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//----------------------------------------------------------------------
/// \file example_isd.cc
///
/// This example program is meant to illustrate how the
/// fastjet::contrib::IteratedSoftDrop class is used.
///
/// Run this example with
///
/// \verbatim
/// ./example_isd < ../data/single-event.dat
/// \endverbatim
//----------------------------------------------------------------------
// $Id: example_isd.cc 1018 2017-04-25 13:14:21Z jthaler $
//
// Copyright (c) 2017, Jesse Thaler, Kevin Zhou
// based on arXiv:1704.06266 by Christopher Frye, Andrew J. Larkoski,
// Jesse Thaler, Kevin Zhou
//
//----------------------------------------------------------------------
// This file is part of FastJet contrib.
//
// It is free software; you can redistribute it and/or modify it under
// the terms of the GNU General Public License as published by the
// Free Software Foundation; either version 2 of the License, or (at
// your option) any later version.
//
// It is distributed in the hope that it will be useful, but WITHOUT
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
// or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
// License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this code. If not, see <http://www.gnu.org/licenses/>.
//----------------------------------------------------------------------
#include <iostream>
#include <sstream>
#include <sstream>
#include <iomanip>
#include <cmath>
#include "fastjet/ClusterSequence.hh"
#include "IteratedSoftDrop.hh" // In external code, this should be fastjet/contrib/IteratedSoftDrop.hh
using namespace std;
using namespace fastjet;
// forward declaration to make things clearer
void read_event(vector<PseudoJet> &event);
//----------------------------------------------------------------------
int main(){
//----------------------------------------------------------
// read in input particles
vector<PseudoJet> event;
read_event(event);
cout << "# read an event with " << event.size() << " particles" << endl;
// first get some anti-kt jets
double R = 0.5;
JetDefinition jet_def(antikt_algorithm, R);
double ptmin = 200.0;
Selector pt_min_selector = SelectorPtMin(ptmin);
vector<PseudoJet> jets = pt_min_selector(jet_def(event));
// Determine optimal scale from 1704.06266 for beta = -1
double expected_jet_pt = 1000; // in GeV
double NP_scale = 1; // approximately Lambda_QCD in GeV
double optimal_z_cut = (NP_scale / expected_jet_pt / R);
// set up iterated soft drop objects
double z_cut = optimal_z_cut;
double beta = -1.0;
double theta_cut = 0.0;
contrib::IteratedSoftDropSymmetryFactors isd(beta, z_cut, theta_cut, R);
contrib::IteratedSoftDropSymmetryFactors isd_ee(beta, z_cut, theta_cut, R, contrib::IteratedSoftDropSymmetryFactors::E_theta);
contrib::IteratedSoftDropMultiplicity nsd(beta, z_cut, theta_cut, 0.0, R);
contrib::IteratedSoftDropMultiplicity nsdk0p5(beta, z_cut, theta_cut, 0.5, R);
contrib::IteratedSoftDropMultiplicity nsdk1(beta, z_cut, theta_cut, 1.0, R);
contrib::IteratedSoftDropMultiplicity nsdk2(beta, z_cut, theta_cut, 2.0, R);
cout << "---------------------------------------------------" << endl;
cout << "Iterated Soft Drop" << endl;
cout << "---------------------------------------------------" << endl;
cout << endl;
cout << "Computing Symmetry Factors with:" << endl;
cout << " " << isd.description() << endl;
cout << " " << isd_ee.description() << endl;
cout << endl;
cout << "Computing Soft Drop Multiplicities with :" << endl;
cout << " " << nsd.description() << " (optimal at LL)" << endl;
cout << " " << nsdk0p5.description() << endl;
cout << " " << nsdk1.description() << endl;
cout << " " << nsdk2.description() << endl;
cout << endl;
for (unsigned ijet = 0; ijet < jets.size(); ijet++) {
cout << "---------------------------------------------------" << endl;
cout << "Processing Jet " << ijet << endl;
cout << "---------------------------------------------------" << endl;
cout << endl;
cout << "Jet pT: " << jets[ijet].pt() << " GeV" << endl;
cout << endl;
// Run full iterated soft drop and show the symmetry factors
vector<double> syms = isd(jets[ijet]);
cout << "Symmetry Factors (pt_R measure, beta=" << beta << ", z_cut=" << z_cut << "):" << endl;
for (unsigned i = 0; i < syms.size(); i++){
cout << syms[i] << " ";
}
cout << endl;
cout << endl;
// Alternative version with e+e- measure
vector<double> syms_ee = isd_ee(jets[ijet]);
cout << "Symmetry Factors (E_theta measure, beta=" << beta << ", z_cut=" << z_cut << "):" << endl;
for (unsigned i = 0; i < syms_ee.size(); i++){
cout << syms_ee[i] << " ";
}
cout << endl;
cout << endl;
cout << "Soft Drop Multiplicities (pt_R measure, beta=" << beta << ", z_cut=" << z_cut << "):" << endl;
cout << "kappa = 0: " << nsd(jets[ijet]) << endl;
cout << "kappa = 0.5: " << nsdk0p5(jets[ijet]) << endl;
cout << "kappa = 1: " << nsdk1(jets[ijet]) << endl;
cout << "kappa = 2: " << nsdk2(jets[ijet]) << endl;
cout << endl;
}
return 0;
}
//----------------------------------------------------------------------
/// read in input particles
void read_event(vector<PseudoJet> &event){
string line;
while (getline(cin, line)) {
istringstream linestream(line);
// take substrings to avoid problems when there are extra "pollution"
// characters (e.g. line-feed).
if (line.substr(0,4) == "#END") {return;}
if (line.substr(0,1) == "#") {continue;}
double px,py,pz,E;
linestream >> px >> py >> pz >> E;
PseudoJet particle(px,py,pz,E);
// push event onto back of full_event vector
event.push_back(particle);
}
}

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