Difference: WJetsAnalysis (1 vs. 10)

Revision 102008-04-15 - ThiagoTomei

Line: 1 to 1
 
META TOPICPARENT name="ThiagoTomei"

W + Jets Analysis

Added:
>
>

This page is obsolete

 

  • Download the tar.gz file that contains the relevant files, and unpack it somewhere. It automatically creates the analysis_SPRACE directory. You can also download it from the table at the botton of this page.

Revision 92007-11-17 - ThiagoTomei

Line: 1 to 1
 
META TOPICPARENT name="ThiagoTomei"

W + Jets Analysis

Line: 24 to 24
 
  • Issue the scramv1 b -r command to compile the EDAnalyzer - it should compile fine. If it does not, you probably misplaced the BuildFile. Correct the mistake and issue the command again. The -r option tells the scramv1 b command to reread all files - if the BuildFile has not changed, it is usually safe to skip that option.
Changed:
<
<
  • The files alpgenw0j_official.root, alpgenw1j_official.root, etc. are, in fact, symbolic links to files which contain a fraction of the events produced by the ALPGEN matrix-element generator with those parton multiplicities (w+1 parton, w+2 partons, etc.). Those events are subject to parton showering and hadronization by PYTHIA, full event simulation by GEANT4, digitization and reconstruction. In this tutorial, we are going to work with the very first link in that chain - the partons produced after the hard interaction. See to where those links are pointing, an make corresponding links (same names!) in the VnjetAnalyzer directory.
>
>
  • The files alpgenw0j_official.root, alpgenw1j_official.root, etc. are, in fact, symbolic links to files which contain a fraction of the events produced by the ALPGEN matrix-element generator with those parton multiplicities (w+1 parton, w+2 partons, etc.). Those events are subject to parton showering and hadronization by PYTHIA, full event simulation by GEANT4, digitization and reconstruction. In this tutorial, we are going to work with the very first link in that chain - the partons produced after the hard interaction. See to where those links are pointing, and make corresponding links (same names!) in the VnjetAnalyzer directory.
 
  • Copy the Configuration Files w0.cfg, w1.cfg to the VnjetAnalyzer directory. These Configuration Files accomplish the following tasks: scan through each Event in the source, select all partons, create parton-level jets ("clusters") with a given cone radius (default is 0.5), cut on the pt of the jets (default is 20 GeV), and produce a series of histograms. Let's focus our attention in two particular histograms: "totalJets", with the number of jets per Event, and "pt_tJets" with the cumulative pt distribution of jets for all Events. Each .cfg is linked to one parton multiplicity, and produces a ROOT file named wnj_ic_pt20_R05.root, with n the same as in the .cfg file.

Revision 82007-11-16 - ThiagoTomei

Line: 1 to 1
 
META TOPICPARENT name="ThiagoTomei"

W + Jets Analysis

Changed:
<
<
  • Download the tar.gz file that contains the relevant files, and unpack it somewhere. It automatically creates the analysis_SPRACE directory.
>
>
  • Download the tar.gz file that contains the relevant files, and unpack it somewhere. It automatically creates the analysis_SPRACE directory. You can also download it from the table at the botton of this page.
 
  • Create an EDAnalyzer called VnjetAnalyzer (the name doesn't really matter, it's just to keep source file compatibility). From the $CMSSW_BASE dir (the CMSSW_1_6_0 dir in this case), issue the following commands:
Line: 20 to 20
 Fig.1
Changed:
<
<
  • Copy the EDAnalyzer (in our case, the VnjetAnalyzer.cc source file) from analysis_SPRACE to the src directory - overwriting the one you just created. Study the structure of the file, and how it uses the Analysis Tools. For more information, check the CMS Workbook in Analysis Tools. Also, copy the BuildFile to the (deeper) VnjetAnalyzer directory.
>
>
  • Copy the EDAnalyzer (in our case, the VnjetAnalyzer.cc source file) from analysis_SPRACE to the src directory - overwriting the one you just created. Study the structure of the file, and how it uses the Analysis Tools, especially the Candidate Model. For more information, check the CMS Workbook in Analysis Tools. Also, copy the BuildFile to the (deeper) VnjetAnalyzer directory. (When we refer to the VnjetAnalyzer directory, it is always the deeper one.)
 
Changed:
<
<
  • Issue the scramv1 b -r command to compile the EDAnalyzer - it should compile fine. If it does not, you probably misplaced the BuildFile. Correct the mistake and issue the command again. The -r option tells the scramv1 b command to reread all files - if the =BuildFile=s have not changed, it is usually safe to skip that option.
>
>
  • Issue the scramv1 b -r command to compile the EDAnalyzer - it should compile fine. If it does not, you probably misplaced the BuildFile. Correct the mistake and issue the command again. The -r option tells the scramv1 b command to reread all files - if the BuildFile has not changed, it is usually safe to skip that option.
 
Changed:
<
<
  • Copy the Configuration Fragments w0.cff, w1.cff, ..., to the $CMSSW_BASE/share directory. These Configuration Fragments contain the location of the sources (ROOT files) for our analysis. The sources contain w + jets Events. The number following the letter w is the number of hard partons that were simulated at matrix-element level. After that, the final state is subject to parton showering and hadronization. These files are NOT used at the moment, but they may be used in the future if the samples are stored in the SPRACE cluster at some point in the future.
>
>
  • The files alpgenw0j_official.root, alpgenw1j_official.root, etc. are, in fact, symbolic links to files which contain a fraction of the events produced by the ALPGEN matrix-element generator with those parton multiplicities (w+1 parton, w+2 partons, etc.). Those events are subject to parton showering and hadronization by PYTHIA, full event simulation by GEANT4, digitization and reconstruction. In this tutorial, we are going to work with the very first link in that chain - the partons produced after the hard interaction. See to where those links are pointing, an make corresponding links (same names!) in the VnjetAnalyzer directory.
 
Changed:
<
<
  • Copy the Configuration Files w0.cfg, w1.cfg to the VnjetAnalyzer directory. These Configuration Files accomplish the following tasks: scan through each Event in the source, select all partons, create parton-level jets ("clusters") with a given cone radius (default is 0.5), cut on the pt of the jets (default is 20 GeV), and produce a series of histograms. Let's focus our attention in two particular histograms: "totalJets", with the number of jets per Event, and "pt_tJets" with the cumulative pt distribution of jets for all Events. Each .cfg is linked to one of the .cff, and produces a ROOT file named wnj_ic_pt20_R05.root, with n the same as in the .cfg and the .cff.
>
>
  • Copy the Configuration Files w0.cfg, w1.cfg to the VnjetAnalyzer directory. These Configuration Files accomplish the following tasks: scan through each Event in the source, select all partons, create parton-level jets ("clusters") with a given cone radius (default is 0.5), cut on the pt of the jets (default is 20 GeV), and produce a series of histograms. Let's focus our attention in two particular histograms: "totalJets", with the number of jets per Event, and "pt_tJets" with the cumulative pt distribution of jets for all Events. Each .cfg is linked to one parton multiplicity, and produces a ROOT file named wnj_ic_pt20_R05.root, with n the same as in the .cfg file.
 
  • Copy this ROOT macro: group.C to the main directory. What this macro does is to group all the ROOT files produced by the .cfg files in a single ROOT file. It also sums the histograms for number of jets per Event and cumulative pt distribution in both exclusive and inclusive ways. For instance, in the "nexclusive" histogram which is created, each bin corresponds to the number of Events that have EXACTLY that number of jets. (There is also a luminosity scale factor involved, so that for a given .cfg file the "totalJets" histogram corresponds to 100/pb). The "ninclusive" histogram works in a similar fashion, except that each bin corresponds to the number of Events that have AT LEAST that number of jets.
Changed:
<
<
  • Run all the Configuration Files: cmsRun w0.cfg, ... This will produce the wnj_ic_pt20_R05.root files.
>
>
  • Run all the Configuration Files: cmsRun w0.cfg, etc. This will produce the wnj_ic_pt20_R05.root files.
 
  • Run the ROOT macro: root -l -q group.C. This will produce the "allw_ic_pt20_R05.root" file.
Changed:
<
<
  • Plot the resulting file with ROOT: root -l allw_ic_pt20_R05.root, and select the "nexclusive" histogram. Plot it in log scale to see that the log of number of events with n jets is a linear function of n. That is because the cross-section for n jets scales as a^n, where a is the strong coupling constant, ("alpha_strong"). If one now fits a linear function to that histogram, the slope should be ln a. It works similarly for the "ninclusive" histogram.
>
>
  • Open the resulting file with ROOT: root -l allw_ic_pt20_R05.root, and select the "nexclusive" histogram. Plot it in log scale to see that the log of number of events with n jets is a linear function of n. That is because the cross-section for n jets scales as a^n, where a is the strong coupling constant, ("alpha_strong"). If one now fits a linear function to that histogram, the slope should be ln a. It works similarly for the "ninclusive" histogram.
  -- ThiagoTomei - 16 Nov 2007
Added:
>
>
 
Changed:
<
<
META FILEATTACHMENT attachment="hyerarchy.png" attr="" comment="" date="1195149445" name="hyerarchy.png" path="hyerarchy.png" size="4696" stream="hyerarchy.png" user="Main.ThiagoTomei" version="2"
>
>
META FILEATTACHMENT attachment="analysis_SPRACE.tar.gz" attr="" comment="Archive containing the files for the tutorial." date="1195221186" name="analysis_SPRACE.tar.gz" path="analysis_SPRACE.tar.gz" size="8599" stream="analysis_SPRACE.tar.gz" user="Main.ThiagoTomei" version="1"

Revision 72007-11-16 - ThiagoTomei

Line: 1 to 1
 
META TOPICPARENT name="ThiagoTomei"

W + Jets Analysis

Line: 14 to 14
 $ mkedanlzr VnjetAnalyzer
Changed:
<
<
This creates the following directory hierarchy: (put a picture here).
>
>
This creates the following directory hierarchy:
 
Changed:
<
<
  • Copy the EDAnalyzer (in our case, the VnjetAnalyzer.cc source file)from analysis_SPRACE to the src directory - overwriting the one you just created. Study the structure of the file, and how it uses the Analysis Tools. For more information, check CMS Workbook in Analysis Tools. Also, copy the BuildFile to the (deeper) VnjetAnalyzer directory.
>
>
Fig.1
 
Changed:
<
<
  • Issue the scramv1 b command to compile the EDAnalyzer - it should compile fine. If it does not, you probably misplaced the BuildFile. Correct the mistake and issue the command again.
>
>
  • Copy the EDAnalyzer (in our case, the VnjetAnalyzer.cc source file) from analysis_SPRACE to the src directory - overwriting the one you just created. Study the structure of the file, and how it uses the Analysis Tools. For more information, check the CMS Workbook in Analysis Tools. Also, copy the BuildFile to the (deeper) VnjetAnalyzer directory.
 
Changed:
<
<
  • Copy the Configuration Fragments w0.cff, w1.cff, ..., to the $CMSSW_BASE/share directory. These Configuration Fragments contain the location of the sources (ROOT files) for our analysis. The sources contain w + jets Events. The number following the letter w is the number of hard partons that were simulated at matrix-element level. After that, the final state is subject to parton showering and hadronization. These files are NOT used at the moment, but they may be used in the future if the samples are stored in the SPRACE cluster at some point in the future.
>
>
  • Issue the scramv1 b -r command to compile the EDAnalyzer - it should compile fine. If it does not, you probably misplaced the BuildFile. Correct the mistake and issue the command again. The -r option tells the scramv1 b command to reread all files - if the =BuildFile=s have not changed, it is usually safe to skip that option.
 
Changed:
<
<
  • Copy the Configuration Files w0.cfg, w1.cfg to the VnjetAnalyzer directory. These Configuration Files accomplish the following tasks: scan through each Event in the source, select all partons, create parton-level jets ("clusters") with a given cone radius (default is 0.5), cut on the pt of the jets (default is 20 GeV), and produce 2 histograms: "totalJets", with the number of jets per Event, and "pt_tJets" with the cumulative pt distribution of jets for all Events. Each .cfg is linked to one of the .cff, and produces a ROOT file named wnj_ic_pt20_R05.root, with n the same as in the .cfg and the .cff.
>
>
  • Copy the Configuration Fragments w0.cff, w1.cff, ..., to the $CMSSW_BASE/share directory. These Configuration Fragments contain the location of the sources (ROOT files) for our analysis. The sources contain w + jets Events. The number following the letter w is the number of hard partons that were simulated at matrix-element level. After that, the final state is subject to parton showering and hadronization. These files are NOT used at the moment, but they may be used in the future if the samples are stored in the SPRACE cluster at some point in the future.
 
Changed:
<
<
  • Copy this ROOT macro: agrupar_pt20_R05.C to the main directory. What this macro does is to group all the ROOT files produced by the .cfg files in a single ROOT file. It also sums the histograms for number of jets per Event and cumulative pt distribution in an EXCLUSIVE way. For instance, in the "nexclusive" histogram which is created, each bin corresponds to the number of Events that have EXACTLY that number of jets. (There is also a luminosity scale factor involved, so that for a given .cfg file the "totalJets" histogram corresponds to 100/pb).
>
>
  • Copy the Configuration Files w0.cfg, w1.cfg to the VnjetAnalyzer directory. These Configuration Files accomplish the following tasks: scan through each Event in the source, select all partons, create parton-level jets ("clusters") with a given cone radius (default is 0.5), cut on the pt of the jets (default is 20 GeV), and produce a series of histograms. Let's focus our attention in two particular histograms: "totalJets", with the number of jets per Event, and "pt_tJets" with the cumulative pt distribution of jets for all Events. Each .cfg is linked to one of the .cff, and produces a ROOT file named wnj_ic_pt20_R05.root, with n the same as in the .cfg and the .cff.

  • Copy this ROOT macro: group.C to the main directory. What this macro does is to group all the ROOT files produced by the .cfg files in a single ROOT file. It also sums the histograms for number of jets per Event and cumulative pt distribution in both exclusive and inclusive ways. For instance, in the "nexclusive" histogram which is created, each bin corresponds to the number of Events that have EXACTLY that number of jets. (There is also a luminosity scale factor involved, so that for a given .cfg file the "totalJets" histogram corresponds to 100/pb). The "ninclusive" histogram works in a similar fashion, except that each bin corresponds to the number of Events that have AT LEAST that number of jets.
 
  • Run all the Configuration Files: cmsRun w0.cfg, ... This will produce the wnj_ic_pt20_R05.root files.
Changed:
<
<
  • Run the ROOT macro: root -l -q agrupar_pt20_R05.C. This will produce the "allw_ic_pt20_R05.root" file.
>
>
  • Run the ROOT macro: root -l -q group.C. This will produce the "allw_ic_pt20_R05.root" file.
 
Changed:
<
<
  • Plot the resulting file with ROOT: root -l allw_ic_pt20_R05.root, and select the "nexclusive" histogram. Plot it in log scale to see that the log of number of events with n jets is a linear function of n. That is because the cross-section for n jets scales as a^n, where a is the strong coupling constant, ("alpha_strong"). If one now fits a linear function to that histogram, the slope should be ln a.
>
>
  • Plot the resulting file with ROOT: root -l allw_ic_pt20_R05.root, and select the "nexclusive" histogram. Plot it in log scale to see that the log of number of events with n jets is a linear function of n. That is because the cross-section for n jets scales as a^n, where a is the strong coupling constant, ("alpha_strong"). If one now fits a linear function to that histogram, the slope should be ln a. It works similarly for the "ninclusive" histogram.
 
Changed:
<
<
-- ThiagoTomei - 06 Nov 2007
>
>
-- ThiagoTomei - 16 Nov 2007
 
META FILEATTACHMENT attachment="hyerarchy.png" attr="" comment="" date="1195149445" name="hyerarchy.png" path="hyerarchy.png" size="4696" stream="hyerarchy.png" user="Main.ThiagoTomei" version="2"

Revision 62007-11-15 - ThiagoTomei

Line: 1 to 1
 
META TOPICPARENT name="ThiagoTomei"

W + Jets Analysis

Line: 16 to 16
  This creates the following directory hierarchy: (put a picture here).
Changed:
<
<
  • Copy the EDAnalyzer from analysis_SPRACE to the src directory - overwriting the one you just created. Study the structure of the file, and how it uses the Analysis Tools. For more information, check CMS Workbook in Analysis Tools
>
>
  • Copy the EDAnalyzer (in our case, the VnjetAnalyzer.cc source file)from analysis_SPRACE to the src directory - overwriting the one you just created. Study the structure of the file, and how it uses the Analysis Tools. For more information, check CMS Workbook in Analysis Tools. Also, copy the BuildFile to the (deeper) VnjetAnalyzer directory.
 
Changed:
<
<
  • Issue the scramv1 b command to compile the EDAnalyzer - it should compile fine.
>
>
  • Issue the scramv1 b command to compile the EDAnalyzer - it should compile fine. If it does not, you probably misplaced the BuildFile. Correct the mistake and issue the command again.
 
Changed:
<
<
  • Copy the Configuration Fragments w0.cff, w1.cff, ..., to the $CMSSW_BASE/share directory. These Configuration Fragments contain the location of the sources (ROOT files) for our analysis. The sources contain w + jets Events. The number following the letter w is the number of hard partons that were simulated at matrix-element level. After that, the final state is subject to parton showering and hadronization.
>
>
  • Copy the Configuration Fragments w0.cff, w1.cff, ..., to the $CMSSW_BASE/share directory. These Configuration Fragments contain the location of the sources (ROOT files) for our analysis. The sources contain w + jets Events. The number following the letter w is the number of hard partons that were simulated at matrix-element level. After that, the final state is subject to parton showering and hadronization. These files are NOT used at the moment, but they may be used in the future if the samples are stored in the SPRACE cluster at some point in the future.
 
  • Copy the Configuration Files w0.cfg, w1.cfg to the VnjetAnalyzer directory. These Configuration Files accomplish the following tasks: scan through each Event in the source, select all partons, create parton-level jets ("clusters") with a given cone radius (default is 0.5), cut on the pt of the jets (default is 20 GeV), and produce 2 histograms: "totalJets", with the number of jets per Event, and "pt_tJets" with the cumulative pt distribution of jets for all Events. Each .cfg is linked to one of the .cff, and produces a ROOT file named wnj_ic_pt20_R05.root, with n the same as in the .cfg and the .cff.
Line: 33 to 33
 
  • Plot the resulting file with ROOT: root -l allw_ic_pt20_R05.root, and select the "nexclusive" histogram. Plot it in log scale to see that the log of number of events with n jets is a linear function of n. That is because the cross-section for n jets scales as a^n, where a is the strong coupling constant, ("alpha_strong"). If one now fits a linear function to that histogram, the slope should be ln a.

-- ThiagoTomei - 06 Nov 2007 \ No newline at end of file

Added:
>
>
META FILEATTACHMENT attachment="hyerarchy.png" attr="" comment="" date="1195149445" name="hyerarchy.png" path="hyerarchy.png" size="4696" stream="hyerarchy.png" user="Main.ThiagoTomei" version="2"

Revision 52007-11-08 - ThiagoTomei

Line: 1 to 1
 
META TOPICPARENT name="ThiagoTomei"

W + Jets Analysis

Line: 16 to 16
  This creates the following directory hierarchy: (put a picture here).
Changed:
<
<
>
>
  • Copy the EDAnalyzer from analysis_SPRACE to the src directory - overwriting the one you just created. Study the structure of the file, and how it uses the Analysis Tools. For more information, check CMS Workbook in Analysis Tools
 
  • Issue the scramv1 b command to compile the EDAnalyzer - it should compile fine.

Revision 42007-11-06 - ThiagoTomei

Line: 1 to 1
 
META TOPICPARENT name="ThiagoTomei"

W + Jets Analysis

Line: 6 to 6
 
  • Download the tar.gz file that contains the relevant files, and unpack it somewhere. It automatically creates the analysis_SPRACE directory.
Changed:
<
<
  • Create an EDAnalyzer called CandJetMatcher (the name doesn't really matter, it's just to keep source file compatibility). From the $CMSSW_BASE dir (the CMSSW_1_6_0 dir in this case), issue the following commands:
>
>
  • Create an EDAnalyzer called VnjetAnalyzer (the name doesn't really matter, it's just to keep source file compatibility). From the $CMSSW_BASE dir (the CMSSW_1_6_0 dir in this case), issue the following commands:
 
Changed:
<
<
$ mkdir CandJetMatcher $ cd CandJetMatcher $ mkedanlzr CandJetMatcher
>
>
$ mkdir VnjetAnalyzer $ cd VnjetAnalyzer $ mkedanlzr VnjetAnalyzer
 
Changed:
<
<
This creates the following directory hierarchy: (put a picture here). From now on, we will always work with the (deeper) CandJetMatcher directory as our main directory, except when told otherwise.
>
>
This creates the following directory hierarchy: (put a picture here).
 
Changed:
<
<
  • Copy the EDAnalyzer from analysis_SPRACE to the src directory - overwriting the one you just created.
>
>
 
  • Issue the scramv1 b command to compile the EDAnalyzer - it should compile fine.
Changed:
<
<
  • Copy the Configuration Fragments w0.cff, w1.cff, ..., to the $CMSSW_BASE/share directory. These Configuration Fragments contain the location of the sources (ROOT files) for our analysis. The sources contain w + jets Events. The number following the letter w is the number of hard partons that were simulated at matrix-element level. After that, the final state is subject to parton showering, but NOT to hadronization - therefore, the Events have partons as "final-state particles".
>
>
  • Copy the Configuration Fragments w0.cff, w1.cff, ..., to the $CMSSW_BASE/share directory. These Configuration Fragments contain the location of the sources (ROOT files) for our analysis. The sources contain w + jets Events. The number following the letter w is the number of hard partons that were simulated at matrix-element level. After that, the final state is subject to parton showering and hadronization.
 
Changed:
<
<
  • Copy the Configuration Files w0.cfg, w1.cfg to the main directory. These Configuration Files accomplish the following tasks: scan through each Event in the source, select all partons, create parton-level jets ("clusters") with a given cone radius (default is 0.5), cut on the pt of the jets (default is 20 GeV), and produce 2 histograms: "totalJets", with the number of jets per Event, and "pt_tJets" with the cumulative pt distribution of jets for all Events. Each .cfg is linked to one of the .cff, and produces a ROOT file named wnj_ic_pt20_R05.root, with n the same as in the .cfg and the .cff.
>
>
  • Copy the Configuration Files w0.cfg, w1.cfg to the VnjetAnalyzer directory. These Configuration Files accomplish the following tasks: scan through each Event in the source, select all partons, create parton-level jets ("clusters") with a given cone radius (default is 0.5), cut on the pt of the jets (default is 20 GeV), and produce 2 histograms: "totalJets", with the number of jets per Event, and "pt_tJets" with the cumulative pt distribution of jets for all Events. Each .cfg is linked to one of the .cff, and produces a ROOT file named wnj_ic_pt20_R05.root, with n the same as in the .cfg and the .cff.
 
  • Copy this ROOT macro: agrupar_pt20_R05.C to the main directory. What this macro does is to group all the ROOT files produced by the .cfg files in a single ROOT file. It also sums the histograms for number of jets per Event and cumulative pt distribution in an EXCLUSIVE way. For instance, in the "nexclusive" histogram which is created, each bin corresponds to the number of Events that have EXACTLY that number of jets. (There is also a luminosity scale factor involved, so that for a given .cfg file the "totalJets" histogram corresponds to 100/pb).
Changed:
<
<
  • Run all the Configuration Files: cmsRun w0.cfg , ... . This step can be quite time-consuming, because most of the source files reside either at CERN and/or FNAL, and they must be locally cached before analysis can begin. This will produce the wnj_ic_pt20_R05.root files.
>
>
  • Run all the Configuration Files: cmsRun w0.cfg, ... This will produce the wnj_ic_pt20_R05.root files.
 
  • Run the ROOT macro: root -l -q agrupar_pt20_R05.C. This will produce the "allw_ic_pt20_R05.root" file.

  • Plot the resulting file with ROOT: root -l allw_ic_pt20_R05.root, and select the "nexclusive" histogram. Plot it in log scale to see that the log of number of events with n jets is a linear function of n. That is because the cross-section for n jets scales as a^n, where a is the strong coupling constant, ("alpha_strong"). If one now fits a linear function to that histogram, the slope should be ln a.
Changed:
<
<

ThiagoTomei - 09 Oct 2007
>
>
-- ThiagoTomei - 06 Nov 2007
 \ No newline at end of file

Revision 32007-10-09 - ThiagoTomei

Line: 1 to 1
 
META TOPICPARENT name="ThiagoTomei"

W + Jets Analysis

Changed:
<
<
>
>
 
Changed:
<
<
  • Create an EDAnalyzer called CandJetMatcher (the name doesn't really matter
>
>
  • Download the tar.gz file that contains the relevant files, and unpack it somewhere. It automatically creates the analysis_SPRACE directory.
 
Changed:
<
<
  • Copy the EDANalyzer to the src directory
  • scramv1 b
  • Copy the Configuration Fragments w0.cff, w1.cff, ..., to the share directory
  • Copy the Configuration Files w0.cfg, w1.cfg to the main directory
  • Copy this ROOT macro: agrupar_pt30_R05.C to the main directory
  • Run all the Configuration Files: cmsRun w0.cfg , ...
  • Run the ROOT macro: root -lq agrupar_pt30_R05.C
  • Plot the resulting file with ROOT: root -l allw_ic_pt30_R05.root, and select the wsum histogram. Plot it in log scale to see that the log of number of events with N jets is a linear function of N.
>
>
  • Create an EDAnalyzer called CandJetMatcher (the name doesn't really matter, it's just to keep source file compatibility). From the $CMSSW_BASE dir (the CMSSW_1_6_0 dir in this case), issue the following commands:
 
Added:
>
>
$ mkdir CandJetMatcher
$ cd CandJetMatcher
$ mkedanlzr CandJetMatcher
 
Added:
>
>
This creates the following directory hierarchy: (put a picture here). From now on, we will always work with the (deeper) CandJetMatcher directory as our main directory, except when told otherwise.
 
Changed:
<
<
-- ThiagoTomei - 08 Oct 2007
>
>
  • Copy the EDAnalyzer from analysis_SPRACE to the src directory - overwriting the one you just created.

  • Issue the scramv1 b command to compile the EDAnalyzer - it should compile fine.

  • Copy the Configuration Fragments w0.cff, w1.cff, ..., to the $CMSSW_BASE/share directory. These Configuration Fragments contain the location of the sources (ROOT files) for our analysis. The sources contain w + jets Events. The number following the letter w is the number of hard partons that were simulated at matrix-element level. After that, the final state is subject to parton showering, but NOT to hadronization - therefore, the Events have partons as "final-state particles".

  • Copy the Configuration Files w0.cfg, w1.cfg to the main directory. These Configuration Files accomplish the following tasks: scan through each Event in the source, select all partons, create parton-level jets ("clusters") with a given cone radius (default is 0.5), cut on the pt of the jets (default is 20 GeV), and produce 2 histograms: "totalJets", with the number of jets per Event, and "pt_tJets" with the cumulative pt distribution of jets for all Events. Each .cfg is linked to one of the .cff, and produces a ROOT file named wnj_ic_pt20_R05.root, with n the same as in the .cfg and the .cff.

  • Copy this ROOT macro: agrupar_pt20_R05.C to the main directory. What this macro does is to group all the ROOT files produced by the .cfg files in a single ROOT file. It also sums the histograms for number of jets per Event and cumulative pt distribution in an EXCLUSIVE way. For instance, in the "nexclusive" histogram which is created, each bin corresponds to the number of Events that have EXACTLY that number of jets. (There is also a luminosity scale factor involved, so that for a given .cfg file the "totalJets" histogram corresponds to 100/pb).

  • Run all the Configuration Files: cmsRun w0.cfg , ... . This step can be quite time-consuming, because most of the source files reside either at CERN and/or FNAL, and they must be locally cached before analysis can begin. This will produce the wnj_ic_pt20_R05.root files.

  • Run the ROOT macro: root -l -q agrupar_pt20_R05.C. This will produce the "allw_ic_pt20_R05.root" file.

  • Plot the resulting file with ROOT: root -l allw_ic_pt20_R05.root, and select the "nexclusive" histogram. Plot it in log scale to see that the log of number of events with n jets is a linear function of n. That is because the cross-section for n jets scales as a^n, where a is the strong coupling constant, ("alpha_strong"). If one now fits a linear function to that histogram, the slope should be ln a.


ThiagoTomei - 09 Oct 2007

Revision 22007-10-09 - ThiagoTomei

Line: 1 to 1
 
META TOPICPARENT name="ThiagoTomei"

W + Jets Analysis

Changed:
<
<
  • First, set up CMSSW 160 as described in CMSSWSPRACE
  • Create an EDAnalyzer: (describe how to do it)
>
>

  • Create an EDAnalyzer called CandJetMatcher (the name doesn't really matter
 
  • Copy the EDANalyzer to the src directory
  • scramv1 b
  • Copy the Configuration Fragments w0.cff, w1.cff, ..., to the share directory

Revision 12007-10-08 - ThiagoTomei

Line: 1 to 1
Added:
>
>
META TOPICPARENT name="ThiagoTomei"

W + Jets Analysis

  • First, set up CMSSW 160 as described in CMSSWSPRACE
  • Create an EDAnalyzer: (describe how to do it)
  • Copy the EDANalyzer to the src directory
  • scramv1 b
  • Copy the Configuration Fragments w0.cff, w1.cff, ..., to the share directory
  • Copy the Configuration Files w0.cfg, w1.cfg to the main directory
  • Copy this ROOT macro: agrupar_pt30_R05.C to the main directory
  • Run all the Configuration Files: cmsRun w0.cfg , ...
  • Run the ROOT macro: root -lq agrupar_pt30_R05.C
  • Plot the resulting file with ROOT: root -l allw_ic_pt30_R05.root, and select the wsum histogram. Plot it in log scale to see that the log of number of events with N jets is a linear function of N.

-- ThiagoTomei - 08 Oct 2007

 
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