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| // -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/ChargedFinalState.hh"
#include "Rivet/Projections/ChargedLeptons.hh"
namespace Rivet {
/// @brief CDF Run II underlying event in Drell-Yan
///
/// @author Hendrik Hoeth
///
/// Measurement of the underlying event in Drell-Yan
/// \f$ Z/\gamma^* \to e^+ e^- \f$ and
/// \f$ Z/\gamma^* \to \mu^+ \mu^- \f$ events. The reconstructed
/// Z defines the \f$ \phi \f$ orientation. A Z mass window cut is applied.
///
/// @par Run conditions
///
/// @arg \f$ \sqrt{s} = \f$ 1960 GeV
/// @arg produce Drell-Yan events
/// @arg Set particles with c*tau > 10 mm stable
/// @arg Z decay mode: Z -> e+e- and Z -> mu+mu-
/// @arg gamma decay mode: gamma -> e+e- and gamma -> mu+mu-
/// @arg minimum invariant mass of the fermion pair coming from the Z/gamma: 70 GeV
class CDF_2010_S8591881_DY : public Analysis {
public:
RIVET_DEFAULT_ANALYSIS_CTOR(CDF_2010_S8591881_DY);
/// @name Analysis methods
//@{
void init() {
// Set up projections
const ChargedFinalState cfs(Cuts::abseta < 1.0 && Cuts::pT >= 0.5*GeV);
const ChargedFinalState clfs(Cuts::abseta < 1.0 && Cuts::pT >= 20*GeV);
declare(cfs, "FS");
declare(ChargedLeptons(clfs), "CL");
// Book histograms
book(_hist_tnchg , 1, 1, 1);
book(_hist_pnchg , 1, 1, 2);
book(_hist_anchg , 1, 1, 3);
book(_hist_pmaxnchg , 2, 1, 1);
book(_hist_pminnchg , 2, 1, 2);
book(_hist_pdifnchg , 2, 1, 3);
book(_hist_tcptsum , 3, 1, 1);
book(_hist_pcptsum , 3, 1, 2);
book(_hist_acptsum , 3, 1, 3);
book(_hist_pmaxcptsum , 4, 1, 1);
book(_hist_pmincptsum , 4, 1, 2);
book(_hist_pdifcptsum , 4, 1, 3);
book(_hist_tcptave , 5, 1, 1);
book(_hist_pcptave , 5, 1, 2);
book(_hist_tcptmax , 6, 1, 1);
book(_hist_pcptmax , 6, 1, 2);
book(_hist_zptvsnchg , 7, 1, 1);
book(_hist_cptavevsnchg , 8, 1, 1);
book(_hist_cptavevsnchgsmallzpt , 9, 1, 1);
}
/// Do the analysis
void analyze(const Event& e) {
const FinalState& fs = apply<FinalState>(e, "FS");
const size_t numParticles = fs.particles().size();
// Even if we only generate hadronic events, we still need a cut on numCharged >= 2.
if (numParticles < 1) {
MSG_DEBUG("Failed multiplicity cut");
vetoEvent;
}
// Get the leptons
const Particles& leptons = apply<ChargedLeptons>(e, "CL").chargedLeptons();
// We want exactly two leptons of the same flavour.
MSG_DEBUG("lepton multiplicity = " << leptons.size());
if (leptons.size() != 2 || leptons[0].pid() != -leptons[1].pid() ) vetoEvent;
// Lepton pT > 20 GeV
if (leptons[0].pT()/GeV <= 20 || leptons[1].pT()/GeV <= 20) vetoEvent;
// Lepton pair should have an invariant mass between 70 and 110 and |eta| < 6
const FourMomentum dilepton = leptons[0].momentum() + leptons[1].momentum();
if (!inRange(dilepton.mass()/GeV, 70., 110.) || fabs(dilepton.eta()) >= 6) vetoEvent;
MSG_DEBUG("Dilepton mass = " << dilepton.mass()/GeV << " GeV");
MSG_DEBUG("Dilepton pT = " << dilepton.pT()/GeV << " GeV");
// Calculate the observables
size_t numToward(0), numAway(0);
long int numTrans1(0), numTrans2(0);
double ptSumToward(0.0), ptSumTrans1(0.0), ptSumTrans2(0.0), ptSumAway(0.0);
double ptMaxToward(0.0), ptMaxTrans1(0.0), ptMaxTrans2(0.0), ptMaxAway(0.0);
const double phiZ = dilepton.azimuthalAngle();
const double pTZ = dilepton.pT();
/// @todo Replace with for
for (Particles::const_iterator p = fs.particles().begin(); p != fs.particles().end(); ++p) {
// Don't use the leptons
/// @todo Replace with PID::isLepton
if (abs(p->pid()) < 20) continue;
const double dPhi = deltaPhi(p->momentum().phi(), phiZ);
const double pT = p->pT();
double rotatedphi = p->momentum().phi() - phiZ;
while (rotatedphi < 0) rotatedphi += 2*PI;
if (dPhi < PI/3.0) {
ptSumToward += pT;
++numToward;
if (pT > ptMaxToward)
ptMaxToward = pT;
} else if (dPhi < 2*PI/3.0) {
if (rotatedphi <= PI) {
ptSumTrans1 += pT;
++numTrans1;
if (pT > ptMaxTrans1)
ptMaxTrans1 = pT;
}
else {
ptSumTrans2 += pT;
++numTrans2;
if (pT > ptMaxTrans2)
ptMaxTrans2 = pT;
}
} else {
ptSumAway += pT;
++numAway;
if (pT > ptMaxAway)
ptMaxAway = pT;
}
// We need to subtract the two leptons from the number of particles to get the correct multiplicity
_hist_cptavevsnchg->fill(numParticles-2, pT);
if (pTZ < 10)
_hist_cptavevsnchgsmallzpt->fill(numParticles-2, pT);
}
// Fill the histograms
_hist_tnchg->fill(pTZ, numToward/(4*PI/3));
_hist_pnchg->fill(pTZ, (numTrans1+numTrans2)/(4*PI/3));
_hist_pmaxnchg->fill(pTZ, (numTrans1>numTrans2 ? numTrans1 : numTrans2)/(2*PI/3));
_hist_pminnchg->fill(pTZ, (numTrans1<numTrans2 ? numTrans1 : numTrans2)/(2*PI/3));
_hist_pdifnchg->fill(pTZ, abs(numTrans1-numTrans2)/(2*PI/3));
_hist_anchg->fill(pTZ, numAway/(4*PI/3));
_hist_tcptsum->fill(pTZ, ptSumToward/(4*PI/3));
_hist_pcptsum->fill(pTZ, (ptSumTrans1+ptSumTrans2)/(4*PI/3));
_hist_pmaxcptsum->fill(pTZ, (ptSumTrans1>ptSumTrans2 ? ptSumTrans1 : ptSumTrans2)/(2*PI/3));
_hist_pmincptsum->fill(pTZ, (ptSumTrans1<ptSumTrans2 ? ptSumTrans1 : ptSumTrans2)/(2*PI/3));
_hist_pdifcptsum->fill(pTZ, fabs(ptSumTrans1-ptSumTrans2)/(2*PI/3));
_hist_acptsum->fill(pTZ, ptSumAway/(4*PI/3));
if (numToward > 0) {
_hist_tcptave->fill(pTZ, ptSumToward/numToward);
_hist_tcptmax->fill(pTZ, ptMaxToward);
}
if ((numTrans1+numTrans2) > 0) {
_hist_pcptave->fill(pTZ, (ptSumTrans1+ptSumTrans2)/(numTrans1+numTrans2));
_hist_pcptmax->fill(pTZ, (ptMaxTrans1 > ptMaxTrans2 ? ptMaxTrans1 : ptMaxTrans2));
}
// We need to subtract the two leptons from the number of particles to get the correct multiplicity
_hist_zptvsnchg->fill(numParticles-2, pTZ);
}
// void finalize() { }
//@}
private:
Profile1DPtr _hist_tnchg;
Profile1DPtr _hist_pnchg;
Profile1DPtr _hist_pmaxnchg;
Profile1DPtr _hist_pminnchg;
Profile1DPtr _hist_pdifnchg;
Profile1DPtr _hist_anchg;
Profile1DPtr _hist_tcptsum;
Profile1DPtr _hist_pcptsum;
Profile1DPtr _hist_pmaxcptsum;
Profile1DPtr _hist_pmincptsum;
Profile1DPtr _hist_pdifcptsum;
Profile1DPtr _hist_acptsum;
Profile1DPtr _hist_tcptave;
Profile1DPtr _hist_pcptave;
Profile1DPtr _hist_tcptmax;
Profile1DPtr _hist_pcptmax;
Profile1DPtr _hist_zptvsnchg;
Profile1DPtr _hist_cptavevsnchg;
Profile1DPtr _hist_cptavevsnchgsmallzpt;
};
RIVET_DECLARE_ALIASED_PLUGIN(CDF_2010_S8591881_DY, CDF_2010_I849042_DY);
}
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