Opposite Side Kaon Tagger
This web page summarizes the performances of an Opposite Side Kaon Tagger, evaluated over a sample of b semileptonic decays. It is based upon 355 pb-1 of data triggered with the dedicated l+SVT trigger.
The results have been approved as of April 13, 2006.
The algorithm exploits both a combined TOF+dE/dx PID technique and the vertexing information to tag the flavour of the accompanying b from the charge of a Kaon displaced from the PV. The information of the OS b direction is also inferred from track-based jets in an event.
The final peformances we measure are:
- &epsilon = 18.11 ± 0.07 (stat.) %
- &epsilon D2 = 0.229 ± 0.016 (stat.) ± 0.001 (syst.) %
- effective D = 11.09 ± 0.88 (stat.) %
The performances are evaluated after a binning procedure of the Dilution on two selective variables: the fraction of the OS b-jet momentum carried by the Kaon and its Impact Parameter significance.
If not binned, the final performances are:
&epsilon D2 = 0.176 ± 0.014 (stat.) ± 0.001 (syst.) %
effective D = 9.9 ± 0.9 (stat.) %
A more detailed summary of the results can be found here:
Below are the eps and gif versions of all figures meant for downloads.
- Figure 1: Impact Parameter significance of the tagging candidates (.eps)(.gif)
- Figure 2: Comparison of Impact Parameter significance of the tagging candidates in MC (Pythia b - anti-b semileptonic sample) and data (.eps)(.gif)
- Figure 3: Combined Likelihood Ratio of the tagging candidates in the Kaon hypothesis(.eps)(.gif)
- Figure 4: MC distribution of the various contributions to the Combined Likelihood Ratio in the Kaon hypothesis(.eps)(.gif)
- Figure 5: Tagging track multiplicity (.eps)(.gif)
- Figure 6: MC distribution of the fraction of the Jet Momentum carried by the Kaon (.eps)(.gif)
- Figure 7: Binning of the dilution for the different tag classes with the fraction of Jet Momentum and the absolute I.P. significance (.eps)(.gif)