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 | // -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/UnstableParticles.hh"
namespace Rivet {
/// @brief B -> pi,rho l+ nu
class BABAR_2011_I855306 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(BABAR_2011_I855306);
/// @name Analysis methods
/// @{
/// Book histograms and initialise projections before the run
void init() {
// Initialise and register projections
declare(UnstableParticles(Cuts::abspid==PID::BPLUS ||
Cuts::abspid==PID::B0 ), "UFS");
for(unsigned int ix=0;ix<2;++ix) {
book(_c[ix],"TMP/c_"+toString(ix+1));
for(unsigned int iy=0;iy<3;++iy) {
book(_h[ix][iy],ix+1,1,iy+1);
}
}
}
// Calculate the Q2 using mother and daughter charged lepton
double q2(const Particle& B, int mesonID) {
FourMomentum q = B.mom() - filter_select(B.children(), Cuts::pid==mesonID)[0];
return q*q;
}
// Check for explicit decay into pdgids
bool isSemileptonicDecay(const Particle& mother, vector<int> ids) {
// Trivial check to ignore any other decays but the one in question modulo photons
const Particles children = mother.children(Cuts::pid!=PID::PHOTON);
if (children.size()!=ids.size()) return false;
// Check for the explicit decay
return all(ids, [&](int i){return count(children, hasPID(i))==1;});
}
/// Perform the per-event analysis
void analyze(const Event& event) {
// Get B+ Mesons
for(const Particle& p : apply<UnstableParticles>(event, "UFS").particles()) {
// B0 modes
if(p.abspid()==511) {
_c[0]->fill();
if (isSemileptonicDecay(p, {PID::PIMINUS, PID::POSITRON, PID::NU_E}) ||
isSemileptonicDecay(p, {PID::PIMINUS, PID::ANTIMUON, PID::NU_MU}) ) {
double qq = q2(p,PID::PIMINUS);
_h[0][0]->fill(qq);
_h[0][2]->fill(qq);
}
else if(isSemileptonicDecay(p, {PID::PIPLUS , PID::ELECTRON, PID::NU_EBAR}) ||
isSemileptonicDecay(p, {PID::PIPLUS , PID::MUON , PID::NU_MUBAR})) {
double qq = q2(p,PID::PIPLUS);
_h[0][0]->fill(qq);
_h[0][2]->fill(qq);
}
else if (isSemileptonicDecay(p, {PID::RHOMINUS, PID::POSITRON, PID::NU_E}) ||
isSemileptonicDecay(p, {PID::RHOMINUS, PID::ANTIMUON, PID::NU_MU})) {
double qq = q2(p,PID::RHOMINUS);
_h[1][0]->fill(qq);
_h[1][2]->fill(qq);
}
else if( isSemileptonicDecay(p, {PID::RHOPLUS, PID::ELECTRON, PID::NU_EBAR}) ||
isSemileptonicDecay(p, {PID::RHOPLUS, PID::MUON , PID::NU_MUBAR})) {
double qq = q2(p,PID::RHOPLUS);
_h[1][0]->fill(qq);
_h[1][2]->fill(qq);
}
}
// B+ modes
else {
_c[1]->fill();
if (isSemileptonicDecay(p, {PID::PI0, PID::POSITRON, PID::NU_E}) ||
isSemileptonicDecay(p, {PID::PI0, PID::ANTIMUON, PID::NU_MU}) ||
isSemileptonicDecay(p, {PID::PI0, PID::ELECTRON, PID::NU_EBAR}) ||
isSemileptonicDecay(p, {PID::PI0, PID::MUON , PID::NU_MUBAR})) {
_h[0][1]->fill(q2(p,PID::PI0));
}
else if (isSemileptonicDecay(p, {PID::RHO0, PID::POSITRON, PID::NU_E}) ||
isSemileptonicDecay(p, {PID::RHO0, PID::ANTIMUON, PID::NU_MU}) ||
isSemileptonicDecay(p, {PID::RHO0, PID::ELECTRON, PID::NU_EBAR}) ||
isSemileptonicDecay(p, {PID::RHO0, PID::MUON , PID::NU_MUBAR})) {
_h[1][1]->fill(q2(p,PID::RHO0));
}
}
}
}
/// Normalise histograms etc., after the run
void finalize() {
// Br in units 10^-4 and average over e/mu modes
for(unsigned int ix=0;ix<2;++ix) {
for(unsigned int iy=0;iy<3;++iy) {
if(iy==1) scale(_h[ix][iy], 0.5*1e4/ *_c[1]);
else scale(_h[ix][iy], 0.5*1e4/ *_c[0]);
}
}
}
/// @}
/// @name Histograms
/// @{
Histo1DPtr _h[2][3];
CounterPtr _c[2];
/// @}
};
RIVET_DECLARE_PLUGIN(BABAR_2011_I855306);
}
|