My analysis on BToDlnu skims                                                                        Kenji Hamano

Last modified : Mar 31, 2005                                              Back to Home


Possible processes

rate    process                                         tag (p*l>1.5)    rate

0.14%    B+ -> D0bar l+ nu                             B- -> X l- nu    5.0%
0.40%    B+ -> D*0bar l+ nu -> D0 l+ nu (1-2 gam)      B- -> X l- nu    5.0%

0.006%   B0 -> D- l+ nu                                B0b -> X l- nu   4.1%
0.013%   B0 -> D*- l+ nu -> D0 l+ nu (pi-)             B0b -> X l- nu   4.1%
0.006%   B0 -> D*- l+ nu -> D- l+ nu (1-2 gam)         B0b -> X l- nu   4.1%
0.006%   B0 -> D- l+ nu                                B0 -> X l+ nu    0.9%
0.013%   B0 -> D*- l+ nu -> D0 l+ nu (pi-)             B0 -> X l+ nu    0.9%
0.006%   B0 -> D*- l+ nu -> D- l+ nu (1-2 gam)         B0 -> X l+ nu    0.9%

         B0 -> D** l+ nu ->

         B+ -> D0 rho+ -> K0b pi- l+ nu pi+ pi0       B- -> X l- nu
         D+ -> (K- pi+) l+ nu                         D- -> X l- nu
         D*+ -> D0 pi+ -> D0 mu+ nu                   D*- -> X l- nu
             -> K- pi0 l+ nu pi+
         D0 -> (K0b pi-) l+ nu                        D0b -> X l- nu
         D*0 -> D0 (1-2 gam) -> K0b pi- l+ nu (1-2 gam)   D*0b -> X l- nu

         Combinatrial background ?
         Mis identification of K, pi and lepton ?


Ntuple production

I applied tag side lepton mementum cut:
      P*_lepton > 1.5 GeV

Location of ntuples at SLAC:
      ~khamano/releases/BToDlnu_16.0.3-physics-1/workdir/rootFiles

Quantities in the ntuple
     DhadType:   D* =>1, D =>0
     DhadMode:   Lund ID of Dhadron (D* or D)
         D_plus => +411
         D_minus => -411
         D0 => +421
         anti_D0 => -421
         D_star_plus => +413
         D_star_minus => -413
         D_star0 => +423
         anti_D_star0 => -423
     DDecayMode:  D0/D+ decay mode
         1 => D0ToKpi
         2 => D0ToK3pi
         3 => D0ToKpipi0
         4 => D0ToKspipi
         5 => DchToKpipi
         6 => DchToKspipi0
         7 => DchToKspi
     trueDlLep:  Lepton from B=>1, otherwise=>0, for MC
     trueDhad:  for MC
     trueDlnu:  for MC
     trueDhadlnu:  for MC
     DhadChrg:  Charge of D hadron (D* or D)
     DChrg:  Charge of D
     tagLeptChrg:  Tag side (Dlnu) lepton charge
     recoLeptChrg:  Recoil side lepton (electron + muon) charge
     recoLepType:  Recoil lepton type: electron -> 1, muon -> 2
     numRecoElec:  number of non-overlap recoil electrons per candidate
     numRecoMu:  number of non-overlap recoil muons per candidate
     numRecoLep:  number of non-overlap recoil leptons per candidate
     DhadMass:  Dhadron (D* or D) mass
     DMass:  D mass
     DhadMom:  Dhadron (D* or D) momentum in CM
     DMom:  D momentum in CM
     tagLeptMom:  Tag side (Dlnu) lepton momentum in CM
     recoLeptMom:  Recoil lepton(electron+muon) momentum in CM
     DLcosBY:  cosTheta_ B-Dl

One BToDlnu candidate consists of one Dhadron and one Lepton.
Dhadron may be D* (D*+, D*-, D*0, or D*0bar) or D (D+, D-, D0, or D0bar).

DhadMode, DDecayMode, tagLepChrg, and recoLepChrg are useful to distinguish the types of processes.
DhadType, DhadChrg, DChrg should be consistent with DhadMode and DDecayMode.


D mass plots:
D0 mass mode-1 plot: OnPeak data vs MC + Off Peak
D0 mass mode-2 plot: OnPeak data vs MC + Off Peak
D0 mass mode-2 plot: OnPeak data vs MC (no Off Peak)
Dch mass mode-5 plot: OnPeak data vs MC + Off Peak
Dch mass mode-5 plot: OnPeak data vs MC (no Off Peak)
yellow = BpBm
magenta = B0B0bar
light blue = ccbar
green = uds
dark green = tautau
blue = OffPeak


D mass plots:
B+B- MC, D0 mass plots
B+B- MC, Dch mass plots
B0B0bar MC, D0 mass plots
B0B0bar MC, Dch mass plots
ccbar MC, D0 mass plots
ccbar MC, Dch mass plots
uds MC, D0 mass plots
uds MC, Dch mass plots
tautau MC, D0 mass plots
tautau MC, Dch mass plots
On Peak Data, D0 mass plots
On Peak Data, Dch mass plots
Off Peak Data, D0 mass plots
Off Peak Data, Dch mass plots
If I select only "trueDhad".
B+B- MC, D0 mass plots - trueDhad
B+B- MC, Dch mass plots - trueDhad

D0 mass plots:
Upper left: D0 -> Kpi      Upper right: D0 -> K3pi
Lower left: D0 -> Kpipi0      Lower right: D0 -> Kspipi
Dch mass plots:
Upper left: Dch -> Kpipi      Upper right: Dch -> Kspipi0
Lower left: Dch -> Kspi      Lower right: all modes


Tag side lepton and Dhadron momentum plots for Bch modes:
B+B- MC, lepton momentum plots
B+B- MC, Dhadron momentum plots
B0B0bar MC, lepton momentum plots
B0B0bar MC, Dhadron momentum plots
These looks almost same, so I selected only D Decay Mode 1
B+B- MC, lepton momentum plots (DMod 1)
B+B- MC, Dhadron momentum plots (DMod 1)
B0B0bar MC, lepton momentum plots (DMod 1)
B0B0bar MC, Dhadron momentum plots (DMod 1)
Now, total number of events are different. And in tag side lepton momentum spectrum, there is a excess of events at around 1.5 GeV in BpBm MC.
ccbar MC, lepton momentum plots (DMod 1)
ccbar MC, Dhadron momentum plots (DMod 1)
On Peak Data, lepton momentum plots (DMod 1)
On Peak Data, Dhadron momentum plots (DMod 1)
Off Peak Data, lepton momentum plots (DMod 1)
Off Peak Data, Dhadron momentum plots (DMod 1)
What's this peak at 5 GeV? Bhabha events?

Upper left: B+ -> D0bar l nu
     (DhadMode==-421) && (tagLeptChrg>0) && (recoLeptChrg < 0)
Upper right: B- -> Do l nu
     (DhadMode==421) && (tagLeptChrg< 0) && (recoLeptChrg>0)
Lower left: B+ -> D*0bar l nu
     (DhadMode==-423) && (tagLeptChrg>0) && (recoLeptChrg< 0)
Lower right: B- -> D*0 l nu
     (DhadMode==-423) && (tagLeptChrg< 0) && (recoLeptChrg>0)

Tag side lepton and Dhadron momentum plots for B0 modes:
B+B- MC, lepton momentum plots
B+B- MC, Dhadron momentum plots
B0B0bar MC, lepton momentum plots
B0B0bar MC, Dhadron momentum plots
Upper left: B0 -> D- l+ nu, reco l-
     (DhadMode==-411) && (tagLeptChrg>0) && (recoLeptChrg<0)
Upper right: B0bar -> D+ l- nu, reco l+
     (DhadMode==411) && (tagLeptChrg<0) && (recoLeptChrg>0)
Lower left: B0 -> D*- l+ nu, reco l-
     (DhadMode==-413) && (tagLeptChrg>0) && (recoLeptChrg<0)
Lower right: B0bar -> D*+ l- nu, reco l+
     (DhadMode==413) && (tagLeptChrg<0) && (recoLeptChrg>0)

Tag side lepton and Dhadron momentum plots for B0 oscillated modes:
B+B- MC, lepton momentum plots
B+B- MC, Dhadron momentum plots
B0B0bar MC, lepton momentum plots
B0B0bar MC, Dhadron momentum plots
Upper left: B0 -> D- l+ nu, reco l+
     (DhadMode==-411) && (tagLeptChrg>0) && (recoLeptChrg>0)
Upper right: B0bar -> D+ l- nu, reco l-
     (DhadMode==411) && (tagLeptChrg<0) && (recoLeptChrg<0)
Lower left: B0 -> D*- l+ nu, reco l+
     (DhadMode==-413) && (tagLeptChrg>0) && (recoLeptChrg>0)
Lower right: B0bar -> D*+ l- nu, reco l-
     (DhadMode==413) && (tagLeptChrg<0) && (recoLeptChrg<0)