1/7 Andrew Powell CP Working Group Meeting - Friday, 7 th September 2006 D*  D(4h)  DC06 Preselection

2/7 Motivations Reasons for this D*  D(4h)  selection: B  D(4h)K : Amplitude and phase information from D decays for 4- Body Dalitz Fitting Important Background Category for B  D(4h)K HLT Calibration Methodology: Extract signal events from the inclusive B 0  (D*  D  )  tapes Run over bbar events to develop preselection cuts and use 2-Body preselections as a guide

3/7 D* - Mass -   < - pT > -sIPS > -  M(D*,D) < - D*-D Cos  > - D*-D IPS < D 0 - Mass -   < - p > - pT > - Flight sig > - sIPS > Bachelor  -p > - pT > - sIPS > D 0 Daughters - p > - pT > - sIPS > Preselection Cuts 60 MeV GeV MeV GeV 100 MeV MeV GeV 2.75 GeV {4.0(K), 2.0(  )} GeV {400(K), 125(  )} MeV 2.0

4/7 D* - D0 Mass Diff MeV D0 Mass MeV D* Mass Plots K  Signal bbar BG Mass plots for D*, D 0 &  M(D*,D0) with preselection cuts applied MeV PreSel Cut

5/7 Preselection Statistics MCEffBuilder Info Reconstrucible & Reconstructed Truth Matched Events Passing PreSel Signal A comparison with the results from Patrick Spradlin’s 2-Body Preselection Inclusive B d  D *  Events Processed 304, ,500 Decays of Interest Gen. 14,456 28,993 1,891 1, Br(K  ) ~ 2 X Br(K  ) Background – 100K Initial Initial Background Selection (Loosest Possible Cuts) Background Events Passing PreSel ? 2, /100K ~ 1/862 A little high

6/7 Yield Estimates S = L INT.  bb. 2. f q.  TOT. Br VIS L INT = 2 fb -1  bb = 500  b 1 x bb-bar/year Br(D  K  ) = 3.8x10 -2 Br(B d  D*  ) = 2.76x10 -3 Br(D*  D  ) = 6.8 x10 -1 Br(K  ) = 7.10 x  L0/SEL =  L1/L0 =  TRIG/SEL = 0.33  TOT (K  = 856 x x  TRIG/PRE-SEL = 6.75 x ,456 S(K  ) = 383,171 events / year

7/7 Br(D  K  ) = 7.46x10 -2 Br(B d  D*  ) = 2.76x10 -3 Br(D*  D  ) = 6.8x10 -1 Br(K  ) = 1.39 x  L0/SEL = 0.45  L1/L0 = 0.79  TRIG/SEL = 0.36  TOT (K  = 341 x x  TRIG/PRE-SEL = 1.47 x ,993 S(K  ) = 163,380 events / year Yield Estimates