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| // -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Math/Constants.hh"
#include "Rivet/Projections/FinalState.hh"
#include "Rivet/Projections/DISKinematics.hh"
namespace Rivet {
/// @brief H1 energy flow and charged particle spectra
///
/// @author Peter Richardson
/// Based on the equivalent HZTool analysis
class H1_1994_S2919893 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(H1_1994_S2919893);
/// @name Analysis methods
//@{
/// Initialise projections and histograms
void init() {
// Projections
declare(DISLepton(), "Lepton");
declare(DISKinematics(), "Kinematics");
declare(FinalState(), "FS");
// Histos
book(_histEnergyFlowLowX ,1, 1, 1);
book(_histEnergyFlowHighX ,1, 1, 2);
book(_histEECLowX ,2, 1, 1);
book(_histEECHighX ,2, 1, 2);
book(_histSpectraW77 ,3, 1, 1);
book(_histSpectraW122 ,3, 1, 2);
book(_histSpectraW169 ,3, 1, 3);
book(_histSpectraW117 ,3, 1, 4);
book(_histPT2 ,4, 1, 1);
book(_w77 .first, "TMP/w77_1");
book(_w122.first, "TMP/w122_1");
book(_w169.first, "TMP/w169_1");
book(_w117.first, "TMP/w117_1");
book(_wEnergy.first, "TMP/wEnergy_1");
book(_w77 .second, "TMP/w77_2");
book(_w122.second, "TMP/w122_2");
book(_w169.second, "TMP/w169_2");
book(_w117.second, "TMP/w117_2");
book(_wEnergy.second, "TMP/wEnergy_2");
}
/// Analyse each event
void analyze(const Event& event) {
// Get the DIS kinematics
const DISKinematics& dk = apply<DISKinematics>(event, "Kinematics");
if ( dk.failed() ) vetoEvent;
const double x = dk.x();
const double w2 = dk.W2();
const double w = sqrt(w2);
// Momentum of the scattered lepton
const DISLepton& dl = apply<DISLepton>(event,"Lepton");
if ( dl.failed() ) return;
const FourMomentum leptonMom = dl.out();
const double ptel = leptonMom.pT();
const double enel = leptonMom.E();
const double thel = leptonMom.angle(dk.beamHadron().mom())/degree;
// Extract the particles other than the lepton
const FinalState& fs = apply<FinalState>(event, "FS");
Particles particles;
particles.reserve(fs.particles().size());
ConstGenParticlePtr dislepGP = dl.out().genParticle();
for(const Particle& p: fs.particles()) {
ConstGenParticlePtr loopGP = p.genParticle();
if (loopGP == dislepGP) continue;
particles.push_back(p);
}
// Cut on the forward energy
double efwd = 0.0;
for (const Particle& p : particles) {
const double th = p.angle(dk.beamHadron())/degree;
if (inRange(th, 4.4, 15)) efwd += p.E();
}
// Apply the cuts
// Lepton energy and angle, w2 and forward energy
MSG_DEBUG("enel/GeV = " << enel/GeV << ", thel = " << thel
<< ", w2 = " << w2 << ", efwd/GeV = " << efwd/GeV);
bool cut = enel/GeV > 14. && thel > 157. && thel < 172.5 && w2 >= 3000. && efwd/GeV > 0.5;
if (!cut) vetoEvent;
// Weight of the event
(x < 1e-3 ? _wEnergy.first : _wEnergy.second)->fill();
// Boost to hadronic CM
const LorentzTransform hcmboost = dk.boostHCM();
// Loop over the particles
long ncharged(0);
for (size_t ip1 = 0; ip1 < particles.size(); ++ip1) {
const Particle& p = particles[ip1];
const double th = p.angle(dk.beamHadron().momentum()) / degree;
// Boost momentum to lab
const FourMomentum hcmMom = hcmboost.transform(p.momentum());
// Angular cut
if (th <= 4.4) continue;
// Energy flow histogram
const double et = fabs(hcmMom.Et());
const double eta = hcmMom.eta();
(x < 1e-3 ? _histEnergyFlowLowX : _histEnergyFlowHighX)->fill(eta, et);
if (PID::charge3(p.pid()) != 0) {
/// @todo Use units in w comparisons... what are the units?
if (w > 50. && w <= 200.) {
double xf= 2 * hcmMom.z() / w;
double pt2 = hcmMom.pT2();
if (w > 50. && w <= 100.) {
_histSpectraW77 ->fill(xf);
} else if (w > 100. && w <= 150.) {
_histSpectraW122->fill(xf);
} else if (w > 150. && w <= 200.) {
_histSpectraW169->fill(xf);
}
_histSpectraW117->fill(xf);
/// @todo Is this profile meant to be filled with 2 weight factors?
_histPT2->fill(xf, pt2/GeV2);
++ncharged;
}
}
// Energy-energy correlation
if (th <= 8.) continue;
double phi1 = p.phi(ZERO_2PI);
double eta1 = p.eta();
double et1 = fabs(p.momentum().Et());
for (size_t ip2 = ip1+1; ip2 < particles.size(); ++ip2) {
const Particle& p2 = particles[ip2];
//double th2 = beamAngle(p2.momentum(), order);
double th2 = p2.angle(dk.beamHadron().momentum()) / degree;
if (th2 <= 8.) continue;
double phi2 = p2.phi(ZERO_2PI);
/// @todo Use angle function
double deltaphi = phi1 - phi2;
if (fabs(deltaphi) > PI) deltaphi = fabs(fabs(deltaphi) - TWOPI);
double eta2 = p2.eta();
double omega = sqrt(sqr(eta1-eta2) + sqr(deltaphi));
double et2 = fabs(p2.momentum().Et());
double wt = et1*et2 / sqr(ptel);
(x < 1e-3 ? _histEECLowX : _histEECHighX)->fill(omega, wt);
}
}
// Factors for normalization
if (w > 50. && w <= 200.) {
if (w <= 100.) {
_w77.first ->fill(ncharged);
_w77.second->fill();
} else if (w <= 150.) {
_w122.first ->fill(ncharged);
_w122.second->fill();
} else {
_w169.first ->fill(ncharged);
_w169.second->fill();
}
_w117.first ->fill(ncharged);
_w117.second->fill();
}
}
// Normalize inclusive single particle distributions to the average number of charged particles per event.
void finalize() {
normalize(_histSpectraW77, *_w77.first/ *_w77.second);
normalize(_histSpectraW122, *_w122.first/ *_w122.second);
normalize(_histSpectraW169, *_w169.first/ *_w169.second);
normalize(_histSpectraW117, *_w117.first/ *_w117.second);
scale(_histEnergyFlowLowX , 1./ *_wEnergy.first );
scale(_histEnergyFlowHighX, 1./ *_wEnergy.second);
scale(_histEECLowX , 1./ *_wEnergy.first );
scale(_histEECHighX, 1./ *_wEnergy.second);
}
//@}
private:
/// Polar angle with right direction of the beam
inline double beamAngle(const FourVector& v, bool order) {
double thel = v.polarAngle()/degree;
if (thel < 0) thel += 180.;
if (!order) thel = 180 - thel;
return thel;
}
/// @name Histograms
/// @{
Histo1DPtr _histEnergyFlowLowX, _histEnergyFlowHighX;
Histo1DPtr _histEECLowX, _histEECHighX;
Histo1DPtr _histSpectraW77, _histSpectraW122, _histSpectraW169, _histSpectraW117;
Profile1DPtr _histPT2;
/// @}
/// @name Storage of weights to calculate averages for normalisation
/// @{
pair<CounterPtr,CounterPtr> _w77, _w122, _w169, _w117, _wEnergy;
/// @}
};
RIVET_DECLARE_ALIASED_PLUGIN(H1_1994_S2919893, H1_1994_I372350);
}
|