Sequential recombination algorithm for jet clustering and background subtraction

Jeff Tseng, Hannah Evans

We investigate a new sequential recombination algorithm which effectively subtracts background as it reconstructs the jet. We examine the new algorithm's behavior in light of existing algorithms, and we find that in Monte Carlo comparisons, the new algorithm's robustness against collision backgrounds is comparable to that of other jet algorithms when the latter have been augmented by further background subtraction techniques.


The algorithm is available as a Fastjet contribution as of 4 June 2013.

Sample code extract:


  #include <vector>
  #include "fastjet/contrib/ScJet.hh"
  using namespace std;
  using namespace fastjet;


  vector<PseudoJet> cells; // input pseudo-jets


  JetDefinition::Plugin* scplugin = new fastjet::contrib::ScJet(1.0);
  JetDefinition jet_def(plugin);
  ClusterSequence cs(cells, jet_def);
  vector<PseudoJet> jets = sorted_by_pt(cs.inclusive_jets());


14 August 2013