From ryu@rcf2.rhic.bnl.gov Thu Aug 30 13:09:01 MDT 2001 Received: from mailrelay3.lanl.gov (mailrelay3.lanl.gov [128.165.3.1]) by p2hp4.lanl.gov (8.9.3 (PHNE_21697)/8.8.6) with ESMTP id NAA16367; Thu, 30 Aug 2001 13:09:00 -0600 (MDT) Received: from mailproxy1.lanl.gov (localhost.localdomain [127.0.0.1]) by mailrelay3.lanl.gov (8.11.4/8.11.4/(ccn-5)) with ESMTP id f7UJ97d15879; Thu, 30 Aug 2001 13:09:07 -0600 Received: from smtpgw.bnl.gov (smtpgw.bnl.gov [130.199.3.16]) by mailproxy1.lanl.gov (8.11.6/8.11.6/(ccn-5)) with ESMTP id f7UJ97Q20535; Thu, 30 Aug 2001 13:09:07 -0600 Received: from bnl.gov ([130.199.128.163]) by smtpgw.bnl.gov with esmtp (Exim 3.22 #1 ) id 15cXBa-0001i4-00; Thu, 30 Aug 2001 15:09:06 -0400 Received: from rcf2.rhic.bnl.gov (ryu@rcf2.rhic.bnl.gov [130.199.6.81]) by bnl.gov (8.9.2/8.9.2) with ESMTP id PAA15591; Thu, 30 Aug 2001 15:09:05 -0400 (EDT) Received: from localhost (ryu@localhost) by rcf2.rhic.bnl.gov (8.9.3+Sun/8.9.3) with ESMTP id PAA13885; Thu, 30 Aug 2001 15:09:05 -0400 (EDT) Date: Thu, 30 Aug 2001 15:09:05 -0400 (EDT) From: Sangsu Ryu To: , , , , , Subject: Mvd pseudotracker and Bbc Message-ID: MIME-Version: 1.0 Content-Type: MULTIPART/MIXED; BOUNDARY="-559023410-851401618-999198545=:11153" Status: RO This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. Send mail to mime@docserver.cac.washington.edu for more info. ---559023410-851401618-999198545=:11153 Content-Type: TEXT/PLAIN; charset=US-ASCII Dear all, Heonsoo and I started to study vertexing. In attached plot x-axis is z vertex from Mvd pseudotracker and y-axis is Bbc z vertex. It is not very clear but we can see points on y=1*x line over randomly distributed points. Run which this plot is obtained from is 26815-0008. I used event-by-event correction for this but without correction it will give similar distribution because packets used in pseudotracking algorithm are already good before correction is made. Pseudotracking algorithm is from CVS repository except that it will give -9999 when the algorithm fails to estimate z vertex. The source at CVS and current official library will have Bbc vertex in mvd vertex ouput when pseudotracking algorithm fails. So be aware. Even though correlation does not look very good at first glance, we are quite happy with the result which is obtained with minimum effort like a few hours because it means offline software works basically fine even after so many changes since last year. There is much room for improvement also. Calibration can be improved, we can tweak geometry, pseudo tracking algorithm itself can be made smarter using Ju's idea. One thing I have to mention is that I'm not sure about Bbc calibration constant used for this plot. I'll talk to Bbc expert. So I decided to defer sending this mail to mvd list server yet. I hope we can play with it a little bit more (we just get started) to get much better performance. Best regards, Sangsu ---559023410-851401618-999198545=:11153 Content-Type: APPLICATION/PostScript; name="zvertexmvdbbc.zoomout.3sigma.ps" Content-Transfer-Encoding: BASE64 Content-ID: Content-Description: Content-Disposition: attachment; filename="zvertexmvdbbc.zoomout.3sigma.ps" (cut)