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Example code to produce the di-muon spectrum from a CMS 2010 primary dataset

Geiser, Achim ; Dutta, Irene ; Hirvonsalo, Harri ; Sheeran, Bridget

Cite as: Geiser, Achim; Dutta, Irene; Hirvonsalo, Harri; Sheeran, Bridget; (2016). Example code to produce the di-muon spectrum from a CMS 2010 primary dataset. CERN Open Data Portal. DOI:10.7483/OPENDATA.CMS.TF26.KG2D

Data recorded in 2010 and published in 2016

Software Analysis CMS CERN-LHC

Description

This simple analysis example is set up at Research level, i.e. it requires university-student-level programming experience. Minimal acquaintance with Linux and the ROOT analysis package (https://root.cern.ch/) as well as a basic text editor is needed.

Use with

Use this with 2010 Mu primary datasets or any other 2010 primary datasets containing muons.

/Mu/Run2010B-Apr21ReReco-v1/AOD

System details

Use this code with the CMS Open Data VM environment
CMSSW_4_2_8

CMS VM Image, for 2010 CMS open data

How can you use this?

If you do not have the CERN Virtual Machine for 2010 CMS data installed, follow the instructions in step 1 at How to install a CERN Virtual Machine. Then install and run the Demo (demo analyzer) program following the instructions at How to Test & Validate.

To run the "di-muon spectrum" demo:

  1. Create directory datasets under Demo/DemoAnalyzer.
  2. Download the index files for the /Mu/Run2010B-Apr21ReReco-v1/AOD primary datasets and store them in Demo/DemoAnalyzer/datasets/.
  3. Download the JSON file from CMS Validated Runs and save it to the Demo/DemoAnalyzer/datasets directory.
  4. Replace the three files BuildFile.xml, demoanalyzer_cfg.py, src/DemoAnalyzer.cc with the ones from this record and read the comments in DemoAnalyzer.cc if you want to understand what the program does.
  5. Recompile (scram b) and rerun (cmsRun ...) exactly as shown before in How to Test & Validate.
  6. You should get an output file Mu.root, which contains histograms for 10000 input events (a small subset of the data). These can be looked at using a ROOT Browser (see above, under Description). The most interesting histogram is GM_mass_log. In order to compare it with the invariant-mass spectrum of di-muons in MUO-10-004, it should be viewed with the logy option. Of course with 10000 events the comparison is poor, but the J/ψ (at log10(mass)=0.5), Υ (at log10(mass=0.98)) and Z (at log10(mass)=1.95, one event only) peaks should be visible.
  7. Finally, to run over more or even the full data, edit the relevant parts of the Python file demoanalyzer_cfg.py (see comments therein) and rerun. Add up the output histograms from different (non-overlapping) input index files using ROOT tools.


      

    



                
    

        
            
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