Craft09 Visual Summary and Efficiency Trackermaps

Giuseppe Zito : Infn Bari Italy

Giuseppe Zito , Infn Bari

Index

- Craft09 Visual Summary

-How this was created in one week (instead of the month needed for craft08 data).

- Efficiency trackermaps

Craft09 Visual Summary

Hit occupancy for all biggest runs(44 runs with 100 files or more)

Only first 100 files processed foreach run (random selection).Allows easy comparison betweenruns.

promptReco datasets used.Rechits taken from ctfWithMaterialTracksP6

“Summary trackermaps” obtainedprocessing many runs areavailable in the last 3 rows

Craft09 Visual Summary

http://cmstac05/event_display/vis_sum/craft09index.html

Available from:

and

http://cmsdoc.cern.ch/~gzito/temp/view/craft09index.html

From the visual pattern we can classify the runs in 5 groups

1. 108526-108686 Noise in TEC-z TEC+z TOB; no mag.field;peak mode;2. 109046-109624 Noise in TEC-z ; mag. field on;peak mode;3. 109718-109897 Noise in TEC-z; no mag. field;peak mode;4. 110308-110315 No noise; no mag. field ;deco mode;5. 110397-111130 No noise; mag. field on; deco mode;

Inside a group trackermaps almost identical. The sum of all trackermapsIn a group shows the main features of the group.

Group1:no mag. field; noise in TEC+z, TEC-z,TOB;peak mode.

Group2: mag. field on; noise in TEC-z;pek mode

Group 3 : no mag. field; noise in TEC-z;peak mode

Group 4 : no mag. field; no noise;deco mode

Group5 : mag field on; no noise,deco mode

Noise in TEC-z

Another summary trackermap shows noisy modules (here in TEC –z forgroup3). It is a very small number of modules. Their position changeswhen mag. field is on.

Noise in Tec -zExample of event with fake track in Tec -z

Noise in TEC -z

Selecting all events with a track hitting one of these noisy modules, you get typically 30 events in a run with noise and only 5 in a run without noise. A scan of the 30 events shows that in fact 25 contain a fake track.

So the most probable explanation of why we have these few noisymodules (in the cluster occupancy trackermap we have many more)is that these modules appear by chance to make a good track.This explains also because the presence of mag. field changes theposition of these modules.

How this visual summary was created

All trackermaps are now computed with the same script by Nikita that creates the event selection described in:

https://twiki.cern.ch/twiki/bin/view/CMS/SWGuideTrackerVisualizationInGlobalRuns

This script launches automatically a root macro on each file.In this way I can manage to process around 1000 files of promptReco datain less than an hour(I don't use skims)

This has enabled me to have this data only 1 week after Craft09 end (instead of the month needed with Craft08 data where I used CMSSW analyzers)

Testing the root macro that computes the trackermap I came across the possibility to use invalid rechits to create efficiency trackermaps

Efficiency trackermaps

Efficiency trackermaps are summary trackermaps (i.e. you buildthem using the data from many runs because it needs a largestatistics: at least 1000 files to allow the efficiency computationalso for modules hit by very few tracks (I require a minimum of10 tracks to compute the efficiency)

They are computed without the need to reconstruct again theevent, using the information available in prompReco datasets.

In principle they could be computed also using DQM root filesprovided that a new TkHistoMap is added. This should containInformation about invalid rechits distribution.

In fact the efficiency of a single module is computed as Number_of_invalid_rechits/total_number_of_rechits

Efficiency trackermaps : limitations-Depends on the track finding algorithm- Can be computed only for modules where the algorithm makes guesses.- For ctfWithMaterialTracksP5 this includes around half the tracker

Invalid rechits distribution for ctfWithmaterialtracksP5 collection

Efficiency trackermaps Results using the first 10 runs of group5

Numbers near a layer show mean module efficiency in the layer.

Efficiency trackermaps: are the results reliable?

Yes• all well known holes and inefficient modules are found• the mean efficiency in a layer agrees with systematic studies done extrapolating good tracks(Keith).•The modules in barrel layer show the phi dependency found in Giovanni study (see for example TOB L3)

Efficiency trackermaps:does the pattern change in different periods?

Efficiency trackermap from the 10 runs in group2: can you spot the differences?

Efficiency trackermaps:does the pattern change in different periods?

Yes and the changes are connected to changes in tracker behaviour!

Answer:1) Tib L3 has a shadow on the first half due to the fact that a blockof modules was off in a single run.2) In TEC-z 1,2,3,5 the noise present has inhibited to the algorithmthe discovery of a small group of inefficient modules.This probably means that the noise in TEC-z has not only created alot of fake tracks (of no use to find inefficient modules) but has alsoaltered the reconstruction of cosmic tracks in such a way that thesecan’t any more find inefficient modules.

3)The Pixel has also changed a lot: can Petra confirm this big changeIn efficiency?

Summary

A Visual Summary of hit occupancy trackermaps can now be built in a few days using promptReco datasets

A new summary trackermap that is able to show the efficiency in about half theSiStrip Tracker modules can be computed without need to reconstructagain tracks. In theory we can built it directly from DQM rootfiles provided that we store the distribution of invalid rechits in a TkHistoMap.