Issues and Clarifications  I

Disclaimer

  
   Here are the Questions that you "the DØ Collaboration" made so far.
   The Questions are yours, the Answers and the Errors are mine.
   Some issues that require less lengthy explanation are dealt with in the page Q & A
NEXT Manuel I. Martin
ISSUE
... how will the L2STT and L2CFT deal with duplicate tracks. ...
The second issue, duplicate tracks, arises because very often the same L1CTT track candidate is sent to two sextants. Thus it is possible for the L2CFT to receive the same track twice. According to Manuel each track can be uniquely identified with it's coordinates so that the L2CFT can cull the duplicates. The STT group and the L2CFT groups should consider this issue. Note that this may place another load on both systems.
CLARIFICATION
At this moment, the goal is to send to the L2STTpp only those tracks from each Sextant which belong to that Sextant. To understand the problem of possible duplcated tracks it is necesary to understand how the Sextants information is obtained and how .
That said, my personal choice would be to maintain the L2CPS Axial links to the L2PS as described in the CTT Documment (see pages 6, 14 and 29 through 33) with some minor changes. Maybe I am wrong, but I think it is important to maintain the Quadrant organization of the data. Furthermore, I do not see as very difficult to make a match between the track information arriving from the L2PSpp and the L2STTpp in the L2 Global.
The changes I suggest affects mainly the data that the Broadcaster Boards (at the Quadrant level) send to the L2PSpp. The Data Format presented in the CTT Documment in Pg. 27 is reproduced here
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The new Data Format is shown below.
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The changes consists in rearranging the position of some fields and:
  • Eliminate the bit "V" with the condition that the "Relative Fof the Cluster" starts with [0001] (code [0000] will be invalid)
  • Introduce the bit "P". P=0 if the track associated with the cluster is contained in the same 4.5 degree sector, P=1 otherwise.
  • The pair of bits [P,S] indicates if the track is contained in the previous sector [1,1] or in the next sector [1,0].
  • Include the Extended Pt of the associated track.
These changes allow for an easier correlation between tracks sent by the L2STTpp and the tracks associated with the clusters.
  Copyright © 1999
  This Page was created by Manuel I. Martin,Tuesday, June 08, 1999