1. Kinematic Background

Rej_TD=300,   Rej_PV=160

Km2 tail (1st bifur.)	4.5+/-3.0/(Rej_TD-1)	0.015+/-0.010
Km2 tail (2nd bifur.)	5.8+/-0.5/(Rej_TD-1)	0.019+/-0.002
Km2 band(1st bifur.)	3.0+/-3.0/(Rej_TD-1)	0.010+/-0.010
Km2 band(2nd bifur.)	3.2+/-1.0/(Rej_TD-1)	0.011+/-0.003
Kp2 (1st bifur.)	3.0+/-3.0/(Rej_PV-1)	0.019+/-0.019
Kp2(2nd bifur.)	1.2+/-0.3/(Rej_PV-1)	0.008+/-0.002

   Bkg(Km2) = 0.030 +/- 0.004 (stat.) +/- 0.005 (sys.)
  Bkg(Kp2)  = 0.008 +/- 0.002 (stat.) +/- 0.011 (sys.)

  Total kinematic bakcground: 0.038 +/- 0.004 (stat.) +/- 0.012 (sys.)

  1) The background levels stay unchanged from the previous pass2 ntuples to the
      latest pass2 ntuple.
 2) The quoted systematic uncertinties account for the difference between 1st and
      2nd bifurcations.
 3) The background level is almost the same as that in 1998 data when being
     normalized to the same Kblive.

2. What is left before we go to 2/3 sample?
 
 1) Justify the TD rejection
    Skim1: Beam cuts + Inv. PV cuts + Kin cuts (no RS dE/dx and scattering cuts)
                                    N_km2 (Before TD cut)
                   Ratio1 = -------------------------------
                                    N_km2 (after TD cut)
         We expect: Ratio1 ~ Rej_TD,  
  
 2) Justify the PV rejection
     Skim2: Beam cuts + Inv. TD cut + Kin cuts (no RS dE/dx and scattering cuts)
                                    N_kp2 (before PV cut)
                   Ratio2 = -----------------------------
                                    N_kp2 (after PV cut)
     We expect: Ratio2 ~ Rej_PV