Difference: JetFlavourTagging (3 vs. 4)

Revision 42013-07-01 - DanProtopopescu

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

ZZ Fusion Analysis

Added:
>
>
This is a detailed record on how the Marlin framework and adjacent packages are used for our analysis of the feasibility of the ZZ fusion channel with CLIC ILD at 1.4 TeV.
 
Added:
>
>
BRTotalUncertBands.png
 
Changed:
<
<

Neural Network training

>
>

Jet Finder and Flavour Tagging

 
Changed:
<
<		We use the flavour tagging package LCFIVertex. This package consists of a topological vertex finder ZVTOP, which reconstructs secondary interactions, and a multivariate classifier which combines several jet-related variables to tag bottom, charm, and light quark jets.
>
>		We use the LCFI flavour tagging package. This package consists of a topological vertex finder ZVTOP, which reconstructs secondary interactions, and a multivariate classifier which combines several jet-related variables to tag bottom, charm, and light quark jets (see diagram).
 
Changed:
<
<		Our steering file will contain the following LCFI component processors and a neural net trainer:
>
>		Our steering file will contain the jet finder, flavour tagging and LCFI processors, and we will write new slcio files containing the added collections:
 
  <group name="JetFinders"/>
  <group name="MyTrueAngularJetFlavourProcessorCollection"/>
Line: 18 to 25
 
Changed:
<
<
>
>
 
Changed:
<
<		These processors have the following functions:
>
>		The JetFinder processor reconstructs 4 jets events from the input collection (LooseSelectedPandoraPFANewPFOs was used). For the reconstructed 4 jets, TrueAngularJetFlavourProcessor does 'truth tagging', i.e. determines the MC jet flavour (b-jet or c-jet).

The LCFI processors have the following functions:

 
  • IPRPCut - selects Reconstructed Particles based on track parameters, number of hits etc.
Changed:
<
<
  • PerEventIPFitter - finds the event Impact Parameter
>
>
  • PerEventIPFitter - finds the event Interaction Point
 
  • ZVRESRP - vertex finder for reconstructed particles
  • ZVTOP_ZVRES - topological vertex finder
  • FTRPCut: - flavour tagging reconstructed particle cuts
  • FlavourTagInputs - from vertices and tracks calculates discriminating variables for the neural net
Changed:
<
<
  • NeuralNetTrainer - trains the networks
>
>		 The LCIOOutput processor creates new slcio files containing the new collections added by the above processors. We found that the most time-consuming processor is ZVTOP_ZVRES with more than 10 s/event.

Neural Network Training

The slcio files created at the previous step contain the collections Durham_4Jets, FlavourTagInputs and TrueJetFlavour_4Jets, which we will use now to train our neural nets. We use the NeuralNetTrainer code included in the LCFI package. Separate nets were trained for 1, 2, or 3+ vertices to identify b-jets, c-jets, and c-jets with b background. Our steering file contains only: 

  <processor name="MyNeuralNetTrainer" type="NeuralNetTrainer"/>
  The neural nets are saved as XML files in nnets/ and will be used for flavour tagging (next step). No slcio output is written at this time.
Added:
>
>

Purity and Efficiency Studies

To determine the optimal cut for our b-tagging, a purity vs. efficiency study was performed.

 

Flavour Tagging

Changed:
<
<
  • TrueJetFlavour - determines MC flavour of reconstructed jets
>
>		Now are ready to employ the FlavourTag processor, which will do flavour tagging using the neural nets trained in the previous step. Our steering file contains the following processors:
 
Changed:
<
<		A new file containing with these collections added is saved to be used in our analysis.
>
>
  <processor name="MyFlavourTag"/>
  <processor name="ZZfusion"/>
 
Changed:
<
<

Acceptance Studies

>
>		The ZZfusion processor is used in our analysis.
 
Changed:
<
<

Four Jet Events

>
>

Acceptance Studies

 
Deleted:
<
<

Purity and Efficiency Studies

 

Electrons from Hard Bremsstrahlung

Luminosity and Event Weights

Deleted:
<
<		-- DanProtopopescu - 2013-06-28
 \ No newline at end of file
Added:
>
>

META FILEATTACHMENT attachment="BRTotalUncertBands_lm.png" attr="" comment="Higgs branching ratios (from A. Denner et al., EPJ C71, p.1753)" date="1372689661" name="BRTotalUncertBands_lm.png" path="BRTotalUncertBands.png" size="114345" stream="BRTotalUncertBands.png" tmpFilename="/usr/tmp/CGItemp36847" user="DanProtopopescu" version="2"
META FILEATTACHMENT attachment="Timing-ScreenShot.png" attr="" comment="Screen shot: time used by Marlin processors" date="1372694627" name="Timing-ScreenShot.png" path="Timing-ScreenShot.png" size="72589" stream="Timing-ScreenShot.png" tmpFilename="/usr/tmp/CGItemp32197" user="DanProtopopescu" version="1"
META FILEATTACHMENT attachment="LCFI_Flow_Diagram.pdf" attr="" comment="LCFI processors - flow diagram" date="1372695037" name="LCFI_Flow_Diagram.pdf" path="LCFI Flow Diagram.pdf" size="89775" stream="LCFI Flow Diagram.pdf" tmpFilename="/usr/tmp/CGItemp32291" user="DanProtopopescu" version="1"
META FILEATTACHMENT attachment="Vertexing_Howto.pdf" attr="" comment="Vertexing HowTo (Ben Jeffery)" date="1372697529" name="Vertexing_Howto.pdf" path="Vertexing Howto.pdf" size="761330" stream="Vertexing Howto.pdf" tmpFilename="/usr/tmp/CGItemp32366" user="DanProtopopescu" version="1"
META FILEATTACHMENT attachment="jet_truth_tag-steer.xml" attr="" comment="Steering file 1: jet finder and truth flavour tagging" date="1372699245" name="jet_truth_tag-steer.xml" path="jet_truth_tag-steer.xml" size="84107" stream="jet_truth_tag-steer.xml" tmpFilename="/usr/tmp/CGItemp32410" user="DanProtopopescu" version="1"
View topic | History: r30 < r29 < r28 < r27 | More topic actions...
 
This site is powered by the TWiki collaboration platform Powered by PerlCopyright © 2008-2025 by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Ideas, requests, problems regarding TWiki? Send feedback