BOSS 6.6.4.p01
BESIII Offline Software System
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EvtDIY.cc
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1//--------------------------------------------------------------------------
2//
3// Environment:
4// This software is part of models developed at BES collaboration
5// based on the EvtGen framework. If you use all or part
6// of it, please give an appropriate acknowledgement.
7//
8// Copyright Information: See EvtGen/BesCopyright
9// Copyright (A) 2006 Ping Rong-Gang @IHEP
10//
11// Module: EvtDIY.cc
12//
13// Description: Model provided by user, see the mannual
14//
15// Modification history:
16//
17// Ping R.-G. December, 2006 Module created
18//
19//------------------------------------------------------------------------
20
22#include <stdlib.h>
25#include "EvtGenBase/EvtPDL.hh"
41#include <string>
42using namespace std; //::endl;
43
45
46void EvtDIY::getName(std::string& model_name){
47
48 model_name="DIY";
49
50}
51
53
54 return new EvtDIY;
55
56}
57
58
60
61// check that there are 1 arguments:angular distribution parameter
62// checkNArg(0);
63// checkNDaug(2);
65// if ( parenttype == EvtSpinType::SCALAR ){
66// report(ERROR,"EvtGen")<<"Scalar decays with flat distribution"<<endl;
67// ::abort();
68// }
69}
71 noProbMax();
72
73}
74
75
76static int nrun=1;
77static double max_amps=0.0;
78
80
81double amps,SamAmps,rd1;
82// calculated the max amplitude square in 20000 events, is it enough larger?
83 if(nrun==1){
84 int ir,nd;
85 for(ir=0;ir<=200000;ir++){
86 loop0:
88 int nd=p->getNDaug(),i;
89 _nd=nd;
90 for(i=0;i<=nd-1;i++){
91 _p4Lab[i]=p->getDaug(i)->getP4Lab();
92 _p4CM[i]=p->getDaug(i)->getP4();
93 }
94 amps=AmplitudeSquare();
95 if(amps<0) goto loop0;
96 if(amps>max_amps) max_amps=amps*1.01;
97 nrun++;
98 }
99 }
100if(max_amps==0.0) {report(ERROR,"EvtGen")<<"The decay amplitude square should be positive number"<<endl;abort();}
101//cout<<"max_amp="<<max_amps<<endl;
102
103
104loop:
106 int i;
107 for(i=0;i<=p->getNDaug()-1;i++){
108 _p4Lab[i]=p->getDaug(i)->getP4Lab();
109 _p4CM[i]=p->getDaug(i)->getP4();
110 }
111// Put phase space results into the daughters.
112 amps=AmplitudeSquare();
113 if(amps < 0) goto loop;
114 SamAmps=amps/max_amps;
115 rd1=EvtRandom::Flat(0.0, 1.0);
116 if(rd1>=SamAmps) goto loop;
117 return ;
118}
119
120
ostream & report(Severity severity, const char *facility)
Definition: EvtReport.cc:36
@ ERROR
Definition: EvtReport.hh:49
void initProbMax()
Definition: EvtDIY.cc:70
void getName(std::string &name)
Definition: EvtDIY.cc:46
double AmplitudeSquare()
Definition: UserDIY.cc:176
virtual ~EvtDIY()
Definition: EvtDIY.cc:44
EvtDecayBase * clone()
Definition: EvtDIY.cc:52
void init()
Definition: EvtDIY.cc:59
EvtDIY()
Definition: EvtDIY.hh:33
void decay(EvtParticle *p)
Definition: EvtDIY.cc:79
void noProbMax()
EvtId getParentId()
Definition: EvtDecayBase.hh:60
EvtId * getDaugs()
Definition: EvtDecayBase.hh:65
static EvtSpinType::spintype getSpinType(EvtId i)
Definition: EvtPDL.hh:61
EvtVector4R getP4Lab()
Definition: EvtParticle.cc:683
const EvtVector4R & getP4() const
Definition: EvtParticle.cc:121
int getNDaug() const
Definition: EvtParticle.cc:125
EvtParticle * getDaug(int i)
Definition: EvtParticle.cc:85
double initializePhaseSpace(int numdaughter, EvtId *daughters, double poleSize=-1., int whichTwo1=0, int whichTwo2=1)
static double Flat()
Definition: EvtRandom.cc:73