D0root version v7.1

• Change Log
• Instructions
• Results
• Known Problems
• dimuon B-tuples

Change Log

o Brad Abbott and Phil Gutierrez introduced several modifications and bug fixes in BphysicsAnalyis class which give a significant improvement in our B+ signal:

• Changed minimum track Pt for J/Psi finder from 2.0 to 1.5 and max. vertex mass to 4.0
• Deleted line nentries=1000;
• ** bug fix **
  Changed
  float massc1 = MassConstraint1(vtx,B); to
  float massc1 = MassConstraint1(*vtx,B);
• Changed
  float MassConstraint1(D0Vertex *jpsi, D0Vertex* BpsiK) to
  float MassConstraint1(D0Vertex jpsi, D0Vertex* BpsiK)
  and
  TLorentzVector* psi = (TLorentzVector*) & jpsi; //constrained momentum
• Changed definition of massc2 from
  float massc2 = MassConstraint2(vtx,B); to a new one based on VertexMassConstraint algorithm.
  massc2 is the "correct" mass constraint and should be used for analysis. massc1 is only left in for "historical purposes"
• changed
  bB.khits[nBs] = kaon-> SmtHits(); to
  bB.khits[nBs] = kaon-> SmtHits() + kaon->SmtFdiskHits();
  So it is consistent with value used in Finders.
• Changed "zeroing" of arrays from 0 to -9999 since some variables can have a legitimate value of 0
• D0Muon.cpp: Changing definition of muon quality. Allowing nseg >=0 muons.
• Use -g option for compilation - Don Lincoln.
• Use latest EMcandidate code.

Instructions (TMBTree)

//Create release area
//----------------------------------
newrel -t p14.01.00 mydir
cd mydir
d0setwa


//Install packages
//----------------------------------
addpkg d0root_analysis v00-07-13 
addpkg d0root_btag v00-07-10

addpkg jetcorr v04-00-01
addpkg em_util v00-02-78                
addpkg emcandidate v00-01-05                

//Generate TMBTreeClasses file
//----------------------------------
ln -s /d0dist/dist/releases/p14.01.00/tmb_analyze/macros/ macros
cp macros/MakeTMBTreeClasses_so.C .
root -q MakeTMBTreeClasses_so.C


//Compile jetcorr package
//----------------------------------
cd jetcorr
root -q MkRootLib.C 
cd ../

//Compile em_util package
//----------------------------------
gmake em_util.all EMUTIL_SHARED=1
gmake emcandidate.all EMUTIL_SHARED=1


//Link em_util package
//----------------------------------
cd d0root_btag
ln -s ../em_util em_util
cd ../


//Compile d0root packages
//----------------------------------
gmake d0root_analysis.all
gmake d0root_btag.all

Run analysis code

cd d0root_btag
root runBphysicsAnalysis_TMBtree.C

This command will create an instance of the class BphysicsAnalysis called "b". To see the list of available methods please look at d0root_btag/analysis/BphysicsAnalysis.h

To create a B-rtuple with information about J/Psi, Phi and B vertices, do:

    b->Process_diMuons("myOutputFileName", all_muons, muon_pt, muon_quality);

• "myOutputFileName" is the name of the output root tree.
• all_muons is a boolean variable indicating which tracks are going to be vertexed: true: all tracks; false only tracks matched to muons. By default all_muons = false.
• muon_pt is the minimum global muon pT in GeV/c, by default 1.5 GeV/c.
• muon_quality is the minimum quality, by default 0.

  The Muon quality definition is defined in d0root_analysis/objects/Muon.cpp:

• muon_quality = 0: nseg >= 0
• muon_quality = 1: nseg >= 1
• muon_quality = 2: 1 + centralrank==1
• muon_quality = 3: 2 + whits_a > 1 && whits_bc > 2 && shits_a > 0 && shits_bc > 0
• muon_quality = 4: 3 + nseg >= 3

To open the ROOT tuple and plot the invariant J/Psi invariant mass and lifetime do:

 root myOutputFileName.root
 tree->Draw("PSI.mass","PSI.mass>2 && PSI.mass<4")
 tree->Draw("PSI.lifetime","PSI.mass>2.8 && PSI.mass<3.3")

Back to Vertex fitting and finding in ROOT page

Results

B -> JPsi K candidates (thanks to Christos)

B -> JPsi K candidates (thanks to Christos)

di-muon Invariant mass (Thanks to Brad)

Known Problems

• Jets matched to EM objects are not removed.
• Muo-Candidate is not implemented in this version. Muons are read from the standard Muon branch in the TMBTree.
• Muons are selected with the pT given by the muon object instead of its matched track.

dimuon B-tuples

/work/creek-clued0/abbott/vertexing/p1308_v7/d0root_btag/AA_reprocessing_latest.root

Please send questions/comments/improvements/modifications to

Back to Vertex fitting and finding in ROOT page