PARTICLE IDENTIFICATION WITH RICH
RICH as a particle identification device - it does clear your signals!
An example: phi->KK, no PID cut (a), hard RICH likelihood cut on both kaons (b).
Reprocessing 2, RITER, soft.
Reprocessing 2, RITER, medium.
Reprocessing 2, RITER, hard.
Reprocessing 2, RISE, cut in the r2p2 plot.
Reprocessing 3, RITER, soft.
Reprocessing 3, RITER, medium.
Reprocessing 3, RITER, hard.
Reprocessing 3, new algorithm, selection criteria and efficiency under study.
RICH as a particle identification device - how to do it
A three level identification tool
comes from Marko Staric. It allows you to choose the identification
level (three levels, soft, medium and hard cut on the likelihoods as given by the
RITER algorithm) according to your needs.
The routines are available in the arte library.
Alternatively, the likelihoods calculated with the ring search package
RISE can be used to
make PID selections for the reprocessing 2 data. In the reprocessing 3, a
new algorithm replaced RISE.
RICH as a particle identification device - how well does it work
Efficiencies and fake probabilities for various selection
criteria were determined by using
Ks -> pi+ pi-, phi-> K+ K-, Lambda-> p pi- decays. A complete set of plots can be found
Plots on the diagonal show the efficiency (e.g. p->p),
plots left or right to the diagonal show the mis-identification probability (e.g. p->K).
Individual efficieny/fake probability plot matrices:
Examples from reproc. 3: Efficiency/fake probability plots for the medium (open circles) and hard (full circles) identification levels.
Daniel Peralta has provided a user friendly
which combines likelihood values
from both reconstruction algorithms, the track based and the stand-alone.
More information on the particle identification alogorithms