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The following plots show the efficiency to tag jets in top quark Monte Carlo samples which have been matched to b quarks, using both the "tight" and "loose" tunes of the SecVtx tagger. The efficiency is obtained by multiplying the tag rate for such jets in the Monte Carlo by our data/MC scale factors of 0.909±0.06 for the tight tagger and 0.927±0.066 for the loose tagger. The bands represent the systematic error on the data/MC scale factors. The decrease in efficiency at high jet Et is due to declining yield of good silicon tracks passing the quality cuts.
The next pair of plots shows the mistag rate for jets resulting from light quark fragmentation. These are have been measured from inclusive jet data.
Click here to see the plots for the previous version of SecVtx.