Global Tracking Software Status H. Greenlee Run II Meeting May 12, 2000

Outline Current tracking performance –Efficiency –Resolution –Timing Global tracking review Tasks –Milestones –Active projects –Future projects

Acceptance Found Tracks Missed Tracks Z  mb events

Acceptance Found Tracks Missed Tracks Z  mb events

Tracking Performance Current (t87) tracking performance can be found at the following web page: 27apr00 t run bg #ev CPU CLK mem swp tm rf pe pTt # mc eff misr fake fcsq mcsq nmsm pzmm pzmm zmu pzmm pzmm zmu pzmm pzmm zmu pzmm pzmm zmu pzmm pzmm zmu pzmm* pzmm* zmu pzmm pzmm zmu pzmm pzmm zmu

Efficiency & Fakes

CPU Time by Step

Historical CPU Time

Global Tracking Review A review of global tracking software was conducted by Marc Paterno and Jim Kowalkowski, beginning on Feb. 4, The review report was made available on Feb. 29, GlobalTracking/index.html Review and report concentrated on efficiency and speed issues.

Global Tracking Review Problems/Recommendations Problems/recommendations. –Excessive copying. Return by value instead of by reference. Converting objects from edm to trf format. Use of activate/deactivate. –Use of STL. Choice of container class (e.g. map<>). Using STL vector without reserve(). STL for fixed size objects. –Duplication of utilities (e.g. linear algebra). –Trf ptr<> smart pointer class. Can be made lighter weight. Get better locality of reference by storing reference count with object.

Problems/Recommendations (cont.) –Parameters. Obs files have no bookkeeping. Migrate user settable parameters in rcp. Hard-coded constants. –Profiling.

Profile Results Profiling was first successfully done in t86. –Works on sgi or linux (using special build). Results –One thing that was learned is that trf initialization was taking 25-50% of the cpu time, depending on event complexity. In t89, trf initialization overhead has been reduced by a factor of six by combining the six global tracking framework packages into a single framework package.

June Milestones

Active Projects Cosmic ray tracking (A. Goussiou). Track refitting/interacting propagator (V. Kuznetsov/D. Adams). Track-finding using 2D clusters in CFT (A. Kharchilava, J. Krane, H. Greenlee). Fixing high-pT inefficiency (H. Hildreth, B. Knuteson). Tracking in non-uniform magnetic field (O. Peters/K. Bos). SMT tracking optimization (S. Kulik).

Cosmic Ray Tracking Needed for cosmic ray commissioning. Not necessarily needed for production release. Trf modifications needed to allow propagation of tracks that traverse the detector (done). Next step is construction of cosmic tracking paths. A. Goussiou

Track Refitting and Interacting Propagator Uses of interacting propagator. –Refit to get optimal parameters at each end of track. –Can get optimal fit parameters at any point outside the tracking volume by propagating (no refitting). –Can get optimal parameters at any point inside the the tracking volume by refitting. –Can better account for passive material and material that is not thin or not close to a sensitive surface. Status: –On by default for CFT central only in t89. SMT turned off because of speed. –Will be turned on for all steps when speed problem is fixed (perhaps next release). V. Kouznetsov

Parameter Resolution and Pulls at DCA Normal Fit Refit ResolutionPull

Parameter Resolution and Pulls at DCA ResolutionPull Normal Fit Refit

Parameter Resolution and Pulls at DCA ResolutionPull Normal Fit Refit

Parameter Resolution and Pulls at DCA ResolutionPull Normal Fit Refit

Parameter Resolution and Pulls at DCA ResolutionPull Normal Fit Refit

Chisquare at DCA Normal Fit Refit Fit    dofMatch  

Parameter Resolution and Pulls at Outer Layer ResolutionPull Normal Fit Refit

Parameter Resolution and Pulls at Outer Layer ResolutionPull Normal Fit Refit

Parameter Resolution and Pulls at Outer Layer ResolutionPull Normal Fit Refit

Parameter Resolution and Pulls at Outer Layer ResolutionPull Normal Fit Refit

Parameter Resolution and Pulls at Outer Layer ResolutionPull Normal Fit Refit

Chisquare at Outer Layer Refit fit    dof Refit Match  

Track finding in CFT using 2D clusters Combine axial and stereo CFT clusters into 2D clusters (effectively space points). –Already done in SMT. Should dramatically speed up tracking in overlap region by concentrating on CFT hits near ends of detector. Will also be tried in CFT central region – may or may not speed things up. A. Kharchilava, J. Krane

CFT 2D Cluster Project Status Define class for CFT 2D cluster (released). Define CFT 2D cluster chunk (released). Write CFT 2D cluster framework package (released). Define TRF 2D cluster and hit classes (released). TRF CFT detector description in terms of 2D barrels (released). Convert CFT clusters into TRF clusters and add to TRF detector description (in cvs). Overlap region cluster filters (in cvs). Initial fitters (not done). TRF paths (not done).

Tracking in Non-uniform Magnetic Field cvs packages –mag_field: Contains abstract magnetic field interface and several concrete magnetic fields. –tim: Numerically solves equations of motion for non- uniform field motion using Runge-Kutta method. Borrowed from ATLAS. –tim_interceptor, tim_interface: These packages adapt ATLAS propagation code for D0 and trf interfaces. Status –tim code can currently propagate track parameters and error matrices between any two surfaces used in D0 tracking (code in cvs). –Still being verified. O. Peters, K. Bos

Future Tasks Tracking with inefficiencies. Tracking with non-ideal geometry. –Need to add hooks to tracking code. –Do alignment. There will be a continuing effort at optimization and speed up. Tracking in gap region (between overlap and forward). Tracking in muon system and (possibly) other detectors.