Run 2 H->bb twiki

Twiki to document the Run 2 H->bb analysis. Will also cover useful code stuff.

xAODs

The new data format for run 2 is xAOD. It is a root readable AOD.

setupATLAS
asetup here,19.1.X.Y-VAL,rel_3,AtlasDerivation
checkSG.py xAOD.pool.root 

Shower Deconstruction

Shower deconstruction is a jet substructure method that uses fat jets reclustered into small R jets to discriminate between signal and background. It takes these reclustered jets and calculates a how similar to a signal model they are. It runs every possible permutation when assigning each subjet to, in our case, two b jets, underlying event ISR and FSR(have I missed one?) and sums every permutation. It then does the same for background. The ration of these two values is called Χ and is the variable used to cut/train on. REFERENCES!!!!

CERN Run 2 Analysis Framework

https://twiki.cern.ch/twiki/bin/view/AtlasProtected/EventLoop

The VH twiki can be found here

https://twiki.cern.ch/twiki/bin/view/AtlasProtected/CxAODFramework

Local Test Run

setupATLAS
rcSetup Base,2.0.18
rc find_packages
rc compile
hsg5framework myDir

This will automatically make a directory called myDir and inside it you will find a directory called data-outputLabel/ which contains a file with all the trees saved by the analysis framework. There is also another folder called output-outputLabel/ which contains a file with some metadata information stored inside.

Running On The Grid

Making Plots From Your Shiny New Grid Files

To make plots there is an executable called hsg5frameworkReadCxAOD that currently has some hard coded information you will need to edit. If you open FrameworkExe/util/hsg5frameworkReadCxAOD.cxx and edit the variable dataset_dir. This is where the input files should be located. There is also a vector called sample_names which contains the names of the folders for each seperate background. The code will make one file filled with histograms for each of the backgrounds in this vector.

(Note: FrameworkExe/data/framework-read.cfg is the config file. Currently it only sets the number of events and the analysis type(0, 1 or 2 lepton).

An example might make things clearer. Imagine a simple analysis that just has muon data, top and Zbb. The folder structure should be as follows

/my/output/folder/

    /my/output/folder/muon_data
             /my/output/folder/muon_data/data-outputLabel
             /my/output/folder/muon_data/output-outputLabel

    /my/output/folder/top
      ....

    /my/output/folder/Zbb
      .....

This will make output files hist-Zbb.root, hist-muon_data.root, hist-top.root.

To make stacked plots from these files we then do root -b -q 'FrameworkExe/macros/runCxAODPlots.cxx("submitDir")' where submitDir is the directory that contains the hist-*.root files.

-- Paul Mullen - 2014-10-02

Comments