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| // -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/Beam.hh"
#include "Rivet/Projections/UnstableParticles.hh"
#include "Rivet/Projections/Thrust.hh"
#include "Rivet/Tools/BinnedHistogram.hh"
#include "Rivet/Projections/ChargedFinalState.hh"
#include <sstream>
namespace Rivet {
/// @brief Lambda polarization at LEP1
class ALEPH_1996_I415745 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(ALEPH_1996_I415745);
/// @name Analysis methods
//@{
/// Book histograms and initialise projections before the run
void init() {
// Initialise and register projections
declare(Beam(), "Beams");
const ChargedFinalState cfs;
const Thrust thrust(cfs);
declare(thrust, "Thrust");
declare(UnstableParticles(), "UFS");
// Book histograms
{Histo1DPtr temp; _h_ctheta.add(0.1 ,0.15,book(temp, "/TMP/ctheta_0",20,-1.,1.));}
{Histo1DPtr temp; _h_ctheta.add(0.15,0.2 ,book(temp, "/TMP/ctheta_1",20,-1.,1.));}
{Histo1DPtr temp; _h_ctheta.add(0.2 ,0.3 ,book(temp, "/TMP/ctheta_2",20,-1.,1.));}
{Histo1DPtr temp; _h_ctheta.add(0.3 ,0.4 ,book(temp, "/TMP/ctheta_3",20,-1.,1.));}
{Histo1DPtr temp; _h_ctheta.add(0.4 ,1. ,book(temp, "/TMP/ctheta_4",20,-1.,1.));}
book(_h_ctheta_large,"/TMP/ctheta_large",20,-1.,1.);
{Histo1DPtr temp; _h_plus_cphi .add(0.3,0.6,book(temp, "/TMP/cphiP_0",10,0.,1.));}
{Histo1DPtr temp; _h_plus_cphi .add(0.6,0.9,book(temp, "/TMP/cphiP_1",10,0.,1.));}
{Histo1DPtr temp; _h_plus_cphi .add(0.9,1.2,book(temp, "/TMP/cphiP_2",10,0.,1.));}
{Histo1DPtr temp; _h_plus_cphi .add(1.2,1.5,book(temp, "/TMP/cphiP_3",10,0.,1.));}
{Histo1DPtr temp; _h_minus_cphi.add(0.3,0.6,book(temp, "/TMP/cphiM_0",10,0.,1.));}
{Histo1DPtr temp; _h_minus_cphi.add(0.6,0.9,book(temp, "/TMP/cphiM_1",10,0.,1.));}
{Histo1DPtr temp; _h_minus_cphi.add(0.9,1.2,book(temp, "/TMP/cphiM_2",10,0.,1.));}
{Histo1DPtr temp; _h_minus_cphi.add(1.2,1.5,book(temp, "/TMP/cphiM_3",10,0.,1.));}
book(_h_plus_cphi_low , "/TMP/cphiP_low" ,10,0.,1.);
book(_h_plus_cphi_mid , "/TMP/cphiP_mid" ,10,0.,1.);
book(_h_plus_cphi_high , "/TMP/cphiP_high",10,0.,1.);
book(_h_minus_cphi_low , "/TMP/cphiM_low" ,10,0.,1.);
book(_h_minus_cphi_mid , "/TMP/cphiM_mid" ,10,0.,1.);
book(_h_minus_cphi_high, "/TMP/cphiM_high",10,0.,1.);
{Histo1DPtr temp; _h_plus_lam.add(0.1 ,0.15,book(temp, "/TMP/lamP_0",20,-1.,1.));}
{Histo1DPtr temp; _h_plus_lam.add(0.15,0.2 ,book(temp, "/TMP/lamP_1",20,-1.,1.));}
{Histo1DPtr temp; _h_plus_lam.add(0.2 ,0.3 ,book(temp, "/TMP/lamP_2",20,-1.,1.));}
{Histo1DPtr temp; _h_plus_lam.add(0.3 ,0.4 ,book(temp, "/TMP/lamP_3",20,-1.,1.));}
{Histo1DPtr temp; _h_plus_lam.add(0.4 ,1. ,book(temp, "/TMP/lamP_4",20,-1.,1.));}
{Histo1DPtr temp; _h_minus_lam.add(0.1 ,0.15,book(temp, "/TMP/lamM_0",20,-1.,1.));}
{Histo1DPtr temp; _h_minus_lam.add(0.15,0.2 ,book(temp, "/TMP/lamM_1",20,-1.,1.));}
{Histo1DPtr temp; _h_minus_lam.add(0.2 ,0.3 ,book(temp, "/TMP/lamM_2",20,-1.,1.));}
{Histo1DPtr temp; _h_minus_lam.add(0.3 ,0.4 ,book(temp, "/TMP/lamM_3",20,-1.,1.));}
{Histo1DPtr temp; _h_minus_lam.add(0.4 ,1. ,book(temp, "/TMP/lamM_4",20,-1.,1.));}
}
/// Perform the per-event analysis
void analyze(const Event& event) {
// Get beams and average beam momentum
const ParticlePair& beams = apply<Beam>(event, "Beams").beams();
const double meanBeamMom = ( beams.first.p3().mod() +
beams.second.p3().mod() ) / 2.0;
Vector3 beamAxis;
if(beams.first.pid()==-11) {
beamAxis = beams.first .momentum().p3().unit();
}
else {
beamAxis = beams.second.momentum().p3().unit();
}
MSG_DEBUG("Avg beam momentum = " << meanBeamMom);
// thrust, to define an axis
const Thrust& thrust = apply<Thrust>(event, "Thrust");
const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
for(const Particle & lambda : ufs.particles(Cuts::abspid==3122)) {
double z = lambda.momentum().p3().mod()/meanBeamMom;
int sign = lambda.pid()/3122;
Vector3 axis1 = lambda.momentum().p3().unit();
// assymetry
double cLam = axis1.dot(beamAxis);
if(sign>0)
_h_plus_lam .fill(z,cLam);
else
_h_minus_lam.fill(z,cLam);
if(lambda.children().size()!=2) continue;
// look at the decay products
Particle proton,pion;
if(lambda.children()[0].pid()==sign*2212 &&
lambda.children()[1].pid()==-sign*211) {
proton = lambda.children()[0];
pion = lambda.children()[1];
}
else if(lambda.children()[1].pid()==sign*2212 &&
lambda.children()[0].pid()==-sign*211) {
proton = lambda.children()[1];
pion = lambda.children()[0];
}
else
continue;
// boost to the lambda rest frame
LorentzTransform boost = LorentzTransform::mkFrameTransformFromBeta(lambda.momentum().betaVec());
FourMomentum pproton = boost.transform(proton.momentum());
// longitudinal polarization
double ctheta = axis1.dot(pproton.p3().unit());
_h_ctheta.fill(z,ctheta);
if(z>=0.3) _h_ctheta_large->fill(ctheta);
// transverse polarization
if(z>0.15) {
Vector3 axis2;
if(lambda.momentum().p3().dot(thrust.thrustAxis())>=0.) {
axis2 = thrust.thrustAxis();
}
else {
axis2 =-thrust.thrustAxis();
}
Vector3 axis3 = axis2.cross(axis1).unit();
double pT = sqrt(sqr(thrust.thrustMajorAxis().dot(lambda.momentum().p3()))+
sqr(thrust.thrustMinorAxis().dot(lambda.momentum().p3())));
double cPhi = axis3.dot(pproton.p3().unit());
if(cPhi>0.) {
_h_plus_cphi .fill(pT,cPhi);
if(pT>0.3)
_h_plus_cphi_low ->fill(cPhi);
if(pT>0.6)
_h_plus_cphi_mid ->fill(cPhi);
if(pT>1.5)
_h_plus_cphi_high->fill(cPhi);
}
else {
_h_minus_cphi.fill(pT,abs(cPhi));
if(pT>0.3)
_h_minus_cphi_low ->fill(abs(cPhi));
if(pT>0.6)
_h_minus_cphi_mid ->fill(abs(cPhi));
if(pT>1.5)
_h_minus_cphi_high->fill(abs(cPhi));
}
}
}
}
pair<double,double> calcAlpha(Histo1DPtr hist) {
if(hist->numEntries()==0.) return make_pair(0.,0.);
double sum1(0.),sum2(0.);
for (auto bin : hist->bins() ) {
double Oi = bin.area();
if(Oi==0.) continue;
double ai = 0.5*(bin.xMax()-bin.xMin());
double bi = 0.5*ai*(bin.xMax()+bin.xMin());
double Ei = bin.areaErr();
sum1 += sqr(bi/Ei);
sum2 += bi/sqr(Ei)*(Oi-ai);
}
return make_pair(sum2/sum1,sqrt(1./sum1));
}
pair<double,double> calcAsymmetry(Scatter2DPtr hist,unsigned int mode) {
double sum1(0.),sum2(0.);
for (auto bin : hist->points() ) {
double Oi = bin.y();
if(Oi==0.) continue;
double bi;
if(mode==0)
bi = 0.25*(bin.xMax()-bin.xMin())*(bin.xMax()+bin.xMin());
else
bi = 4.*(bin.xMax()+bin.xMin())/(3.+sqr(bin.xMax())+bin.xMax()*bin.xMin()+sqr(bin.xMin()));
double Ei = bin.yErrAvg();
sum1 += sqr(bi/Ei);
sum2 += bi/sqr(Ei)*Oi;
}
return make_pair(sum2/sum1,sqrt(1./sum1));
}
/// Normalise histograms etc., after the run
void finalize() {
// longitudinal polarization
vector<double> x_val = {0.125 , 0.175,0.25,0.35,0.70};
vector<double> x_err = {0.025 , 0.025,0.05,0.05,0.30};
unsigned int ipoint=0;
double aLam = 0.642;
Scatter2DPtr h_long;
book(h_long,1,1,1);
for(Histo1DPtr & hist : _h_ctheta.histos()) {
normalize(hist);
pair<double,double> alpha = calcAlpha(hist);
alpha.first /=aLam;
alpha.second /=aLam;
h_long->addPoint(x_val[ipoint], alpha.first, make_pair(x_err[ipoint],x_err[ipoint]),
make_pair(alpha.second,alpha.second) );
++ipoint;
}
normalize(_h_ctheta_large);
pair<double,double> alpha = calcAlpha(_h_ctheta_large);
alpha.first /=aLam;
alpha.second /=aLam;
Scatter2DPtr h_long_l;
book(h_long_l,1,2,1);
h_long_l->addPoint(0.65, alpha.first, make_pair(0.35,0.35), make_pair(alpha.second,alpha.second) );
// transverse polarization
vector<double> pT_val = {0.45,0.75,1.05,1.35};
vector<double> pT_err = {0.15,0.15,0.15,0.15};
Scatter2DPtr h_trans;
book(h_trans,2,1,1);
for(unsigned int ix=0;ix<4;++ix) {
normalize(_h_plus_cphi.histos()[ix] );
normalize(_h_minus_cphi.histos()[ix]);
std::ostringstream title;
title << "/TMP/a_cphi_" << ix;
Scatter2DPtr sTemp;
book(sTemp,title.str());
asymm(_h_plus_cphi.histos()[ix],_h_minus_cphi.histos()[ix],sTemp);
pair<double,double> alpha = calcAsymmetry(sTemp,0);
alpha.first /=aLam;
alpha.second /=aLam;
h_trans->addPoint(pT_val[ix], alpha.first, make_pair(pT_err[ix],pT_err[ix]),
make_pair(alpha.second,alpha.second) );
}
Scatter2DPtr sLow;
book(sLow,"/TMP/a_cphi_low");
asymm(_h_plus_cphi_low,_h_minus_cphi_low,sLow);
alpha = calcAsymmetry(sLow,0);
alpha.first /=aLam;
alpha.second /=aLam;
Scatter2DPtr h_trans_low;
book(h_trans_low,2,3,1);
h_trans_low->addPoint(5.15, alpha.first, make_pair(4.85,4.85), make_pair(alpha.second,alpha.second) );
Scatter2DPtr sMid;
book(sMid,"/TMP/a_cphi_mid");
asymm(_h_plus_cphi_mid,_h_minus_cphi_mid,sMid);
alpha = calcAsymmetry(sMid,0);
alpha.first /=aLam;
alpha.second /=aLam;
Scatter2DPtr h_trans_mid;
book(h_trans_mid,2,4,1);
h_trans_mid->addPoint(5.3, alpha.first, make_pair(4.7,4.7), make_pair(alpha.second,alpha.second) );
Scatter2DPtr sHigh;
book(sHigh,"/TMP/a_cphi_high");
asymm(_h_plus_cphi_high,_h_minus_cphi_high,sHigh);
alpha = calcAsymmetry(sHigh,0);
alpha.first /=aLam;
alpha.second /=aLam;
Scatter2DPtr h_trans_high;
book(h_trans_high,2,2,1);
h_trans_high->addPoint(5.75, alpha.first, make_pair(4.25,4.25), make_pair(alpha.second,alpha.second) );
// asyymetry
vector<double> x_val2 = {1.220000e-01,1.730000e-01,2.410000e-01,3.420000e-01,4.950000e-01};
vector<double> x_err2 = {2.200000e-02,2.300000e-02,4.100000e-02,4.200000e-02,9.500000e-02};
vector<double> x_err3 = {2.800000e-02,2.700000e-02,5.900000e-02,5.800000e-02,5.050000e-01};
Scatter2DPtr h_asym;
book(h_asym,3,1,1);
for(unsigned int ix=0;ix<5;++ix) {
normalize(_h_plus_lam.histos()[ix] );
normalize(_h_minus_lam.histos()[ix]);
std::ostringstream title;
title << "/TMP/a_lam_" << ix;
Scatter2DPtr sTemp;
book(sTemp,title.str());
asymm(_h_plus_lam.histos()[ix],_h_minus_lam.histos()[ix],sTemp);
pair<double,double> alpha = calcAsymmetry(sTemp,1);
h_asym->addPoint(x_val2[ix], alpha.first, make_pair(x_err2[ix],x_err3[ix]),
make_pair(alpha.second,alpha.second) );
}
}
//@}
/// @name Histograms
//@{
BinnedHistogram _h_ctheta,_h_plus_cphi,_h_minus_cphi,_h_plus_lam,_h_minus_lam;
Histo1DPtr _h_ctheta_large;
Histo1DPtr _h_minus_cphi_low,_h_minus_cphi_mid,_h_minus_cphi_high;
Histo1DPtr _h_plus_cphi_low ,_h_plus_cphi_mid ,_h_plus_cphi_high ;
//@}
};
// The hook for the plugin system
RIVET_DECLARE_PLUGIN(ALEPH_1996_I415745);
}
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