Rivet analyses
title: BELLE_2016_I1408873
$\chi_{c1}$ and $\chi_{c2}$ production in $B$ decays
Experiment: BELLE (KEKB)
Inspire ID: 1408873
Status: VALIDATED NOHEPDATA
Authors: - Peter Richardson
References: - Phys.Rev.D 93 (2016) 5, 052016
Beams: e+ e-
Beam energies: (5.3, 5.3)GeV
Run details: - $e^+ e^-$ at the $\Upsilon(4S)$
Measurement of inclusve production of $\chi_{c1}$ and $\chi_{c2}$ in $B$ decays, in reality the spectrum at the $\Upsilon(4S)$, together with mass distributions in several $B$ decays.
Source code:BELLE_2016_I1408873.cc
```c++ // -- C++ --
include "Rivet/Analysis.hh"
include "Rivet/Projections/DecayedParticles.hh"
include "Rivet/Projections/UnstableParticles.hh"
namespace Rivet {
/// @brief B -> chi_c1 and chi_c2 class BELLE_2016_I1408873 : public Analysis { public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(BELLE_2016_I1408873);
/// @name Analysis methods
/// @{
/// Book histograms and initialise projections before the run
void init() {
// projections
declare(UnstableParticles(Cuts::pid == 300553 or Cuts::pid == 9000553), "UPS");
UnstableParticles ufs = UnstableParticles(Cuts::abspid == 511 || Cuts::abspid == 521);
declare(ufs, "UFS");
DecayedParticles BB(ufs);
BB.addStable(20443);
BB.addStable(445);
BB.addStable(310);
BB.addStable(111);
declare(BB, "BB");
// book histograms
for (unsigned int ix = 0; ix < 2; ++ix) {
book(_h_spect[ix], 1, 1, 1 + ix);
for (int iy = 0; iy < 5; ++iy) {
book(_h_three[iy][ix], 2, 1 + ix, 1 + iy);
if (iy < 2)
book(_h_four[ix][iy], 3, 1 + iy, 1 + ix);
else
book(_h_four[ix][iy], 4, iy - 1, 1 + ix);
}
}
book(_wUps, "/TMP/Ups4");
}
/// Recursively walk the decay tree to find decay products of @a p
void findDecayProducts(Particle mother, Particles& unstable) {
for (const Particle& p : mother.children()) {
const int id = abs(p.pid());
if (id == 20443 || id == 445) {
unstable.push_back(p);
}
else if (!p.children().empty())
findDecayProducts(p, unstable);
}
}
/// Perform the per-event analysis
void analyze(const Event& event) {
// upsilon spectrum
for (const Particle& ups : apply<UnstableParticles>(event, "UPS").particles()) {
_wUps->fill();
LorentzTransform cms_boost;
if (ups.p3().mod() > 0.001)
cms_boost = LorentzTransform::mkFrameTransformFromBeta(ups.momentum().betaVec());
Particles unstable;
// Find the decay products we want
findDecayProducts(ups, unstable);
for (const Particle& p : unstable) {
double modp = cms_boost.transform(p.momentum()).p3().mod();
if (p.pid() == 20443)
_h_spect[0]->fill(modp);
else
_h_spect[1]->fill(modp);
}
}
// exclusive decay modes
static const map<PdgId, unsigned int>& mode1 = {{20443, 1}, {-211, 1}, {321, 1}};
static const map<PdgId, unsigned int>& mode1CC = {{20443, 1}, {211, 1}, {-321, 1}};
static const map<PdgId, unsigned int>& mode2 = {{445, 1}, {-211, 1}, {321, 1}};
static const map<PdgId, unsigned int>& mode2CC = {{445, 1}, {211, 1}, {-321, 1}};
static const map<PdgId, unsigned int>& mode3 = {{20443, 1}, {211, 1}, {310, 1}};
static const map<PdgId, unsigned int>& mode3CC = {{20443, 1}, {-211, 1}, {310, 1}};
static const map<PdgId, unsigned int>& mode4 = {{445, 1}, {211, 1}, {310, 1}};
static const map<PdgId, unsigned int>& mode4CC = {{445, 1}, {-211, 1}, {310, 1}};
static const map<PdgId, unsigned int>& mode5 = {{20443, 1}, {111, 1}, {321, 1}};
static const map<PdgId, unsigned int>& mode5CC = {{20443, 1}, {111, 1}, {-321, 1}};
static const map<PdgId, unsigned int>& mode6 = {{20443, 1}, {211, 1}, {-211, 1}, {321, 1}};
static const map<PdgId, unsigned int>& mode6CC = {{20443, 1}, {211, 1}, {-211, 1}, {-321, 1}};
static const map<PdgId, unsigned int>& mode7 = {{445, 1}, {211, 1}, {-211, 1}, {321, 1}};
static const map<PdgId, unsigned int>& mode7CC = {{445, 1}, {211, 1}, {-211, 1}, {-321, 1}};
DecayedParticles BB = apply<DecayedParticles>(event, "BB");
// loop over particles
for (unsigned int ix = 0; ix < BB.decaying().size(); ++ix) {
int sign = 1, imode = -1, ichi = 0, iK = 310, ipi = 211;
if (BB.decaying()[ix].abspid() == 511) {
iK = 321;
ipi = -211;
if (BB.decaying()[ix].pid() > 0 && BB.modeMatches(ix, 3, mode1)) {
ichi = 20443;
sign = 1;
imode = 0;
}
else if (BB.decaying()[ix].pid() < 0 && BB.modeMatches(ix, 3, mode1CC)) {
ichi = 20443;
sign = -1;
imode = 0;
}
else if (BB.decaying()[ix].pid() > 0 && BB.modeMatches(ix, 3, mode2)) {
ichi = 445;
sign = 1;
imode = 1;
}
else if (BB.decaying()[ix].pid() < 0 && BB.modeMatches(ix, 3, mode2CC)) {
ichi = 445;
sign = -1;
imode = 1;
}
else
continue;
}
else {
if (BB.decaying()[ix].pid() > 0 && BB.modeMatches(ix, 3, mode3)) {
ichi = 20443;
sign = 1;
imode = 2;
}
else if (BB.decaying()[ix].pid() < 0 && BB.modeMatches(ix, 3, mode3CC)) {
ichi = 20443;
sign = -1;
imode = 2;
}
else if (BB.decaying()[ix].pid() > 0 && BB.modeMatches(ix, 3, mode4)) {
ichi = 445;
sign = 1;
imode = 3;
}
else if (BB.decaying()[ix].pid() < 0 && BB.modeMatches(ix, 3, mode4CC)) {
ichi = 445;
sign = -1;
imode = 3;
}
else if (BB.decaying()[ix].pid() > 0 && BB.modeMatches(ix, 3, mode5)) {
ichi = 20443;
sign = 1;
imode = 4;
iK = 321;
ipi = 111;
}
else if (BB.decaying()[ix].pid() < 0 && BB.modeMatches(ix, 3, mode5CC)) {
ichi = 20443;
sign = -1;
imode = 4;
iK = 321;
ipi = 111;
}
else if (BB.decaying()[ix].pid() > 0 && BB.modeMatches(ix, 4, mode6)) {
ichi = 20443;
sign = 1;
imode = 5;
iK = 321;
}
else if (BB.decaying()[ix].pid() < 0 && BB.modeMatches(ix, 4, mode6CC)) {
ichi = 20443;
sign = -1;
imode = 5;
iK = 321;
}
else if (BB.decaying()[ix].pid() > 0 && BB.modeMatches(ix, 4, mode7)) {
ichi = 445;
sign = 1;
imode = 6;
iK = 321;
}
else if (BB.decaying()[ix].pid() < 0 && BB.modeMatches(ix, 4, mode7CC)) {
ichi = 445;
sign = -1;
imode = 6;
iK = 321;
}
else
continue;
}
if (ipi != 111) ipi *= sign;
if (iK != 310) iK *= sign;
const Particle& pip = BB.decayProducts()[ix].at(ipi)[0];
const Particle& K = BB.decayProducts()[ix].at(iK)[0];
const Particle& chi = BB.decayProducts()[ix].at(ichi)[0];
if (imode < 5) {
_h_three[imode][0]->fill((pip.momentum() + K.momentum()).mass());
_h_three[imode][1]->fill((chi.momentum() + pip.momentum()).mass());
}
else {
const Particle& pim = BB.decayProducts()[ix].at(-ipi)[0];
FourMomentum ppi = pim.momentum() + pip.momentum();
imode -= 5;
_h_four[imode][0]->fill((chi.momentum() + ppi).mass());
_h_four[imode][1]->fill((chi.momentum() + pim.momentum()).mass());
_h_four[imode][1]->fill((chi.momentum() + pip.momentum()).mass());
_h_four[imode][2]->fill((K.momentum() + ppi).mass());
_h_four[imode][3]->fill((K.momentum() + pim.momentum()).mass());
_h_four[imode][4]->fill(ppi.mass());
}
}
}
/// Normalise histograms etc., after the run
void finalize() {
for (unsigned int ix = 0; ix < 2; ++ix) {
scale(_h_spect[ix], 1e4 / 2. / *_wUps);
for (unsigned int iy = 0; iy < 5; ++iy) {
normalize(_h_three[iy][ix], 1., false);
normalize(_h_four[ix][iy], 1., false);
}
}
}
/// @}
/// @name Histograms
/// @{
Histo1DPtr _h_spect[2];
Histo1DPtr _h_three[5][2];
Histo1DPtr _h_four[2][5];
CounterPtr _wUps;
/// @}
// BEGIN YODA_SCATTER2D_V2 /REF/BELLE_2016_I1408873/d03-x01-y01
// BEGIN YODA_SCATTER2D_V2 /REF/BELLE_2016_I1408873/d03-x02-y01
// BEGIN YODA_SCATTER2D_V2 /REF/BELLE_2016_I1408873/d03-x01-y02
// BEGIN YODA_SCATTER2D_V2 /REF/BELLE_2016_I1408873/d03-x02-y02
// BEGIN YODA_SCATTER2D_V2 /REF/BELLE_2016_I1408873/d04-x01-y01
// BEGIN YODA_SCATTER2D_V2 /REF/BELLE_2016_I1408873/d04-x02-y01
// BEGIN YODA_SCATTER2D_V2 /REF/BELLE_2016_I1408873/d04-x03-y01
// BEGIN YODA_SCATTER2D_V2 /REF/BELLE_2016_I1408873/d04-x01-y02
// BEGIN YODA_SCATTER2D_V2 /REF/BELLE_2016_I1408873/d04-x02-y02
// BEGIN YODA_SCATTER2D_V2 /REF/BELLE_2016_I1408873/d04-x03-y02
};
RIVET_DECLARE_PLUGIN(BELLE_2016_I1408873);
} ```