1. NKS meeting 2007/02/28 Tohoku Univ. Kyo Tsukada

2. Vertical tracking The vertical tracking and horizontal tracking are depend on each other. –But now, the vertical tracking is done assuming that the horizontal tracking correctly finish. A vertical tracking should be done without the information of hodoscope. –If the resolution from DC is better than that of hodoscope, it may be not important to including the information of hodoscope into the tracking. –If the resolution from DC is worse than that of hodoscope, the information from hodoscope may be useful for the tracking, especially at the beginning of the parameter tuning.

3. Method More than three hits of four stereo wires are required. Two z candidates are found by the horizontal trajectory. The relation, z=a+bx, is assumed. From the least  2, most probably track is selected.

4. Analyzer DCAnalysis::TrackSearch() –Horizontal tracking –SDC, CDC4,5,8,9,12,13 are used. DCAnalysis::VerticalTrackSearch() –Vertical tracking –CDC6,7,10,11 are used. –Z information of vertical wires are estimated from vertical tracking. PTrack::calcObservables() –Calculating the Time of flight, flight length, , mass, and so on. –The vertical angle of the track is estimated from, PTrack::calcVerticalTrack() Result of DCAnalysis::VerticalTrackSearch() OH.

5. Run conditions Run394: –XT curves are well studied by Han. –In trigger, EV were required. Run698: –XT curves are not studied. The same with run394 is used. –In trigger, EV were not used. XT curves for stereo wires are assumed to be same with next wire. In this slides, hodoscope are not included in the tracking.

6. Some results… Run394: –#event : 1069095 –#HDCTrack/#event : 0 : 41.9%, 1 : 42.7%, 2 : 14.6%, 3 : 0.7%, 4 : 0.04% (total : 793185) –#VDCTrack / #HDCTrack : 78% –#PTrack : 642386 ( 81% of #HDCTrack ) –#VDCTrack in PTrack : 80% –#VPTrack in PTrack : 76% –#PVertex : 112526 ( 10.5% of #event )

7. Some figures… Drift length derived from trajectory. Z-position at OHVL4. Black : from OH Red : from DCTrack ( not include Hodo )

8. Some results… Run698: –#event : 954780 –#HDCTrack/#event : 0 : 31.1%, 1 : 40.7%, 2 : 27.3%, 3 : 0.8%, 4 : 0.05% (total : 935433) –#VDCTrack / #HDCTrack : 87% –#PTrack : 769191 ( 82% of #HDCTrack ) –#VDCTrack in PTrack : 89% –#VPTrack in PTrack : 89% –#PVertex : 197897 ( 20.7% of #event )

9. Z-position at OHVL4. TOP : raw BOTTOM : w/o EV Black : from OH Red : from DCTrack ( not include Hodo ) Z-position ratio at OHVL4. Ratio (isEV)/(w/oEV) Black : from OH Red : from DCTrack ( not include Hodo )

10. Conclusion うまくいか～ん。。。