[Brahms-dev-l] RE: vertex calibrations

From: Johnson, Erik B <ebj@ku.edu>
Date: Thu Sep 16 2004 - 16:48:44 EDT
Brahms,
   I have been working on the ZDC vertex efficiency issue for the 63GeV data.   I decided to go ahead and determine new slew parameters and vertex offsets for the 63GeV data.  I committed parameters at runs
11298
11311
11331
11377
11422
11459
11491
11546

In addition to this, I developed a new method for generating the ZDC vertex. JH via Hiro showed me a plot that shows the ZDC vertex efficiency is fairly low at the most central collisions.  The old method for determining the vertex limits the efficiency, so I made a slight change in the method.  You can see what I did at 
http://www4.rcf.bnl.gov/~ebj/ZDCefficiency/zdcefficiency.html
if you want a better picture of the plots go to 
http://www4.rcf.bnl.gov/~ebj/ZDCefficiency/

if there are no objections by the end of tomorrow I will commit the new code to CVS.

Erik




-----Original Message-----
From:	Hironori Ito [mailto:hito@rcf.rhic.bnl.gov]
Sent:	Thu 9/16/2004 3:05 PM
To:	Catalin Ristea; Truls Martin Larsen; Johnson, Erik B
Cc:	Djamel Ouerdane; flemming videbaek; Sanders, Stephen J
Subject:	vertex calibrations
Hello.  About the calibration of vertex detectors (BB and ZDC), here is 
my proposal.

1.  For BB.
    After looking and checking codes and calibrations for some runs, the 
calibrations are already quite good.   However, since there is a new 
parameter in BB vertex offset (useall or something), we need to commit 
them if we want to use that option.  So, the suggestion is

    A.  Find run numbers which have bb calibrations.  Use 
http://pii3.brahms.bnl.gov/daq-cgi-bin/cgiCalibrationDB.perl page.  
Unless there are only fews runs with commited calibration, you only need 
to check those runs you find in this page.
    B.  Run BbVtxOffset.C script  with SetUseAllAsBest option.
    C.  Check the offset values as well as (bb) tof plot.  From the tof 
plot, you can easily find a bad tube if there is one.  If you are 
satisfied, commit them.

2.  For ZDC.
    Again, you just need to check offset here since the calibration done 
by Erik looks already good.   However, since there is no new parameters, 
you don't need to commit the calibration if they are already good.  Only 
if the calibration in the database is bad, commit a new calibration.


If you have any question, please let me know.

Hiro





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Received on Thu Sep 16 16:49:07 2004

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