Random Cluster Subtraction

Random Cluster Subtraction

The histograms below show the radial distance (&radic(&Delta&eta2 + &Delta&phi2)) between primary seed and associated tracks in data (red) and mixed events (black) histograms. For the mixed event background, a primary seed is taken from an event and mixed with associated tracks from other events.


dN/dR - minimum secondary seed - 2.0 GeV
Because of the relatively low secondary seed cut, there are a good number of random clusters (black histogram) as background.



dN/dR - minimum secondary seed - 3.0 GeV
Increasing the secondary seed cut definitely enhances the signal (red histogram) over the random clusters (black histogram).

dN/dR - minimum secondary seed - 4.0 GeV
The signal (red histogram) is further enhanced over the random clusters (black histogram) by increasing the secondary seed cut from 3 to 4 GeV.




The distribution of multi-hadron triggers as a function of pT,jet pT,associated, and &Delta&phi . The plot on the left is for secondary seed tracks with an R < 0.3. The plot in the middle is for secondary seed tracks with 0.8 < R < 1.2. The plot on the right is for secondary seed tracks with 0.8 < R < 0.845.