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| // -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/UnstableParticles.hh"
#include "Rivet/Projections/Beam.hh"
namespace Rivet {
/// @brief charmonium production at 10.6 GeV
class BELLE_2002_I563840 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(BELLE_2002_I563840);
/// @name Analysis methods
///@{
/// Book histograms and initialise projections before the run
void init() {
// projections
declare(UnstableParticles(),"UFS");
// book the histograms
// spectra
book(_h_Jpsi,3,1,1);
book(_h_feed,3,1,2);
book(_h_Psi2,3,2,1);
// cross sections
book(_h_sig_JPsi_all ,1,1,1);
book(_h_sig_Jpsi_high,1,2,1);
book(_h_sig_Jpsi_feed,1,2,2);
book(_h_sig_Psi2_high,1,2,3);
// angular distributions
vector<double> bins = {2.,2.6,3.4,4.9};
for(unsigned int ix=0;ix<3;++ix) {
Histo1DPtr temp;
// book cos theta*
if(ix<=1) {
std::ostringstream title;
title << "/TMP/cThetaStar_" << ix+1;
book(temp,title.str(),5,-1.,1.);
}
else {
book(temp,4,1,2);
}
_h_cThetaStar.add(bins[ix],bins[ix]+1,temp);
// book cos theta_H
if(ix<=1) {
std::ostringstream title;
title << "/TMP/cThetaH_" << ix+1;
book(temp,title.str(),5,-1.,1.);
}
else {
book(temp,4,2,2);
}
_h_cThetaH.add(bins[ix],bins[ix]+1,temp);
}
book(_h_cS_low,4,1,1);
book(_h_cS_high,"/TMP/cS_high",5,-1.,1.);
book(_h_cH_low,4,2,1);
book(_h_cH_high,"/TMP/cH_high",5,-1.,1.);
}
void findLeptons(const Particle & mother,
unsigned int & nstable,
Particles& lp, Particles& lm) {
for(const Particle & p : mother.children()) {
int id = p.pid();
if ( id == 11 || id == 13 ) {
lm.push_back(p);
++nstable;
}
else if (id == -11 || id==-13) {
lp.push_back(p);
++nstable;
}
else if ( !p.children().empty() ) {
findLeptons(p,nstable,lp,lm);
}
else
++nstable;
}
}
/// Perform the per-event analysis
void analyze(const Event& event) {
for(const Particle & p : apply<UnstableParticles>("UFS",event).particles(Cuts::pid==443 or Cuts::pid==100443 )) {
LorentzTransform boost = cmsTransform( beams() );
// check if prompt (i.e. not from B decay)
if(p.fromBottom()) continue;
bool feedDown = false;
FourMomentum mom = boost.transform(p.momentum());
double pStar = mom.p3().mod();
if(p.pid()==443) {
Particle parent=p;
while(!parent.parents().empty()) {
parent=parent.parents()[0];
if(p.pid()==parent.pid()) continue;
if((parent.abspid()%1000)/10==44) {
feedDown=true;
break;
}
}
_h_Jpsi->fill(pStar);
_h_sig_JPsi_all->fill(10.6);
if(pStar>2.) {
_h_sig_Jpsi_high->fill(10.6);
if(feedDown) {
_h_feed->fill(pStar);
_h_sig_Jpsi_feed->fill(10.6);
}
double cThetaS = cos(mom.p3().polarAngle());
_h_cThetaStar.fill(pStar,cThetaS);
if(pStar<3.4) _h_cS_low ->fill(cThetaS);
else _h_cS_high->fill(cThetaS);
// leptons from J/psi decay
unsigned int nstable = 0;
Particles lp, lm;
findLeptons(p,nstable,lp,lm);
if(nstable==2&&lp.size()==1&&lm.size()==1) {
FourMomentum pl = boost.transform(lp[0].momentum());
LorentzTransform b2 = LorentzTransform::mkFrameTransformFromBeta(p.momentum().betaVec());
pl = b2.transform(pl);
double cThetaH = pl.p3().unit().dot(p.p3().unit());
_h_cThetaH.fill(pStar,cThetaH);
if(pStar<3.4) _h_cH_low ->fill(cThetaH);
else _h_cH_high->fill(cThetaH);
}
}
}
else {
_h_Psi2->fill(pStar);
if(pStar>2.) _h_sig_Psi2_high->fill(10.6);
}
}
}
pair<double,pair<double,double> > calcAlpha(Histo1DPtr hist) {
if(hist->numEntries()==0.) return make_pair(0.,make_pair(0.,0.));
double sum1(0.),sum2(0.),sum3(0.),sum4(0.),sum5(0.);
for (auto bin : hist->bins() ) {
double Oi = bin.area();
if(Oi==0.) continue;
double a = 1.5*(bin.xMax() - bin.xMin());
double b = 0.5*(pow(bin.xMax(),3) - pow(bin.xMin(),3));
double Ei = bin.areaErr();
sum1 += a*Oi/sqr(Ei);
sum2 += b*Oi/sqr(Ei);
sum3 += sqr(a)/sqr(Ei);
sum4 += sqr(b)/sqr(Ei);
sum5 += a*b/sqr(Ei);
}
// calculate alpha
double alpha = (-3*sum1 + 9*sum2 + sum3 - 3*sum5)/(sum1 - 3*sum2 + 3*sum4 - sum5);
// and error
double cc = -pow((sum3 + 9*sum4 - 6*sum5),3);
double bb = -2*sqr(sum3 + 9*sum4 - 6*sum5)*(sum1 - 3*sum2 + 3*sum4 - sum5);
double aa = sqr(sum1 - 3*sum2 + 3*sum4 - sum5)*(-sum3 - 9*sum4 + sqr(sum1 - 3*sum2 + 3*sum4 - sum5) + 6*sum5);
double dis = sqr(bb)-4.*aa*cc;
if(dis>0.) {
dis = sqrt(dis);
return make_pair(alpha,make_pair(0.5*(-bb+dis)/aa,-0.5*(-bb-dis)/aa));
}
else {
return make_pair(alpha,make_pair(0.,0.));
}
}
/// Normalise histograms etc., after the run
void finalize() {
// spectra
normalize(_h_Jpsi,1.,false);
normalize(_h_feed,1.,false);
normalize(_h_Psi2,1.,false);
// cross sections
double fact = 1./sumOfWeights()*crossSection()/picobarn;
scale(_h_sig_JPsi_all ,fact);
scale(_h_sig_Jpsi_high,fact);
scale(_h_sig_Jpsi_feed,fact);
scale(_h_sig_Psi2_high,fact);
// angular dists and parameters from them
vector<double> bins = {2.,2.6,3.4,4.9};
Scatter2DPtr _h_A;
book(_h_A ,2,1,1);
Scatter2DPtr _h_alpha;
book(_h_alpha,2,1,2);
for(unsigned int ix=0;ix<3;++ix) {
normalize(_h_cThetaStar.histos()[ix]);
pair<double,pair<double,double> > alpha = calcAlpha(_h_cThetaStar.histos()[ix]);
double centre = 0.5*(bins[ix+1]+bins[ix]);
double width = 0.5*(bins[ix+1]-bins[ix]);
_h_A->addPoint(centre, alpha.first, make_pair(width,width),
make_pair(alpha.second.first,alpha.second.second) );
normalize(_h_cThetaH.histos()[ix]);
alpha = calcAlpha(_h_cThetaH.histos()[ix]);
_h_alpha->addPoint(centre, alpha.first, make_pair(width,width),
make_pair(alpha.second.first,alpha.second.second) );
}
double centre1 = 0.5*(bins[2]+bins[0]);
double width1 = 0.5*(bins[2]-bins[0]);
double centre2 = 0.5*(bins[3]+bins[0]);
double width2 = 0.5*(bins[3]-bins[0]);
normalize(_h_cS_low);
pair<double,pair<double,double> > alpha = calcAlpha(_h_cS_low);
book(_h_A ,2,2,1);
_h_A->addPoint(centre1, alpha.first, make_pair(width1,width1),
make_pair(alpha.second.first,alpha.second.second) );
normalize(_h_cS_high);
alpha = calcAlpha(_h_cS_high);
book(_h_A ,2,3,1);
_h_A->addPoint(centre2, alpha.first, make_pair(width2,width2),
make_pair(alpha.second.first,alpha.second.second) );
normalize(_h_cH_low);
alpha = calcAlpha(_h_cH_low);
book(_h_alpha,2,2,2);
_h_alpha->addPoint(centre1, alpha.first, make_pair(width1,width1),
make_pair(alpha.second.first,alpha.second.second) );
normalize(_h_cH_high);
alpha = calcAlpha(_h_cH_high);
book(_h_alpha,2,3,2);
_h_alpha->addPoint(centre2, alpha.first, make_pair(width2,width2),
make_pair(alpha.second.first,alpha.second.second) );
}
///@}
/// @name Histograms
///@{
Histo1DPtr _h_Jpsi,_h_Psi2,_h_feed;
Histo1DPtr _h_sig_JPsi_all,_h_sig_Jpsi_high,_h_sig_Jpsi_feed,_h_sig_Psi2_high;
Histo1DPtr _h_cS_low,_h_cS_high,_h_cH_low,_h_cH_high;
BinnedHistogram _h_cThetaStar,_h_cThetaH;
///@}
};
RIVET_DECLARE_PLUGIN(BELLE_2002_I563840);
}
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