D0root version v9.2

• Change Log
• Instructions
• Links
• Known Problems

Change Log

Vertexing

• Adaptive Robust Vertex Fitting

  New approach for vertex fitting resulting in the following improvements, with respect to the Kalman Filter, in Zbb Monte Carlo samples:

  • Resolution: 18um --> 14um.
  • Pull: 1.43 --> 1.04.
  • Non-Gaussian tails: 48% --> 8%.

  The method is described in the following agenda

  Here is an example of use:

  // Instantiate // -------------- double parameters[2] = {4,3}; AdaptivePrimaryVertexFinder* pvFinder = new AdaptivePrimaryVertexFinder("fermi",parameters); // Find vertices // -------------- TObjArray tracks; _readEvent->getTracks(tracks); pvFinder->FindVertices(tracks); TObjArray pVertices = pvFinder->GetVertices();

Don Lincoln changes

d0root_analysis/objects/D0Jet.cpp & d0root_analysis/objects/D0Jet.h
Added to the D0Jet object three additional fields...the jet energy scale
correction and both the statistical and systematic error.  This necessitated
a change in the D0Jet constructor.  In addition, methods were added to
access this information.  I also changed the internal variable "_P".  It had
been the uncorrected jet 4-momentum.  In recent versions, it was simply the
corrected 4-momentum.  I reverted it to the raw 4-momentum and renamed it as
"_Raw_P".   Finally, I slightly modified the print method.



d0root_analysis/objects/D0Particle.cpp &
d0root_analysis/objects/D0Particle.h
Added the method PtRel_Light, which is similar to the original PtRel method.
The difference is that in PtRel, you find a Pt relative to the combined axis
of the two input objects (say a jet and a muon).  In PtRel_Light, the
supposition is that you are looking at the PtRel between a jet and a track
(and definitely not a muon).  Consequently, the track energy is already
found in the jet and so the correct axis to use is the jet axis and not the
jet+muon axis.



d0root_analysis/objects/D0JetInfo.cpp & d0root_analysis/objects/D0JetInfo.h
General updating of the D0JetInfo object.  Many additional classes to get at
heavy-flavor relevant information.  This class needs to be linked to the JES
package jetcorr.



d0root_tmbtree/src/TMBReadEvent.cpp
Removed much of the Monte Carlo information access methods.  Modified the
readJet class so as to include the jet energy scale information in the D0Jet
object.



d0root_analysis/algorithms/MCUtilities.cpp &
d0root_analysis/algorithms/MCUtilities.h
Extensive addition of Monte Carlo information access.  It has only been
tested with Pythia data.  The "GetMCLOPartons" is intended to find the two
leading-order partons in the event, but is of limited utility (for instance
it won't find the top quarks in a top event).  What it really does is find
the highest Pt parton and then the second-highest parton more than (pi -
0.7) radians away in phi.  In high Pt events, it is accurate 98.5%+ of the
time.



d0root_btag/algorithms/D0JetInfoMaker.cpp &
d0root_btag/algorithms/D0JetInfoMaker.h
A new method, originally stuffed in TMBReadEvent.cpp.  It builds D0JetInfo
objects...highly-useful constructs which are designed for heavy-flavor
identification.



d0root_btag/analysis/DatabDiJet.cpp & d0root_btag/analysis/DatabDiJet.h
An updated version of the analysis aimed at finding two b-jets with a large
dijet mass.  Has examples for implementing the D0JetInfo object.



d0root_btag/runDatabDiJet.C
Updated method for running d0root_btag/analysis/DatabDiJet.cpp.

Instructions (TMBTree)

In order to run the script, you first need to create a new release area:

//Create release area
//----------------------------------

kinit

newrel -t p14.05.02 mydir
cd mydir
d0setwa
source Maked0root_v9.2.csh

Run analysis code

from mydir directory:
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, X state, and B->J/Psi K+ vertices, do:

    b->Process_diMuons("myOutputFileName", muon_pt, PVbeamConstraint);

• "myOutputFileName" is the name of the output root tree.
• muon_pt is the minimum global muon pT in GeV/c, by default 1.5 GeV/c.
• PVbeamConstraint is set to 0 (false) by default.
• All Loose muons are considered

In order to open the ROOT-tuple and plot the 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")

Please send questions/comments/improvements/ or report problems to the

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