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BESIII Offline Software System
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BesEvtGen-00-04-08/src/EvtGen/EvtGenModels/EvtBTo4piCP.cc File Reference
#include "EvtGenBase/EvtPatches.hh"
#include <stdlib.h>
#include "EvtGenBase/EvtParticle.hh"
#include "EvtGenBase/EvtGenKine.hh"
#include "EvtGenBase/EvtCPUtil.hh"
#include "EvtGenBase/EvtPDL.hh"
#include "EvtGenBase/EvtReport.hh"
#include "EvtGenModels/EvtBTo4piCP.hh"
#include "EvtGenBase/EvtId.hh"
#include "EvtGenBase/EvtConst.hh"
#include <string>

Go to the source code of this file.

Functions

EvtComplex EvtAmpA2 (const EvtVector4R &p4pi1, const EvtVector4R &p4pi2, const EvtVector4R &p4pi3, const EvtVector4R &p4pi4)
 
EvtComplex EvtAmpA1 (const EvtVector4R &p4pi1, const EvtVector4R &p4pi2, const EvtVector4R &p4pi3, const EvtVector4R &p4pi4)
 

Function Documentation

◆ EvtAmpA1()

EvtComplex EvtAmpA1 ( const EvtVector4R p4pi1,
const EvtVector4R p4pi2,
const EvtVector4R p4pi3,
const EvtVector4R p4pi4 
)

Definition at line 95 of file BesEvtGen-00-04-08/src/EvtGen/EvtGenModels/EvtBTo4piCP.cc.

96 {
97
98 //added by Lange Jan4,2000
99 static EvtId A1M=EvtPDL::getId("a_1-");
100 static EvtId RHO0=EvtPDL::getId("rho0");
101
102 EvtVector4R p4a1,p4rho,p4b;
103
104 p4rho=p4pi1+p4pi2;
105
106 p4a1=p4rho+p4pi3;
107
108 p4b=p4a1+p4pi4;
109
110 EvtVector4R p4b_a1,p4rho_a1,p4pi1_a1,p4a1_a1;
111
112 p4b_a1=boostTo(p4b,p4a1);
113 p4rho_a1=boostTo(p4rho,p4a1);
114 p4pi1_a1=boostTo(p4pi1,p4a1);
115 p4a1_a1=boostTo(p4a1,p4a1);
116
117 EvtVector4R p4pi1_rho;
118
119 p4pi1_rho=boostTo(p4pi1_a1,p4rho_a1);
120
121 EvtVector4R vb,vrho,vpi,t;
122
123 vb=p4b_a1/p4b_a1.d3mag();
124 vrho=p4rho_a1/p4rho_a1.d3mag();
125 vpi=p4pi1_rho/p4pi1_rho.d3mag();
126
127 t.set(1.0,0.0,0.0,0.0);
128
129 EvtComplex amp_a1;
130
131 double bwm_a1=EvtPDL::getMeanMass(A1M);
132 double gamma_a1=EvtPDL::getWidth(A1M);
133 // double bwm_a2=EvtPDL::getMeanMass(A2M);
134 // double gamma_a2=EvtPDL::getWidth(A2M);
135 double bwm_rho=EvtPDL::getMeanMass(RHO0);
136 double gamma_rho=EvtPDL::getWidth(RHO0);
137
138 amp_a1=(sqrt(gamma_a1/EvtConst::twoPi)/
139 ((p4a1).mass()-bwm_a1-EvtComplex(0.0,0.5*gamma_a1)))*
140 (sqrt(gamma_rho/EvtConst::twoPi)/
141 ((p4rho).mass()-bwm_rho-EvtComplex(0.0,0.5*gamma_rho)));
142
143 return amp_a1*
144 (vb.get(1)*vpi.get(1)+vb.get(2)*vpi.get(2)+vb.get(3)*vpi.get(3));
145
146}
double mass
EvtDiracSpinor boostTo(const EvtDiracSpinor &sp, const EvtVector4R p4)
TTree * t
Definition: binning.cxx:23
static EvtId getId(const std::string &name)

◆ EvtAmpA2()

EvtComplex EvtAmpA2 ( const EvtVector4R p4pi1,
const EvtVector4R p4pi2,
const EvtVector4R p4pi3,
const EvtVector4R p4pi4 
)

Definition at line 36 of file BesEvtGen-00-04-08/src/EvtGen/EvtGenModels/EvtBTo4piCP.cc.

37 {
38
39 //added by Lange Jan4,2000
40 static EvtId A2M=EvtPDL::getId("a_2-");
41 static EvtId RHO0=EvtPDL::getId("rho0");
42
43 EvtVector4R p4a2,p4rho,p4b;
44
45 p4rho=p4pi1+p4pi2;
46
47 p4a2=p4rho+p4pi3;
48
49 p4b=p4a2+p4pi4;
50
51 EvtVector4R p4b_a2,p4rho_a2,p4pi1_a2,p4a2_a2;
52
53 p4b_a2=boostTo(p4b,p4a2);
54 p4rho_a2=boostTo(p4rho,p4a2);
55 p4pi1_a2=boostTo(p4pi1,p4a2);
56 p4a2_a2=boostTo(p4a2,p4a2);
57
58 EvtVector4R p4pi1_rho;
59
60 p4pi1_rho=boostTo(p4pi1_a2,p4rho_a2);
61
62 EvtVector4R vb,vrho,vpi,t;
63
64 vb=p4b_a2/p4b_a2.d3mag();
65 vrho=p4rho_a2/p4rho_a2.d3mag();
66 vpi=p4pi1_rho/p4pi1_rho.d3mag();
67
68 t.set(1.0,0.0,0.0,0.0);
69
70 // EvtComplex amp_a1,amp_a2;
71 EvtComplex amp_a2;
72
73 // double bwm_a1=EvtPDL::getMeanMass(A1M);
74 // double gamma_a1=EvtPDL::getWidth(A1M);
75 double bwm_a2=EvtPDL::getMeanMass(A2M);
76 double gamma_a2=EvtPDL::getWidth(A2M);
77 double bwm_rho=EvtPDL::getMeanMass(RHO0);
78 double gamma_rho=EvtPDL::getWidth(RHO0);
79
80 amp_a2=(sqrt(gamma_a2/EvtConst::twoPi)/
81 ((p4a2).mass()-bwm_a2-EvtComplex(0.0,0.5*gamma_a2)))*
82 (sqrt(gamma_rho/EvtConst::twoPi)/
83 ((p4rho).mass()-bwm_rho-EvtComplex(0.0,0.5*gamma_rho)));
84
85 return amp_a2*
86 (vb.get(1)*vrho.get(1)+vb.get(2)*vrho.get(2)+vb.get(3)*vrho.get(3))*
87 (
88 vpi.get(1)*(vb.get(2)*vrho.get(3)-vb.get(3)*vrho.get(2))+
89 vpi.get(2)*(vb.get(3)*vrho.get(1)-vb.get(1)*vrho.get(3))+
90 vpi.get(3)*(vb.get(1)*vrho.get(2)-vb.get(2)*vrho.get(1))
91 );
92
93}