BPF Wiki


Break Point Fitter (hereafter BPF) is a suite of different packages. It contains a particle tracker, a muon PID generator, and an event level energy estimator (currently under development.)


The tracker fits FuzzyK prongs based on a Coulomb multiple scattering model:
  • docDB 12241: Intro to the tracking algorithm.
  • docDB 13201: A more picture-based intro to the tracking method.
  • docDB 12173: A more technical intro that walks through some of the code.
  • docDB 14249: Michael's dissertation - a lengthy read, but just skip to the end of the reco chapter...
The muon PID generator calculates a muon score for each track made under the muon assumption. Similar in spirit and implementation to RemId (hereafter remid - because I can't be bothered with its weird cAps sTylE), it uses a computed dE/dx log-likelihood, a track fit X^2, track length, and ratio of hits on the track to hits in the original prong:
  • docDB 12403: Intro to the BPF dE/dx calculator.
  • docDB 12694: Summary of the whole BPF dE/dx log-likelihood calculation method.
  • docDB 14249: Michael's dissertation (again...)
  • docDB 16575: Summary of work done by Jonathan Davies to retrain the muon PID as a BDT.
A few studies have been done to compare the performance of the BPF tracker and muon PID vs. the Kalman/RemId path:
  • docDB 18348: A first look at muon finding efficiency and track completeness and purity.
  • docDB 18729: A second look at muon finding efficiency and track energy resolution.
Energy Estimator Stuff...:
  • docdb 18714: First pass at a numu energy estimator using PID by truth and BPF energy.


Current Primary Developers/Authors:
Michael Baird
Erica Smith
Mark Messier

Contact us if you are interested in joining the BPF efforts! There is also a NOvA slack channel for BPF development and issues (#bpf).

BPF How To's:

Checking and Updating the dE/dx Tables
Retraining the muon PID

Notes pages:

Michael's Notes

Erica's Notes

Mark's Notes

Energy Estimator to Do List

Trimming and revamping BPF in the CAFs


Failed Plots Gallery