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 | // -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/UnstableParticles.hh"
namespace Rivet {
/// @brief B -> X_u ell nu
class BABAR_2012_I1079912 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(BABAR_2012_I1079912);
/// @name Analysis methods
/// @{
/// Book histograms and initialise projections before the run
void init() {
// projections
declare(UnstableParticles(Cuts::abspid==511 or
Cuts::abspid==521),"UFS");
// histograms
book(_h,1,1,1);
book(_nB,"/TMP/nB");
}
void findDecayProducts(Particle parent, Particles & em, Particles & ep,
Particles & nue, Particles & nueBar, bool & charm) {
for(const Particle & p : parent.children()) {
if(PID::isCharmHadron(p.pid())) {
charm=true;
}
else if(p.pid() == PID::EMINUS) {
em.push_back(p);
}
else if(p.pid() == PID::EPLUS) {
ep.push_back(p);
}
else if(p.pid() == PID::NU_E || p.pid()==PID::NU_MU) {
nue.push_back(p);
}
else if(p.pid() == PID::NU_EBAR || p.pid()==PID::NU_MUBAR) {
nueBar.push_back(p);
}
else if(PID::isBottomHadron(p.pid())) {
findDecayProducts(p,em,ep,nue,nueBar,charm);
}
else if(!PID::isHadron(p.pid())) {
findDecayProducts(p,em,ep,nue,nueBar,charm);
}
}
}
/// Perform the per-event analysis
void analyze(const Event& event) {
const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
for(const Particle& p : ufs.particles()) {
if(p.children().empty()) continue;
if(p.children()[0].abspid()==p.abspid()) continue;
_nB->fill();
bool charm = false;
Particles em,ep,nue,nueBar;
findDecayProducts(p,em,ep,nue,nueBar,charm);
if(charm) continue;
FourMomentum pl,pnu;
if(em.size()==1 && nueBar.size()==1) {
pl = em[0].momentum();
}
else if(ep.size()==1 && nue.size()==1) {
pl = ep[0].momentum();
}
else
continue;
LorentzTransform boost = LorentzTransform::mkFrameTransformFromBeta(p.momentum().betaVec());
pl = boost.transform(pl );
double pp = pl.p3().mod();
for(const auto & bin : _h->bins())
if(bin.xMin()<pp) _h->fill(bin.xMid());
}
}
/// Normalise histograms etc., after the run
void finalize() {
// 1e3 due br normalization and 0.1 to remove bin width
scale(_h, 0.1*1e3/ *_nB);
}
/// @}
/// @name Histograms
/// @{
Histo1DPtr _h;
CounterPtr _nB;
/// @}
};
RIVET_DECLARE_PLUGIN(BABAR_2012_I1079912);
}
|