Minutes of E895 Meeting

Held at LBL 50A-5132, 1:30pm July 16, 1997

In attendance:  Dieter Best, Bill Caskey, Jerry Chance, Heng Liu, Gulshan Rai,
Sergei Panitkin, Chris Pinkenburg (Phone), Hans Georg Ritter, Ron Soltz, Nathan
Stone, James Symons 

GR announced that Art Poskanzer and Sergei Voloshin would give a presentation
on flow.

News Items and Discussion

GR:	Reported on recent results from Jim Draper.  The new distortion file
straightens out laser tracks.  Hooks are not completely gone and the lasers may 
not be in the right position. 

   ---RS: Where is distortion file kept?  

   ---NS: In CVS file on SSEOS cluster, will send location by email. 

DB:	Reported on study of dy residuals using tracks from 6GeV data averaged
over pad rows. Applying corrections using the old distortion file doesn't do
much, and new distortion file doesn't do much either (and may make things a
little worse). Laser tracks will be more sensitive. 

   ---CP: What about using beam tracks?  

   ---GR: Could you look at them?

   ---CP: OK

DB:	Working on btf issues (hits associated with multiple tracks, etc.). 
Not much progress to report because of time needed to debug software. 
However, one hit can now be associated with as many as 5 tracks.  Preliminary
studies indicate that 

	1% of hits are associated with more than one track in 2GeV data.

	No more than 2 tracks shared one hit in 2GeV data

	As many as 8 tracks had shared a hit in 8GeV data!

Tracking time has increased mysteriously.  Changing hits table has
broken the code.  Fixing it. 

NS:	Has run new set of dE/dx files with new version of BTF.  Various bugs
have been fixed and results for btf and jtf are now similar.  He will hand back
code to DB for fine tuning.  dE/dx landau fluctuations appears to be around 
30-40% (not dE/dx resolution)

NS:	Showed postage stamp plot of y residual versus x for fitted tracks. 
This may indicate a t0 problem  Different sticks have different t0s. 

   ---RS:  has anyone looked at pad by pad variation?

   ---CP:  I do things pad by pad.

   ---RS:  How big are pad by pad variations?

   ---GR:  No one knows.

   ---CP:  Away from center, we quickly run out of statistics.

NS:	Has updated btf and hit-finders.  New versions no longer have bit-mapped
switches which needed kumacs to operate.  he reported that Mike Lisa has created
new tables to provide same functionality.

GR:	introduced Art Poskanzer from LBNL and Sergei Voloshin (MEPhi, 
Heidelberg and Pittsburg)

Art and Sergei gave a nice discussion of flow, emphasizing the importance of
all workers using common methods of analysis. Vu-graphs are available from
Gulshan. 

RS:	Has anyone used the 910 tracker on 895 data?

   ---DB:	No.

SP:	LINUX box has arrived and will be installed.

BC:	UCD working on dE/dx

JC:	Has refined and updated the MUSIC code.  He needs some help with
	makefiles. 

HL:	Working on strategy for compression of hits table.  A plan will be
	presented next week. 


	Prepared by J. Symons