SignalFreeBackgroundEstimator is part of the fastjet-contrib project.

The SignalFreeBackgroundEstimator class estimates pileup pT density (rho) with lower dependence on the signal particles, as described in

   Pileup density estimate independent on jet multiplicity
   Peter Berta, Juraj Smiesko, Martin Spousta
   arXiv:2304.08383

The code example.cc illustrates how to use the class on individual jets.
It can be built using

    make example

example.cc makes use of an input datafile which is provided in the
/data directory, and it should be run with

   ./example < ../data/Pythia-Zp2jets-lhc-pileup-1ev.dat

The expected output can be found in example.ref