JetChunk certification summary - For floats, difference TMB root- tuple 10**- 3 - An exception is variable EMF where difference is 5.10**- 3 - Problem with n90 ?
Fake jets in p13.02.00 and p11.13.00 Lot of fake jets in p11.13.00 => new quality cut : f90<- 0.5CHF + 0.8 What is the situation in p13.02.00 (where ZS : 2.5 ? - Criterion : f90 if high =>fake jet if low => good jet
in p11.13.00 data CHF Cone R=0.7 Cone R=0.5 N1 good jets N2 fake jets N2/N1 33 N2/N1 60 N1 N2
in p13.02.00 data N2/N1 16 Cone R=0.5 Cone R=0.7 N2/N1 30 N2 N1
The number of fake jets is reduced by a factor of 2 in p13.02.00, where we have 2.5 of zero suppression (instead of 2.1 in p11.13.00) Fake jets in p13.02.00 and p11.13.00 summary
Current status of the algorithms : Jets are constructed with a list of positive energy towers. These towers are made of positive and negative energy cells. What happens if we remove corresponding layers (15, 16, 17) ? (input of the algorithm : calorimeter towers without CH layers) Not consistent with Met calculation, which is done with towers > 200MeV or cells > 100MeV Coarse Hadronic may be responsible for fake jets What happens if we keep only positive cells in jets ? Effect of coarse hadronic layers and negative cells on jets
Cone R=0.5 N2/N1 7.5 N2/N1 16 N1 N2 N1 N2 N1 N2/N1 7.5 Current algo Without CH layers and neg cells Without CH layers Cone R=0.7 N2 N1 N2 N1 N2 N1 N2/N1 14 N2/N1 30 N2/N1 14 Current algo Without CH layers and neg cells Without CH layers
Summary => reconstruction without CH layers reduces the number of fake jets by a factor of 2