Rivet analyses referenceBELLE_2005_I667959Mass distributions and helicity angles in B+→K+π+π− and B+→K+K+K−Experiment: BELLE (KEKB) Inspire ID: 667959 Status: VALIDATED NOHEPDATA Authors:
Beam energies: ANY Run details:
Measurement of Mass distributions and helicity angles in B+→K+π+π− and B+→K+K+K− decays. The data were read from the figures in the paper and the backgrounds given subtracted. Source code: BELLE_2005_I667959.cc 1// -*- C++ -*-
2#include "Rivet/Analysis.hh"
3#include "Rivet/Projections/UnstableParticles.hh"
4#include "Rivet/Projections/DecayedParticles.hh"
5
6namespace Rivet {
7
8
9 /// @brief B -> K pi pi K K K
10 class BELLE_2005_I667959 : public Analysis {
11 public:
12
13 /// Constructor
14 RIVET_DEFAULT_ANALYSIS_CTOR(BELLE_2005_I667959);
15
16
17 /// @name Analysis methods
18 /// @{
19
20 /// Book histograms and initialise projections before the run
21 void init() {
22 UnstableParticles ufs = UnstableParticles(Cuts::abspid==521);
23 declare(ufs, "UFS");
24 DecayedParticles BP(ufs);
25 BP.addStable(PID::PI0);
26 BP.addStable(PID::K0S);
27 BP.addStable(PID::ETA);
28 BP.addStable(PID::ETAPRIME);
29 declare(BP, "BP");
30 vector<double> bins = {0.,5.,10.,15.,20.,30.};
31 vector<double> bins2 = {0.,1.05,5.,10.,30.};
32 // histos
33 for (unsigned int ix=0; ix<2; ++ix) {
34 book(_h_mass3[ix], 2, 1, 1+ix);
35 book(_h_mass2[0][ix],bins);
36 if (ix==0) book(_h_mass2[1][ix],bins );
37 else book(_h_mass2[1][ix],bins2);
38 for(unsigned int iy=0; iy<3; ++iy) {
39 book(_h_mass[ix][iy],1+4*ix,1,1+iy);
40 if (iy==2) continue;
41 book(_h_mass_zoom[ix][iy],1+4*ix,2,1+iy);
42 }
43 for(unsigned int iz=0;iz<5;++iz) {
44 book(_h_mass2[0][ix]->bin(1+iz),3,1+ix,1+iz);
45 if (ix==1 &&iz==4) continue;
46 book(_h_mass2[1][ix]->bin(iz+1),6,1+ix,1+iz);
47 }
48 }
49 for (unsigned int ix=0;ix<3;++ix) {
50 vector<double> bins3;
51 if (ix==0) bins3 = {0.82,0.97,1.,1.76};
52 else if (ix==1) bins3 = {0.,0.9,1.06};
53 else if (ix==2) bins3 = {0.,1.05,3.0};
54 book(_h_angle[ix],bins3);
55 for (unsigned int iy=0; iy<2; ++iy) {
56 if (ix==0) book(_h_angle[ix]->bin(2*iy+1),4,1,1+iy);
57 else if (ix==1) book(_h_angle[ix]->bin(iy+1) ,4,1,3+iy);
58 else if (ix==2) book(_h_angle[ix]->bin(iy+1) ,7,1,1+iy);
59 }
60 }
61 }
62
63
64 /// Perform the per-event analysis
65 void analyze(const Event& event) {
66 static const double mD0 = 1.86484, mJpsi = 3.096916, mPsi2S=3.6861;
67 DecayedParticles BP = apply<DecayedParticles>(event, "BP");
68 // loop over particles
69 for (unsigned int ix=0; ix<BP.decaying().size(); ++ix) {
70 int sign=BP.decaying()[ix].pid()/BP.decaying()[ix].abspid();
71 // boost to B rest frame
72 LorentzTransform boost =
73 LorentzTransform::mkFrameTransformFromBeta(BP.decaying()[ix]. mom().betaVec());
74 if (BP.modeMatches(ix,3,mode1) || BP.modeMatches(ix,3,mode1CC)) {
75 const Particle & Kp = BP.decayProducts()[ix].at( sign*321)[0];
76 const Particle & pip = BP.decayProducts()[ix].at( sign*211)[0];
77 const Particle & pim = BP.decayProducts()[ix].at(-sign*211)[0];
78 FourMomentum pKpi = Kp.mom() +pim.mom();
79 double mKpi = pKpi.mass();
80 if (abs(mKpi -mD0)<0.1 ) continue;
81 FourMomentum ppipi = pip.mom()+pim.mom();
82 double mpipi = ppipi.mass();
83 if (abs(mpipi -mD0)<0.015 || abs(mpipi-mJpsi)<0.07 || abs(mpipi-mPsi2S)<0.05) continue;
84 _h_mass[0][0]->fill(mKpi);
85 _h_mass[0][1]->fill(mpipi);
86 _h_mass[0][2]->fill((Kp.mom()+pip.mom()).mass());
87 _h_mass_zoom[0][0]->fill(mKpi);
88 _h_mass_zoom[0][1]->fill(mpipi);
89 if (sqr(mpipi)<11.) _h_mass3[0]->fill(mKpi);
90 else _h_mass3[1]->fill(mKpi);
91 _h_mass2[0][0]->fill(sqr(mpipi),mKpi );
92 _h_mass2[0][1]->fill(sqr(mKpi ),mpipi);
93 // helicity angles
94 // Kpi
95 pKpi = boost.transform(pKpi);
96 LorentzTransform boost2 = LorentzTransform::mkFrameTransformFromBeta(pKpi.betaVec());
97 FourMomentum ppi = boost2.transform(boost.transform(pim.mom()));
98 const double cK = ppi.p3().unit().dot(pKpi.p3().unit());
99 _h_angle[0]->fill(mKpi,cK);
100 // pi pi
101 ppipi = boost.transform(ppipi);
102 LorentzTransform boost3 = LorentzTransform::mkFrameTransformFromBeta(ppipi.betaVec());
103 ppi = boost3.transform(boost.transform(pim.mom()));
104 const double cPi = ppi.p3().unit().dot(ppipi.p3().unit());
105 _h_angle[1]->fill(mpipi,cPi);
106 }
107 else if (BP.modeMatches(ix,3,mode2) || BP.modeMatches(ix,3,mode2CC)) {
108 const Particles& Kp = BP.decayProducts()[ix].at( sign*321);
109 const Particle & Km = BP.decayProducts()[ix].at(-sign*321)[0];
110 FourMomentum pKK[2] = {Kp[0].mom()+Km.mom(), Kp[1].mom()+Km.mom()};
111 double mKK[2] = {pKK[0].mass(),pKK[1].mass()};
112 if (mKK[0]>mKK[1]) {
113 swap(mKK[0],mKK[1]);
114 swap(pKK[0],pKK[1]);
115 }
116 _h_mass[1][0]->fill(mKK[0]);
117 _h_mass[1][1]->fill(mKK[1]);
118 _h_mass[1][2]->fill((Kp[0].mom()+Kp[1].mom()).mass());
119 _h_mass_zoom[1][0]->fill(mKK[0]);
120 _h_mass_zoom[1][1]->fill(mKK[1]);
121 _h_mass2[1][0]->fill(sqr(mKK[1]),mKK[0]);
122 _h_mass2[1][1]->fill(sqr(mKK[0]),mKK[1]);
123 // helicity angles
124 // Kpi
125 pKK[0] = boost.transform(pKK[0]);
126 LorentzTransform boost2 = LorentzTransform::mkFrameTransformFromBeta(pKK[0].betaVec());
127 FourMomentum pK = boost2.transform(boost.transform(Km.mom()));
128 double cK = pK.p3().unit().dot(pKK[0].p3().unit());
129 _h_angle[2]->fill(mKK[0],cK);
130 }
131 }
132 }
133
134
135 /// Normalise histograms etc., after the run
136 void finalize() {
137 for (unsigned int ix=0; ix<2; ++ix) {
138 normalize(_h_mass3[ix], 1.0, false);
139 normalize(_h_mass[ix], 1.0, false);
140 normalize(_h_mass_zoom[ix], 1.0, false);
141 normalize(_h_mass2[ix], 1.0, false);
142 }
143 normalize(_h_angle, 1.0, false);
144 }
145
146 /// @}
147
148
149 /// @name Histograms
150 /// @{
151 Histo1DPtr _h_mass[2][3],_h_mass_zoom[2][2],_h_mass3[2];
152 Histo1DGroupPtr _h_mass2[2][2],_h_angle[3];
153 const map<PdgId,unsigned int> mode1 = { { 321,1}, { 211,1}, {-211,1} };
154 const map<PdgId,unsigned int> mode1CC = { {-321,1}, { 211,1}, {-211,1} };
155 const map<PdgId,unsigned int> mode2 = { { 321,2}, {-321,1} };
156 const map<PdgId,unsigned int> mode2CC = { {-321,2}, { 321,1} };
157 /// @}
158
159
160 };
161
162
163 RIVET_DECLARE_PLUGIN(BELLE_2005_I667959);
164
165}
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