MatrixElementMethod

* This TWiki will inform you of what I will have updated, give some examples to use MELTools, and show the performance.

MELTools: An implementation of Matrix Element Method

• Matrix Element Likelihood Tools (MELTools) is a package for RootCore to adapt Matrix Element Method to Stop 1L analysis
• MELTools is being developed with inspiration from Shion Chen's Matrix Element Method code.
  • References to Shion Chen's Matrix Element Method code (maybe updated later)
  • https://indico.cern.ch/event/392779/session/2/contribution/2/attachments/785732/1077062/SUSYEW2-3lepMTG_20150507.pdf
  • https://indico.cern.ch/event/398330/session/2/contribution/4/attachments/798828/1094880/SUSYEW2-3lepMTG_20150604.pdf
  • Code used in SUSY EW analysis can be seen on SVN: https://svnweb.cern.ch/cern/wsvn/atlas-shion/MELProcessor_WZ_lvll/
• An internal note is being prepared
• (28 April 2016 UP!) Note for Matrix Element Likelihood Calculation at stop1L analysis
  • 20160428_NoteForMELCalcStop1L.pdf
  • This explains how I calculate matrix element likelihood with actually used equations for signal likelihood
  • Signal likelihood will be uploaded (soon?)

Recommended Version

• MELTools-00-00-02

Introduction to MELTools

• MELTools is being developed, opened and maintained by Tatsuya Mori
  • You can see and try it: https://svnweb.cern.ch/cern/wsvn/atlas-mori/MEM/MELTools/trunk/
• Brief Explanation for Installation:
  • (1) In your RootCore directory, type svn co svn+ssh://svn.cern.ch/reps/atlas-mori/MEM/MELTools/trunk MELTools
  • (2) Please read MEMTools/doc/HowToUse
• Brief Code Description:
  • I decided to use doxygen. You can see it, for example, by typing firefox MELTools/doc/html/index.html
• You can test Shion Chen's code with some adaptation to RootCore in the following version:
  • svn co https://svnweb.cern.ch/cern/wsvn/atlas-mori/MEM/MELTools/tags/MELTools-00-00-02 MELTools
  • I presented a performance check for stop 1L analysis
    • https://indico.cern.ch/event/492159/contribution/0/attachments/1225959/1794660/20160210_TatsuyaMori_stop1L_informal_MTG.pdf

Development Status

• Currently, MELTools can only calculate tt-->[bw][blv] likelihood, where the w is completely lost, in other words, lepton from the w is lost.

Future Plan

• More information about consuming time
• Signal Likelihood Calculator
• Transfer Functions
• Implement an intelligent integration (importance sampling, sample importance resampling, mcmc, etc.)
• Try GPU
• Validate MELTools with data

References

• Latest presentations
  • https://indico.cern.ch/event/531392/#10-studies-on-tn_diagonal
  • https://indico.cern.ch/event/531390/#9-tn_diagonal-mel
  • https://indico.cern.ch/event/531490/#10-status-on-matrix-element-me

Useful Links

• Will be added!