1 / 20

NKS Vertical Tracking( and etc) written at 2007/08/15

NKS Vertical Tracking( and etc) written at 2007/08/15. Tohoku Univ. Kyo Tsukada. Method. More than three hits of four stereo wires are required. Two z candidates, z1 and z2, are found by the horizontal trajectory. The relation, z=a+bx, is assumed in local coordinate.

kirkan
Download Presentation

NKS Vertical Tracking( and etc) written at 2007/08/15

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. NKS Vertical Tracking( and etc)written at 2007/08/15 Tohoku Univ. Kyo Tsukada

  2. Method • More than three hits of four stereo wires are required. • Two z candidates, z1 and z2, are found by the horizontal trajectory. • The relation, z=a+bx, is assumed in local coordinate. • From the least c2 method, most probably track is selected in 2^(numofstereohits) tracks.

  3. Analyzer (1) • DCAnalysis::TrackSearch() • Horizontal tracking • SDC1,2,3, CDC4,5,8,9,12,13 are used. • DCAnalysis::VerticalTrackSearch() • Vertical tracking • CDC6,7,10,11 are used. • Z information of vertical wires are calculated from vertical tracking. • PTrack::calcObservables() • Calculating the Time of flight, flight length, b, mass, and so on. • The vertical angle of the track is estimated. The priority is as follows, • Result of PTrack::calcVerticalTrack(). • Z-information of OH as outer-side and the origin as other side.

  4. Analyzer (2) • PTrack::calcVerticalTrack() • Vertical tracking • CDC6,7,10,11, IH and OH are used. • z1 and z2 are already found in DCTrack::VerticalTrackSearch(). • dz of IH and OHH ~ zlen/sqrt(12), OHV ~ 2cm • Z information of vertical wires are estimated from vertical tracking. • ParticleAnalysis::SetTimeZeroCorrection(…) • Correcting the Time of DC by • Time of IH associated a track • Time difference between slow particle and electron. • Tracking and vertical tracking again. • PVertex3D::ConstructVertex() • Constructing a vertex from 3D tracjectories.

  5. Search Nearest Hit • For the killed layer method, DCTrack::SearchNearestHit is important. • Now, it can work even for stereo layers. • We can also get the drift length calculated from trajectory position. •  We can derive the X-T curve of stereo layers.

  6. X-T curves (before adjusting) run1150 Stereo Layers

  7. X-T curves (after adjusting) run1150 Stereo Layers

  8. Resolutions of January data • 915.param : run915 • 908-925.param : run917 • 929-952.param : run940 • 956-968.param : run960 • 972-991.param : run981 • 992-1017.param : run 1006 • 1022-147.param : run1036 • 1051-1071.param : run1065 • 1075-1097.param : run1085 • 1101-1122.param : run1112 • Right figures show the mean and sigma of gaussian fits for the run used to adjust parameters.

  9. Resolutions of all run • Bottom figures show the mean and sigma of gaussian fits for all run. • The time dependence of sigmas are reasonable because of the lack of the chamber gas at the beginning of the experiment. • The mean of the residual is good only for the run used to adjust parameters. • At least, the offset parameters should be corrected run by run.

  10. Plane efficiencies of January data • Bottom figures show the efficiencies for the run used to adjust parameters. • The efficiencies are estimated in the range, 20degree<| angle |. • Right bottom figures are the efficiencies with the distance cut, distance < 1.5*cellsize.

  11. Vertical angular resolution (1) z@OHVL2 from OH z@OHVL2 from OH w/EV z@OHVL2 from DC z@OHVL2 from DC w/EV Run1128-1157 z@OHVL6 from OH z@OHVL6 from OH w/EV z@OHVL6 from DC z@OHVL6 from DC w/EV -0.9 < cosOA < 0.8 z@OHVL2 from OH z@OHVL2 from OH w/EV z@OHVL2 from DC z@OHVL2 from DC w/EV The bump due to EV is clearly seen. z@OHVL6 from OH z@OHVL6 from OH w/EV z@OHVL6 from DC z@OHVL6 from DC w/EV

  12. Vertical angular resolution (2) -0.9 < cosOA < 0.8 Run1128-1157

  13. Vertical angular resolution (3) Run1128-1157 • Vertical distribution for each OH w/ EV. • For OHVL4 and OHVR4, the correspondence between OH and EV are wrong.

  14. Vertical angular resolution (4) Run1128-1157 • By taking the difference of adjacent bins, the resolutions are estimated. • The shadow of EV and the edges of OH are used.

  15. Vertical angular resolution (5) Run1128-1157 • The positions of the edges of EV and the vertex resolutions are estimated. • The width of EV is 5 cm. • From tracking, the widths seems to be little narrow (?). • The sigma is less than 1 cm. Right Left

  16. Vertical angular resolution (6) Run1128-1157 • The positions of the edges of OH and the vertex resolutions are estimated. • The height of OHV is 74.8 cm. • From tracking, the heights seems to be little small (?). • The sigma is about 1 cm. Right Left

  17. Vertical angular resolution (7) Run1128-1157 • The positions of the edges of OH and the vertex resolutions are estimated. • Because the distribution is not flat, the fittings are done for one side of each OH. • From tracking, the heights seems to be little low (?). • The sigma is about 1-2 cm.

  18. Vertex resolutions in 3D • Vertex resolution • The dx is estimated by the difference of the distribution. • I could not find how to estimate the dy and dz. • Right figures show the vertex distributions in target. • If the beam size is negligible, this distributions give dy and dz. Run1150 Run1128-1157

  19. Resolution of Vertical angle • The vertical resolution at target is about 2 mm. • The vertical resolution at OH is about 10 mm. • The radius of OH from origin is typically 120 cm. The angular resolution (dq) is about 8.5 mrad.

  20. Summary • The vertical tracking works well. • For DC tracking, the time information of IH and OH are used. • The plane resolutions are about 500 um for CDC and 300 um for SDC. These values include the tracking resolution. • We should adjust the drift parameters run by run. • The plane efficiency are more than 98% in stable runs. But, in this study, the efficiencies in the forward region are not estimated. • The vertical position resolutions are about 10mm@OH and 2mm@target. • The vertical angular resolution is about 8.5 mrad. • The z-position of the vertex point can be calculated.

More Related