Deltadot: Tracking and Vertexing Update

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Deltadot Tracking and Vertexing Update

• Vertexing methods
• 2 min ladder sample
• 6 min multi-injection DNA sample
• Status and current work

Phil Lewis, Tim Scanlon
04 Sept 2006
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Vertexing methods
Deltadot Tracking and Vertexing Update
Tracks assigned to nominal vertices using
distance of closest approach and associated
error.
OR
Vertex positioned to minimise distance from hits
to refitted tracks. (uses MINUIT).
Vertex positioned to minimise closest approach of
tracks. (inverts 2D matrix)
Iterative vertex then removes any tracks with bad
chi-squared and recalculates.
Phil Lewis, Tim Scanlon
04 Sept 2006
3
Ladder Sample
Deltadot Tracking and Vertexing Update
Phil Lewis, Tim Scanlon
04 Sept 2006
4
Ladder Sample
Deltadot Tracking and Vertexing Update
Track velocities
Phil Lewis, Tim Scanlon
04 Sept 2006
5
Ladder Sample
Deltadot Tracking and Vertexing Update
Refitted track velocities
Phil Lewis, Tim Scanlon
04 Sept 2006
6
DNA Sample
Deltadot Tracking and Vertexing Update
Phil Lewis, Tim Scanlon
04 Sept 2006
7
DNA Sample
Deltadot Tracking and Vertexing Update
Track velocities
Phil Lewis, Tim Scanlon
04 Sept 2006
8
DNA Sample
Deltadot Tracking and Vertexing Update
Refitted track velocities
Phil Lewis, Tim Scanlon
04 Sept 2006
9
Status
Deltadot Tracking and Vertexing Update

• tracking and vertexing are working well.
• (but need to tailor cuts for each data sample
• kalman filter cuts, track quality cuts,
• criteria for assigning tracks to nominal
  vertices, etc.)
• ? need more data (ladder samples?)
• missing tracks seem to be due to small
  amplitude
• track lying in region of large amplitude
  track.
• working on
• tool to find nominal vertices.
• how to optimise cuts.
• improvements to track finding
• (calculation of amplitude, error calculation,
  etc.)

Phil Lewis, Tim Scanlon
04 Sept 2006