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Rivet analyses reference
BELLE_2016_I1408873
$\chi_{c1}$ and $\chi_{c2}$ production in $B$ decays
Experiment: BELLE (KEKB)
Inspire ID: 1408873
Status: VALIDATED NOHEPDATA
Authors:
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
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245 | // -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/UnstableParticles.hh"
#include "Rivet/Projections/DecayedParticles.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);
}
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