AliGenThetaSlice)
45 //_____________________________________________________________________________
46 AliGenThetaSlice::AliGenThetaSlice()
50 // Default constructor
55 //_____________________________________________________________________________
56 AliGenThetaSlice::AliGenThetaSlice(Int_t npart)
60 // Standard constructor
63 fTitle = "Particle generator - const. phi, slices in theta";
64 // Generate Proton by default
68 //_____________________________________________________________________________
70 void AliGenThetaSlice::Generate()
73 // Generate one trigger
76 Float_t polar[3]= {0,0,0};
80 Double_t pmom, theta, phi, pt;
83 if (fNpart == 0) return;
85 for (j=0;j<3;j++) origin[j]=fOrigin[j];
86 if(fVertexSmear==kPerEvent) {
89 origin[j]+=fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
90 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
93 Float_t thetaInterval = 0.;
95 thetaInterval = (fThetaMax-fThetaMin)/(fNpart-1);
98 phi=fPhiMin+random[0]*(fPhiMax-fPhiMin);
99 for(i=0;i<fNpart;i++) {
101 theta=fThetaMin+i*thetaInterval;
102 if(TestBit(kMomentumRange)) {
103 pmom=fPMin+random[0]*(fPMax-fPMin);
104 pt=pmom*TMath::Sin(theta);
106 pt=fPtMin+random[0]*(fPtMax-fPtMin);
107 pmom=pt/TMath::Sin(theta);
109 p[0] = pt*TMath::Cos(phi);
110 p[1] = pt*TMath::Sin(phi);
111 p[2] = pmom*TMath::Cos(theta);
113 if(fVertexSmear==kPerTrack) {
116 origin[j]=fOrigin[j]+fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
117 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
120 SetTrack(fTrackIt,-1,fIpart,p,origin,polar,0,kPPrimary,nt);
124 //_____________________________________________________________________________
126 void AliGenThetaSlice::Init()
128 // Initialisation, check consistency of selected ranges
129 if(TestBit(kPtRange)&&TestBit(kMomentumRange))
130 Fatal("Init","You should not set the momentum range and the pt range!\n");
131 if((!TestBit(kPtRange))&&(!TestBit(kMomentumRange)))
132 Fatal("Init","You should set either the momentum or the pt range!\n");