Description of BchToD0KAll and BchToD0KstarAll skims

Last update: Oct 31, 2005 -- V. Azzolini For R18
Last update: Feb 9, 2005 -- Stephen Schrenk For R16
Last update: Sep 15 -- Wouter Verkerke

This web page documents the BchToD0KAll and BchToD0KstarAll skims for the CM2 skim production. This pages describes the composition of the skims in terms of tagsbits and SimpleComposition/CompositionSequences lists and cuts and gives an estimate of the selection efficiency and selection rate on various data and MC samples

Description of skims and composition in terms of tag bits

Skim BchToD0KAll contains a large number of B+/- --> D(*)0(bar)K+/- decays with D0 decaying into the 'mainstream' decay modes as well as a variety of rare CP-odd and CP-even eigenstate. The D*0 is reconstructed in both the D*0 --> D0 pi0 and D*0 --> D0 gamma modes. This skim includes doubly Cabibbo suppressed decays (B- --> D(*)0bar K-). No PID cuts are applied to the bachelor kaon for the D0 CP eigenstate decays to facilitate the measurement of BF(B- to D0CP K-)/BF(B- to D0CP pi-). The D0 mass window is 70 MeV, except for the D0->KsPiPi and D0->KsPiPiPi0 channels, which is 40 MeV. For R18 new tag bits have been added specifically for D0->multibody (Dalitz) decays, used for the D0(Dalitz)K gamma analysis.  In this case, the D0 mass window for all channels is 70 MeV.

The skim is defined as the 'or' of the following tag bits:
These tag bits are created by TagFromList from the following lists
which are also persisted in the skim. The definition of the skim and the lists of candidates that are persisted are specified in FilterTools/BchToD0KAll.tcl

Skim BchToD0KstarAll contains a large number of B+/- --> D(*)0(bar)K*+/- decays with D0 decaying into the 'mainstream' decay modes as well as a variety of rare CP-odd and CP-even eigenstate decays. The D*0 is reconstructed in both the D*0 --> D0 pi0 and D*0 --> D0 gamma modes. The K*+/- is reconstructed in the modes K*+/- --> K*+/- pi0 and K*+/- --> KS pi+/-. This skim includes doubly Cabibbo suppressed decays (B- --> D(*)0bar K-). The D0 mass window is 70 MeV, except for the D0->KsPiPi and D0->KsPiPiPi0 channels, which is 40 MeV.
For R18 new tag bits have been added specifically for D0->multibody (Dalitz) decays, used for the D0(Dalitz)K gamma analysis.  In this case, the D0 mass window for all channels is 70 MeV. 

The skim is defined as the 'or' of the following tag bits: These tag bits are created by TagFromList from the following lists
which are also persisted in the skim. The definition of the skim and the lists of candidates that are persisted are specified in FilterTools/BchToD0KstarAll.tcl

All tag bits are defined in EventTagTools/TagProdCreateSequence.tcl

Description of tag bits in terms of CompositionSequences lists and cuts

SMS->LH notapion
List Composistion List of D0 decays included Summary of applied cuts [changes w.r.t last BReco skim]

Skim Efficiency estimate

To validate the skims we have done studies over the efficiency selection rate results at  http://ific.uv.es/~babar/TagBit_test.html

For the test, we run over 10000 events from  AllEvents-Run4-OnPeak-R18.tcl working with release 18.3.1b.
The skim rate is calculated over the total events 10000. The number of hadronic events passing FilterBGFMultiHadron is 2912 events.
Table 1 shows the skim rate for the test of the new tag bits, where new, old and all (new + old).
Only new tag bits are tested in Table 2, where the rate for all the channels is shown.
We made a detailed study of the skim rate for D0->kspipipi0, for each considered B decay.