Update on noisy jets with cone algorithm p13'02

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Update on noisy jets with cone algorithm (p13.02)
Jet/Met meeting 12/04/2002
Emmanuel Busato
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Goal modify the input of the algorithm (tower
list) to see the effect on the
number of fake jets.
Algo
Jet list
Tower list
3 modifications - remove CH layers
in tower list - include negative towers in
tower list - remove negative cells in tower
list
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Run 167257 (19 reco files, 33 661 events) Jet
selection standard ID cuts ? 0.05 lt EMF lt
0.95 ? CHF lt 0.4 ? n90 gt 1 ? HotF lt
10 no trigger selection the number of fake
jets is estimated with a double gaussian fit on
f90 distribution Nbad number of fake
jets Ngood number of good jets
RNbad/(NgoodNbad)
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Cone R0.5
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Cone R0.7
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Summary
? Coarse hadronic layers are responsible for a
lot of fake jets (? 1/2) ?
Introduction of negative energy towers increases
the number of fake jets
(noise in coarse hadronic cells) What happens
when we combine these two modifications? (remove
coarse and keep negative towers) ?
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No CH layers, negative towers included
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What about negative cells