An analysis demo: search for Higgs boson in the decay H→WW
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README
analyze.py
skim.py
submitel.txt
submitmu.txt

README

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"HiggsSearchDemo" is a collection of few simple Python scripts to 
analyze data from the Large Hadron Collider (CMS experiment) to 
search for the Higgs boson in the decay H->WW.


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git clone https://github.com/kalanand/HiggsSearchDemo



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There are three basic steps to the LHC data analysis (after step 0). 

Step 0: Get familiar with "VPlusJets" package following instructions at 
     https://twiki.cern.ch/twiki/bin/view/CMSPublic/SWGuideEWKVPlusJets
     
     You do not necessarily need it for this demo, but the tree data structure  
     is defined there.

Step 1: Run over the entire data, filter interesting events, and store 
	 their contents in Ntuple format. The goal of this step is to identify 
	 events with two W bosons and store all necessary information needed 
	 for physics analysis. The event should contain an electron or muon, 
	 large missing energy due to an escaped neutrino, and at least two high 
	 energy particle jets. We run this step as a large number of parallel 
	 jobs on Condor batch machines

	 condor_submit submitmu.txt
	 condor_submit submitel.txt

Step 2: Select signal-like events (i.e., "map reduce"). In this step we 
	 perform a further 10^3 reduction in data size and select signal-like 
	 events. We apply tight quality criteria specified in "skim.py" file 
	 and drop information not needed for further analysis.
	 
	 python skim.py

	
Step 3: Perform Higgs search (i.e., "data analytics"). Now we analyze the 
	 remaining events for any hints of Higgs signal. We plot the invariant 
	 mass of the two W bosons. If Higgs boson decays to WW, then we would 
	 expect a mass peak in this distribution corresponding to the Higgs 
	 boson mass. Modify the analyzer script according to your needs and run:

	 python analyze.py

	 The default version of the script in this repository should produce 
	 a plot of the m_WW distribution in data and compare it to the expected   
	 background from simulation. The plot also shows the magnitude of 
	 Higgs signal for a few hypothetical Higgs mass values.  
	 We find that the data is consistent with background-only hypothesis. 
	 Given the expected magnitude of Higgs signal, we can 
	 exclude Higgs boson mass in the range 200-600 GeV with 95% confidence. 
	 This is what we actually did with the early LHC data before eventually 
	 discovering the Higgs boson at mass 125 GeV on July 4, 2012. 
    


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Please see: http://kmishra.net/AnalysisDemo


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Author : Kalanand Mishra
Home Page : https://github.com/kalanand/HiggsSearchDemo
Operating System : OS Independent
Programming Language : Python 
Intended Audience : High Energy Physics students 


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HiggsSearchDemo is a free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 3 of the
License or any later version: <http://www.gnu.org/licenses/>.
This software is distributed WITHOUT ANY WARRANTY.