2. Object Oriented reconstruction of the CMS muon chambers CHEP 2000 7-11 February, Padova Annalina Vitelli - INFN Torino

3. Items The CMS Muon Chamber Detector What the software has to do? A glance to the past... Software design First applications Conclusions

4. The CMS Muon Chamber Detector Muon Identification Muon Trigger p measurement... Muon Identification Muon Trigger p measurement...

5. What the software has to do? GEANT Hits access Digitization: detector response (time) Calibration : time-space conversion Local reconstruction : reconstruction of track segments inside a chamber Standalone fit : p measurement using only the muon system

6. A glance to the past... September 1998: ORCA_1 release  GEANT3 access (geometry+hits)  digitization  local reconstruction April 1999 : ORCA_2 release  complete integration to CARF  first track fit prototype November 1999 : ORCA_3 release  first experience with a Objectivity DB  extensive application of the "on demand" CARF mechanism

7. The Software design This section could be called: The Muon Chamber & The TrackFinder an example of OO A&D process

8. The way we proceed is: Build the model describing a scenario find the basic objects identify their responsibilities define the relations among objects

9. The scenario: find a track from a defined seed Starting from the first layer, then: find the compatible DetUnit in this layer for each DetUnit check the compatible clusters add the best cluster to the track go to the next layer if no cluster are found restart from the next layer

10. Who? Digitization and local reconstruction should be provided by the chamber the output of the local reconstruction are objects "detachable" from the detectors these objects are used to perform physics reconstruction and the analysis of the "Event"

11. How? Looking at the chamber: we want to be fast! we want clusterize, digitize etc., just the interesting stuff at next step we don't want to re-compute what has been done before...

12. The Chamber (detector reconstruction level) The three actions under the chamber responsibility are done only on demand The three actions under the chamber responsibility are done only on demand Chamber Detector Element Local reconstruction Digitizer SimHitLoade r

13. Track Finder (event reconstruction level) T he fit is performed only on demand The regional reconstruction can be easily provided using the navigability of the DetUnit and the "on demand" reconstruction mechanism T he fit is performed only on demand The regional reconstruction can be easily provided using the navigability of the DetUnit and the "on demand" reconstruction mechanism Event User Rec Detector Element Rhit Tracks

14. First applications The first application of the OO reconstruction package was the analysis of the data taken in the August 1999 test beam in November 1999 a production of Monte Carlo events was performed using the digitization software to store the data in a objectivity DB, and the reconstruction packages to provide the muon tracks fit

15. Conclusions After 1.5 year the muon software has been done with most of the requested functionalities The "on demand" mechanism was clearly useful to solve most of our requirements The extensive use of the code allowed to test, besides its performances, the versatility and the handiness of the software!