How to access constituents' ID in FastJet

[Anterpreet]

TL;DR Summary

How to access constituents' ID in FastJet

Hi,
I am generating p-p collision events using Pythia 8 (8176 version). FastJet is used to cluster these generated particles into jets. I am studying the properties of the constituents of the jet. I can access the properties like pt, phi, rapidity but could not do for PDGID.

I followed http://fastjet.fr/repo/doxygen-3.0.5/09-user__info_8cc_source.html to add additional information of the particle. I successfully accessed the pdgid before clustering into jets but could not access ID of a particle as a jet constituent. Could you please provide any help regarding this ?
(Code used is attached.)

Many thanks in advance,
Anterpreet

 

[LightHero]

#include <iostream>#include "Pythia8/Pythia.h"#include "fastjet/ClusterSequence.hh"#include "fastjet/Selector.hh"using namespace std;using namespace Pythia8;using namespace fastjet; int main() { // Generator. Process selection. LHC initialization. Histogram. Pythia pythia; pythia.readString("Beams:eCM = 13000."); pythia.readString("HardQCD:all = on"); pythia.init(); // Create an output file ofstream outfile; outfile.open("outfile.dat"); // Event loop. Generate event. Skip if error. List first one. for (int iEvent = 0; iEvent < 100; ++iEvent) { if (!pythia.next()) continue; // Get particles in event ParticleData* particleData = &pythia.particleData; vector<PseudoJet> particles; for (int i = 0; i < pythia.event.size(); ++i) { PseudoJet psJet(pythia.event.px(), pythia.event.py(), pythia.event.pz(), pythia.event.e()); psJet.set_user_info(new ParticleInfo(particleData->name(pythia.event.id()), pythia.event.id())); particles.push_back(psJet); } // Construct jets double R = 0.4; JetDefinition jetDef(antikt_algorithm, R); ClusterSequence clusterSeq(particles, jetDef); Selector select_rapidity = SelectorAbsRapMax(3.0); vector<PseudoJet> jets = select_rapidity(sorted_by_pt(clusterSeq.inclusive_jets())); // Print the jets

 

[LightHero]

#include<iostream>#include<fstream>#include "Pythia8/Pythia.h"#include "fastjet/ClusterSequence.hh"#include "fastjet/PseudoJet.hh"#include "fastjet/Selector.hh"using namespace Pythia8; using namespace std;using namespace fastjet;int main() {// Set up pythiaPythia pythia;pythia.readFile("pythia_pp_events.cmnd");// Initialize pythiapythia.init();// Set up FastJet jet finder double R = 0.4;JetDefinition jet_def(antikt_algorithm, R);// Create an empty vector of pseudojetsvector <PseudoJet> particles;// Event loopfor (int iEvent = 0; iEvent < 10; ++iEvent) { // Generate next event if(!pythia.next()) continue; // Loop over all particles in the event for (int i = 0; i < pythia.event.size(); ++i) { // Require visible particles if(!pythia.event.isFinal()) continue; if(pythia.event.isVisible()) { // Construct a PseudoJet from the complete Pythia particle PseudoJet particleTemp = pythia.event; // Set the user info with PDGID particleTemp.set_user_info(new UserInfo(pythia.event.id())); // Store the PseudoJet in the vector of particles particles.push_back(particleTemp); } } // Create a new instance of a ClusterSequence // and run the clustering algorithm ClusterSequence jetCluster(particles, jet_def); // Extract the jets with pt > 30 GeV double ptmin = 30.0; Selector sel_jets = SelectorPtMin(