Difference: LowPtVertices (1 vs. 4)

Revision 42006-11-14 - FerencSikler

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Vertices with low pT tracks

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  dijet.png
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Event gallery

EventGalleryDijet
 

Minimum bias

Minimum bias Pythia p+p events at 14 TeV. Generated, simulated and reconstructed with CMSSW_1_2_0_pre1 with special code for low pT reconstruction.

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Event gallery

EventGallery
 

Vertex resolution

Distribution of vertex residuals with the standard setting (PtMin=1GeV/c) and the low pT setting (PtMin=0).

Revision 32006-11-13 - FerencSikler

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Vertices with low pT tracks

Minimum bias Pythia p+p events at 14 TeV. Generated, simulated and reconstructed with CMSSW_1_2_0_pre1 with special code for low pT reconstruction.

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Vertices with low pT tracks

 
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Dijet

Two jet Pythia events (produced with PythiaZ700dijets.cfi). Generated, simulated and reconstructed with CMSSW_1_2_0_pre1 with special code for low pT reconstruction. The distribution of number of found vertices (NVertices) with several NTrkMin settings, keeping ZSeparation=0.05cm and PtMin=0. While with NTrkMin=5 there are a lot of events with multiple vertices, with NTrkMin=10 their frequency is below 1%.

dijet.png

Minimum bias

Minimum bias Pythia p+p events at 14 TeV. Generated, simulated and reconstructed with CMSSW_1_2_0_pre1 with special code for low pT reconstruction.

 

Vertex resolution

Distribution of vertex residuals with the standard setting (PtMin=1GeV/c) and the low pT setting (PtMin=0).
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META FILEATTACHMENT attr="h" autoattached="1" comment="" date="1163358659" name="vertices.png" path="vertices.png" size="6651" user="Main.FerencSikler" version="1"
META FILEATTACHMENT attr="h" autoattached="1" comment="" date="1163358918" name="resolution.png" path="resolution.png" size="4461" user="Main.FerencSikler" version="1"
META FILEATTACHMENT attr="h" autoattached="1" comment="" date="1163358738" name="vertices_b.png" path="vertices_b.png" size="5988" user="Main.FerencSikler" version="1"
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META FILEATTACHMENT attr="h" autoattached="1" comment="" date="1163449055" name="dijet.png" path="dijet.png" size="4218" user="Main.FerencSikler" version="1"
 
META FILEATTACHMENT attr="h" autoattached="1" comment="" date="1163358685" name="vertices_a.png" path="vertices_a.png" size="6711" user="Main.FerencSikler" version="1"
META FILEATTACHMENT attr="h" autoattached="1" comment="" date="1163358646" name="multidep.png" path="multidep.png" size="6480" user="Main.FerencSikler" version="2"
META FILEATTACHMENT attr="h" autoattached="1" comment="" date="1163358698" name="vertices_c.png" path="vertices_c.png" size="5898" user="Main.FerencSikler" version="1"

Revision 22006-11-12 - FerencSikler

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Vertices with low pT tracks

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Vertices with low pT tracks

 
Changed:
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Vertices with low pT tracks Minimum bias Pythia p+p events at 14 TeV . Generated, simulated and reconstructed with CMSSW_1_2_0_pre1.
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Minimum bias Pythia p+p events at 14 TeV. Generated, simulated and reconstructed with CMSSW_1_2_0_pre1 with special code for low pT reconstruction.
 
Changed:
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Vertex resolution Distribution of vertex residuals with the standard setting (PtMin =1GeV/c) and the low pT setting (PtMin =0).
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Changed:
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The resolution has strong multiplicity dependence, shown here as function reconstructed track multiplicity NRecTracks .
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Vertex resolution

Distribution of vertex residuals with the standard setting (PtMin=1GeV/c) and the low pT setting (PtMin=0).
 
Changed:
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Multiple vertices Distribution of the number of reconstructed (charged pixel) tracks for several NVertices values is shown, that is for different number of found vertices. The following four plots are done with different vertex reconstruction parameters in RecoPixelVertexing /PixelVertexFinding/data/PixelVertexes.cff (ZSeparation, NTrkMin , PtMin ).
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resolution.png
 
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* Standard parameters: Only high multiplicity events give vertex.
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The resolution has strong multiplicity dependence, shown here as function reconstructed track multiplicity NRecTracks.
 
Changed:
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* Lowering PtMin to 0: Now all tracks take part in vertex finding. Even low multiplicity events give a vertex, if, say, NRecTracks > 8.
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multidep.png
 
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* Even looser: Lowering NTrkMin to 2. This choice gives vertex to very low multiplicity events, but at the same time many events will have multiple vertices.
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Multiple vertices

 
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* Even looser: Increasing ZSeparation to 0.5 cm. A possible cure of the previous problem.
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Distribution of the number of reconstructed (charged pixel) tracks for several NVertices values is shown, that is for different number of found vertices. The following four plots are done with different vertex reconstruction parameters in RecoPixelVertexing/PixelVertexFinding/data/PixelVertexes.cff (ZSeparation, NTrkMin, PtMin).

Standard parameters

Only high multiplicity events give vertex.
vertices_c.png

Lowering PtMin to 0

Now all tracks take part in vertex finding. Even low multiplicity events give a vertex, if, say, NRecTracks > 8.
vertices_b.png

Even looser

Lowering NTrkMin to 2. This choice gives vertex to very low multiplicity events, but at the same time many events will have multiple vertices.
vertices_a.png

Even looser

Increasing ZSeparation to 0.5 cm. A possible cure of the previous problem.
vertices.png
  -- FerencSikler - 12 Nov 2006
Changed:
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META FILEATTACHMENT attachment="vertices.png" attr="h" comment="" date="1163353531" name="vertices.png" path="vertices.png" size="6651" stream="vertices.png" user="Main.FerencSikler" version="1"
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META FILEATTACHMENT attr="h" autoattached="1" comment="" date="1163358659" name="vertices.png" path="vertices.png" size="6651" user="Main.FerencSikler" version="1"
META FILEATTACHMENT attr="h" autoattached="1" comment="" date="1163358918" name="resolution.png" path="resolution.png" size="4461" user="Main.FerencSikler" version="1"
META FILEATTACHMENT attr="h" autoattached="1" comment="" date="1163358738" name="vertices_b.png" path="vertices_b.png" size="5988" user="Main.FerencSikler" version="1"
META FILEATTACHMENT attr="h" autoattached="1" comment="" date="1163358685" name="vertices_a.png" path="vertices_a.png" size="6711" user="Main.FerencSikler" version="1"
META FILEATTACHMENT attr="h" autoattached="1" comment="" date="1163358646" name="multidep.png" path="multidep.png" size="6480" user="Main.FerencSikler" version="2"
META FILEATTACHMENT attr="h" autoattached="1" comment="" date="1163358698" name="vertices_c.png" path="vertices_c.png" size="5898" user="Main.FerencSikler" version="1"

Revision 12006-11-12 - FerencSikler

Line: 1 to 1
Added:
>
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Vertices with low pT tracks

Vertices with low pT tracks Minimum bias Pythia p+p events at 14 TeV . Generated, simulated and reconstructed with CMSSW_1_2_0_pre1.

Vertex resolution Distribution of vertex residuals with the standard setting (PtMin =1GeV/c) and the low pT setting (PtMin =0).

The resolution has strong multiplicity dependence, shown here as function reconstructed track multiplicity NRecTracks .

Multiple vertices Distribution of the number of reconstructed (charged pixel) tracks for several NVertices values is shown, that is for different number of found vertices. The following four plots are done with different vertex reconstruction parameters in RecoPixelVertexing /PixelVertexFinding/data/PixelVertexes.cff (ZSeparation, NTrkMin , PtMin ).

* Standard parameters: Only high multiplicity events give vertex.

* Lowering PtMin to 0: Now all tracks take part in vertex finding. Even low multiplicity events give a vertex, if, say, NRecTracks > 8.

* Even looser: Lowering NTrkMin to 2. This choice gives vertex to very low multiplicity events, but at the same time many events will have multiple vertices.

* Even looser: Increasing ZSeparation to 0.5 cm. A possible cure of the previous problem.

-- FerencSikler - 12 Nov 2006

META FILEATTACHMENT attachment="vertices.png" attr="h" comment="" date="1163353531" name="vertices.png" path="vertices.png" size="6651" stream="vertices.png" user="Main.FerencSikler" version="1"
 
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