|
|
Rivet analyses reference
BABAR_2021_I1844422
Cross sections for $e^+e^-\to 2\pi^+2\pi^-3\pi^0$ and $2\pi^+2\pi^-2\pi^0\eta$ from threshold to 4.5 GeV
Experiment: BABAR (PEP-II)
Inspire ID: 1844422
Status: VALIDATED
Authors:
References:
Beams: e+ e-
Beam energies: ANY
Run details:
Measurement of the cross sections for $e^+e^-\to 2\pi^+2\pi^-3\pi^0$ and $2\pi^+2\pi^-2\pi^0\eta$ from threshold to 4.5 GeV by BaBar. The $2\pi^+2\pi^-\eta$, $\omega\pi^0\eta$, $\pi^+\pi^-2\pi^0\omega$, $\pi^+\pi^-2\pi^0\eta$ resonant subprocesses are also measured.
Source code:
BABAR_2021_I1844422.cc
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183 | // -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/FinalState.hh"
#include "Rivet/Projections/UnstableParticles.hh"
namespace Rivet {
/// @brief e+e- > 2pi+ 2pi- 3pi0 and 2pi+ 2pi- 2pi0 eta
class BABAR_2021_I1844422 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(BABAR_2021_I1844422);
/// @name Analysis methods
///@{
/// Book histograms and initialise projections before the run
void init() {
// Initialise and register projections
declare(FinalState(), "FS");
declare(UnstableParticles(), "UFS");
book(_c_2pip2pim3pi0 ,"TMP/2pip2pim3pi0" );
book(_c_2pip2pimeta ,"TMP/2pip2pimeta" );
book(_c_omegapi0eta ,"TMP/omegapi0eta" );
book(_c_pippim2pi0omega,"TMP/pippim2pi0omega");
book(_c_pippim2pi0eta ,"TMP/pippim2pi0eta" );
book(_c_2pip2pim2pi0eta,"TMP/2pip2pim2pi0eta");
}
void findChildren(const Particle & p,map<long,int> & nRes, int &ncount) {
for(const Particle &child : p.children()) {
if(child.children().empty()) {
--nRes[child.pid()];
--ncount;
}
else
findChildren(child,nRes,ncount);
}
}
/// Perform the per-event analysis
void analyze(const Event& event) {
const FinalState& fs = apply<FinalState>(event, "FS");
map<long,int> nCount;
int ntotal(0);
for (const Particle& p : fs.particles()) {
nCount[p.pid()] += 1;
++ntotal;
}
if(ntotal==7 && nCount[211]==2 && nCount[-211]==2 && nCount[111]==3)
_c_2pip2pim3pi0->fill();
// intermediate omega and eta mesons
Particles unstable = apply<FinalState>(event, "UFS").particles(Cuts::pid==223 or Cuts::pid==221);
for (const Particle& p : unstable) {
if(p.children().empty()) continue;
map<long,int> nRes = nCount;
int ncount = ntotal;
findChildren(p,nRes,ncount);
// eta
if(p.pid()==221) {
if(ncount==4) {
// 2pi+2pi- eta
if(nRes[211]==2 && nRes[-211]==2 ) {
_c_2pip2pimeta->fill();
}
// pi+pi- 2pi0 eta
else if(nRes[211]==1 && nRes[-211]==1 && nRes[111]==2 ) {
_c_pippim2pi0eta->fill();
}
}
else if(ncount==6) {
// 2pi+ 2pi- 2pi0 eta
if(nRes[211]==2 && nRes[-211]==2 && nRes[111]==2 ) {
_c_2pip2pim2pi0eta->fill();
}
}
}
// omega
else if(p.pid()==223) {
// pi+pi- 2pi0 omega
if(ncount==4 && nRes[211]==1 && nRes[-211]==1 && nRes[111]==2 ) {
_c_pippim2pi0omega->fill();
}
}
// mode with both eta and omega
// pi0 omega eta
for (const Particle& p2 : unstable ) {
if(p2.pid()==p.pid()) continue;
map<long,int> nResB = nRes;
int ncountB = ncount;
findChildren(p2,nResB,ncountB);
if(ncountB!=1) continue;
bool matched = true;
for(auto const & val : nResB) {
if(abs(val.first)==111) {
if(val.second !=1) {
matched = false;
break;
}
}
else if(val.second!=0) {
matched = false;
break;
}
}
if(matched) {
_c_omegapi0eta->fill();
break;
}
}
}
}
/// Normalise histograms etc., after the run
void finalize() {
for(unsigned int ix=1;ix<7;++ix) {
double sigma = 0., error = 0.;
if(ix==1) {
sigma = _c_2pip2pim3pi0->val();
error = _c_2pip2pim3pi0->err();
}
else if(ix==2) {
sigma = _c_2pip2pimeta->val();
error = _c_2pip2pimeta->err();
}
else if(ix==3) {
sigma = _c_omegapi0eta->val();
error = _c_omegapi0eta->err();
}
else if(ix==4) {
sigma = _c_pippim2pi0omega->val();
error = _c_pippim2pi0omega->err();
}
else if(ix==5) {
sigma = _c_pippim2pi0eta->val();
error = _c_pippim2pi0eta->err();
}
else if(ix==6) {
sigma = _c_2pip2pim2pi0eta->val();
error = _c_2pip2pim2pi0eta->err();
}
sigma *= crossSection()/ sumOfWeights() /nanobarn;
error *= crossSection()/ sumOfWeights() /nanobarn;
Scatter2D temphisto(refData(ix, 1, 1));
Scatter2DPtr mult;
book(mult, ix, 1, 1);
for (size_t b = 0; b < temphisto.numPoints(); b++) {
const double x = temphisto.point(b).x();
pair<double,double> ex = temphisto.point(b).xErrs();
pair<double,double> ex2 = ex;
if(ex2.first ==0.) ex2. first=0.0001;
if(ex2.second==0.) ex2.second=0.0001;
if (inRange(sqrtS()/GeV, x-ex2.first, x+ex2.second)) {
mult->addPoint(x, sigma, ex, make_pair(error,error));
}
else {
mult->addPoint(x, 0., ex, make_pair(0.,.0));
}
}
}
}
///@}
/// @name Histograms
///@{
CounterPtr _c_2pip2pim3pi0, _c_2pip2pimeta, _c_omegapi0eta,
_c_pippim2pi0omega, _c_pippim2pi0eta, _c_2pip2pim2pi0eta;
///@}
};
RIVET_DECLARE_PLUGIN(BABAR_2021_I1844422);
}
|
|