d0root version v6.1

• Change Log
• Instructions
• Results
• Known Problems

Change Log

• Memory leak fix in V0Finder - Kin Yip
• New Muon quality definition (d0root_analysis/objects/Muon.cpp) - Ariel
• One more than 1 primary vertex is found, the one closest in Z to the pT averaged di-muon Z position is chosen. - Ariel
• Require muon nseg > 0 instead of nseg > 2 (d0root_analysisTMBReadEvent.cpp) Brad/Vivek/Ariel.
• Require tracks with at least 1 SMT Barrel hit for Primary and V0 vertex reconstruction (d0root_btag/analysis/BphysicsAnalysis.cpp) - Ariel
• Use standard method in TMBTree to get the track matched to nseg > 0 muons (d0root_analysisTMBReadEvent.cpp) - Stefan/Vivek/Brad/Ariel.
• Add branch with PSI candidates using 4-momentum 2-track combinations to study vertex efficiency - Ariel.
• Add number of fdisk hits in PSI Branch. - Ariel.

Instructions (TMBTree)

//Create release area
//----------------------------------
newrel -t pXX.XX.XX mydir
cd mydir
d0setwa


//Install packages
//----------------------------------
addpkg d0root_analysis v00-06-16
addpkg d0root_btag v00-06-16

addpkg jetcorr v04-00-01
addpkg em_util v00-02-69                

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

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


//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 GeV/c.
• muon_quality is the minimum quality, by default 2.

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

• muon_quality = 1: centralrank==1 && nseg >= 1
• muon_quality = 2: 1 + whits_a > 1 && whits_bc > 2 && shits_a > 0 && shits_bc > 0
• muon_quality = 3: 2 + 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.lifetime!=0 && PSI.mass>2.8 && PSI.mass<3.3")

Back to Vertex fitting and finding in ROOT page

Results

di-muon Invariant mass (opposite sign charged tracks)

di-muon Invariant mass (opposite sign charged tracks)

Lifetime (correction factor = 0.73)

B -> JPsi K candidates

Known Problems

• Muo-Candidate is not implemented in this version. Muons are read from the standard Muon branch in the TMBTree.
• About 30% of J/Psi events have either no found primary vertex or a low multiplicity vertex. One way to recover these events is to use the run averaged vertex instead of the event vertex.

Back to Vertex fitting and finding in ROOT page