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Minutes of E895 Meeting - Aug. 5, 1997
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Participants:

Hans-Georg Ritter (HGR), Gulshan Rai (GR), Nathan Stone (NS), Bill
Caskey (BC), Jessica Kintner (JK), Dieter Best (DB), Heng Liu (HL),
Sergei Panitkin (SP), Mike Lisa (ML), Arun Das (AD), Chris Pinkenburg
(CP), Ron Lacey (RL)   

NS - reported on the status of xdf format software.
	-achieved expected 12% compression
	-event-by-event: can write in a loop, can't read in a loop.
	-will complete dls library in 1 or 2 days
   -also work on CVS system area

HL - finished pack/unpack routines

NS,ML,HG, GR -discussed the structure of the new p/u modules.
	Decided to have two modules only and one switch table.
	hits and tracks p/u will be together.
	NS will work on a track p/u port.

ML - reported on hitfinder development. Changes in dE/dx module, some
	bug fixes. Changes in treatment of "crowded" clusters.
	Needs some fine tuning.
GR - How much time do you need to finalize 2d h.f.?
ML - about a week.

GR - reported on distortion correction. (UCDavis will post relevant
	pictures on the Web)
	-Old distortion correction leads to an S-shape of the laser
	tracks
	-New correction with new ExB term a bit over-compensate and
	still has some S-shape.( Possibly omega*tau term should be changed
	from 4.5 to 6.2(according to reports of Aleph and PEP4.)
	Straight laser tracks gives variations <1mm.
	-Slanted laser track without distortion correction shows some
	kinks. With distortion correction kinks disapeared but some
	distortions are introduced ( "spoon/condor" effects).
ML - Is it reasonable to expect such a dramatic change in omega*tau(6.2)?
     This is related to transverse diffusion and his study shows that
     diffusion is consistent with 4.5.

GR - Agreed that it has to be checked (omega*tau=4.5 for slanted laser
     tracks. It will take couple of days.

Some related discussion follows:ML, NS, CP.

SP - PentiumII box at LBL is ready for test runs. All software is in place.

DB - Reported on the btf status.
	-code doesn't use the distortion correction now. If we apply
	the distortion correction now we will nedd to change the
	tracker.
	-GEANT efficiency study- btf vs jtf. Checking Arun's analysis of
	efficiency. AD in Ohio will do a parallel analysis.
	-uses 6 and 8 GeV hope to finished by the end of the week.
	-less than 1% of hits that are used several times.

ML - Do it with 2d hitfinder please.
   -60% of the hits are not used @6GeV. Why?
	
CP - What is this spike at zero Pz ?	
	 
Discussion by NS,ML,CP,GR,HL,DB, BC. What is the origin of the high
rigidity tracks?

GR - Concluded that that both trackers do similar job in momentum
     reconstruction. 	

DB - showed timing plots for btf and jtf. Concludes that btf works
faster then jtf.

DB - compared dE/dx resolution for both trackers. Concludes that jtf
gives slightly better resolution then btf.

Discussion by NS, BC, JK, GR,DB,CP,ML, AD. Do we understand the
magnitude and the shape of dE/dx vs nhits? Why it's flat at large
nhits? Concluded "No". Suggested to look at dE/dx spectra. Is it a
problem of splitted tracks? 

DB - showed track momentum resolution as a function of momentum.

GR - summarized a situation and open issues with preparation for DST
     production. 
	-t0 correction is not ready
	-more work is needed on software in general
	-distortion correction. Will we apply it?
	-monitoring histograms and software for production. 
	-finalize bad pad list
	-vertex module for btf?

Adjourn