ATLAS Analysis: Additional Scalar (AS) decay via dark vector bosons to a 4-lepton plus MET final state

H(d) -> 2S -> 4Zd -> 4l + MET

Repository purpose/ aim/ goal

The purpose of this repository is to generate data for decays with a 4l+MET final state, then analyse this data. The repository is divided into two main sections:

• Generation code - produces simulated data
• Analysis code - produces plots and useful information from simulated data

How to run

Generation

Basic Analysis

Brief version:

• Copy analysis/source/ directory to your working directory (assumed to be on lxplus)
• In that working directory, create build/ and run/ directories
• In build/
  • setupATLAS
  • asetup AnalysisBase,24.2.35
  • cmake ../source/
  • make
• In run/
  • source ../build/x86_64-el9-gcc13-opt/setup.sh
  • ATestRun_eljob.py --submission-dir=submitDir
  • Repeat for any more DAOD files (you can edit the inputFilePath in ATestRun_eljob.py)
• On your local PC, in the repository main directory (4lMET_Ana/)
  • scp the hist-reco.root files from the folder generated in the previous step to a folder outside of 4lMET_Ana/
  • root basic-analysis/sum_Nparticles.C
  • root basic-analysis/plot_Stacks.C

Detailed version:

Environments

Generation code

Lxplus

• HTCondor version??
• MadGraph version??
• Pythia version??
• Python 3.9.12
• ROOT Version: 6.28/10

  Analysis Code

  Lxplus:

• ROOT Version: 6.28/10
• Python Version: 3.9.12
• Platform: linuxx8664gcc
• Compiler: g++ (GCC) 13.1.0
• C++ version?? Local PC:
• ROOT Version: 6.28/00
• Python 3.11.3
• C++ version??

General info

Generation code

• Simulated decay data is generated in two steps:
  • Generation programs (e.g. Pythia, MadGraph, HERWIG) simulate decays using quantum mechanics and the Monte Carlo (MC) method.
  • Reconstruction programs repackage the resulting data into .root files
• Decay chains, particles, decay widths, etc. can be customized.
• Resulting data is called 'truth level' data - all information on all particles is known.
• A typical sample fit for analysis:
  • 10,000 decay events
  • 0.5-1 hour to generate
  • 3-5Gb of data

    Analysis code

    Analysis code has 3 sections

• includes/ - commonly used functions written as their own files
  • getHistParams - returns the number of bins and x-axis range of input histogram INCOMPLETE
  • scaleHist - scales a histogram and writes it to a .root file
  • stackHists - loops through iterable, adding histograms to THStack, then draws and saves the THStack plot
  • sumHists - loops through iterable, adding histograms together, then writes the combined histogram to a .root file
  • updateMaxEntries - returns the max of (max bin entries for a given hist : given float)
• basic-analysis/ - takes you from a DAOD file to basic kinematic plots
  • The source/ directory contains code for running through events and saving relevant variables to histograms in a .root file
  • sum_Nparticles.C takes the .root file produced from the previous step and in the cases where there are multiple instances of one particle per event, it combines those histograms into one in a new .root file
  • plot_Stacks.C takes the .root file produced from sum_Nparticles.C and produces quality plots as .pdf or .png files.
• advanced-analyses/ - codes for specific analyses
  • For example scaling based on a variable, looking at variables when boosted into a new reference frame, etc.
  • How to run each analysis is detailed in the README.md file in the advance-analyses/ directory.