D0 b-jet identification by means of

Secondary Vertex B-tagging

Verification Plots

Signal
- Top (e+jets) [23-May-2001]
- WH (Wenu) (Hbb) [20-Apr-2001]
- Top [04-Apr-2001]
Background
- W + 4 jets (VECBOS)[23-May-2001]
- QCD [24-Apr-2001]

btag correlations

Given the probability to tag a b-jet by:

e = # b-jets tagged / # total b jets

the probablity per EVENT to tag 1, 2 or more than 1 b-jets, will be given by

P(1 tag)    = e.(1-e) + e.(1-e)
P(2 tag s)  = e^2
P(>=1 tags) = P(1tag) + P(2 tags)

if the process is independent (i.e. tagging the second b-jet is independent from having tagged the first one)

WH results

e = 0.49 +/- 0.01
P(1 tag) = 0.48
P(2 tags) = 0.25
P(>=1 tags) = 0.73

Based on e = 0.49, the tagging probablitity per event for NON-CORRELATED tagging should be:

P(1 tag) = 0.50

P(2 tags) = 0.24

P(>=1 tags) = 0.73

Which is in agreement to what we found.