2008.11.18 Cluster isolation cuts: 2x1 vs. 2x2 vs. 3x3

Ilya Selyuzhenkov November 18, 2008

Data sets:

2x1, 2x2, and 3x3 clusters definition:

  • 3x3 cluster: tower energy sum for 3x3 patch around highest tower
  • 2x2 cluster: tower energy sum for 2x2 patch
    which are closest to 3x3 tower patch centroid.
    3x3 tower patch centroid is defined based
    on tower energies weighted wrt tower centers:
    centroid = sum{E_tow * r_tow} / sum{E_tow}.
    Here r_tow=(x_tow, y_tow) denotes tower center.
  • 2x1 cluster: tower energy sum for high tower plus second highest tower in 3x3 patch
  • r=0.7 energy is calculated based on towers
    within a radius of 0.7 (in delta phi and eta) from high tower

Cuts applied

all gamma-jet candidate selection cuts except 3x3/r=0.7 energy isolation cut

 

Results for 2x1, 2x2, and 3x3 clusters

  1. Energy fraction in NxN cluster in r=0.7 radius
    2x1, 2x2, 3x3 patch to jet radius of 0.7 energy ratios
  2. Yield vs. NxN cluster energy fraction in r=0.7
    For a given cluster energy fraction yield is defined as an integral on the right
  3. Efficiency vs. NxN cluster energy fraction in r=0.7
    For a given cluster energy fraction
    efficiency is defined as the yield (on the right)
    normalized by the total integral (total yield)

 

Efficiency vs. NxN cluster energy fraction in r=0.7

Efficiency vs. NxN cluster energy fraction in r=0.7

Figure 1b: 2x1/0.7 ratio

Figure 2b: 2x2/0.7 ratio

Figure 3b: 3x3/0.7 ratio

Figure 4b: 3x3/0.7 ratio but only using towers which passed jet finder threshold

Energy fraction in NxN cluster within r=0.7 radius

Energy fraction in NxN cluster within r=0.7 radius

Figure 1a: 2x1/0.7 ratio

Figure 2a: 2x2/0.7 ratio

Figure 3a: 3x3/0.7 ratio

Figure 4a: 3x3/0.7 ratio but only using towers which passed jet finder threshold

Yield vs. NxN cluster energy fraction in r=0.7

Yield vs. NxN cluster energy fraction in r=0.7

Figure 1c: 2x1/0.7 ratio

Figure 2c: 2x2/0.7 ratio

Figure 3c: 3x3/0.7 ratio

Figure 4c: 3x3/0.7 ratio but only using towers which passed jet finder threshold