Code Versions

• We need to be aiming to run p11.08 online when we come back after the shutdown. Marumi has checked that with the new features (non-linearity and NADA) switched off, he gets exactly the same results as with the old version of the calorimeter unpacker. The new unpacker requires trigger list changes - Marumi and Terry to sit down with Elizabeth. Testing of the physics effects of the new calorimeter features by the relevant tool authors can (and should) then begin in earnest. L3 muon should just check that none of the "offline" changes have adversely affected performance in p11.08.
  Note added Friday 14th June: It has been found that the tools.rcp entry for the new unpacker in the p11.08 version of trigdb_scripts is wrong and has to be corrected. This will happen in p11.09, which is currently building and is expected to converge over the next few days. Therefore, p11.09 will be the version to be run online.
• p11.09: Jon "you don't do development in the production branch" Hays has improved the robustness of the new dynamic l3fanalyze and it is now ready for public use. He in the process of implementing an "online/offline" label, which will allow copies of both on- and offline versions of the roottuple to be produced when running on real data. This will facilitate direct comparisons of on- and offline results needed for verification.
• p12.00.00 target date is confirmed as 1st July 2002! We need to be ready. Please see the latest version of the p12 plan for level 3 algorithms and respond if your name still has a "?" mark against it!

Preparations for running after the shutdown

L1CAL is now instrumented to eta of 2.4, which will give a factor of approx 3 in rates for cal triggers. In addition, we would like to come up with a proposal for electron triggering that will give satisfactory rejection up to a lumi of around 4E31 (a factor of two higher than previous best). At 2E31 CEM(1,10) before the shutdown for eta<0.8 ran at around 50Hz. Therefore we want to be able to accomodate an L1 rate for this trigger of around 300 Hz. (This is realistic given some rejection at L2 in the not too distant future.) Assuming we can tolerate a rate to tape of around 10-15 Hz for this trigger we are looking for rejection of around 30 at L3 (wrt L1). In this context we discussed:

• Strategy for stand-alone calorimeter filters for electrons: Ulla Blumenschein:
  • For example a rejection of 27 could be achieved by moving the EM_HI threshold to 30 GeV and the EM_HI_SH threshold to 20 GeV.
  • Variation of shower shape with eta is not too dramatic. In the short term we can live with shower shape cuts that are constant with eta. For p12 we'll need something a bit more sophisticated.
  • In order to give some efficiency at lower E_T and to give redundancy at high E_T, we need an investigation of stand-alone track filters, or running a script consisting of a standalone track filter .AND. a calorimeter filter. Track matching to clusters is further away.
• Primary vertex readiness for online running: Chris Barnes.
  • The version available in p11 is fully tested and works well enough to warrant being tested online.
  • Improved performance is achieved with Chris's modified version, which uses a p_t weighted histogram of the z_0 of all tracks. This will be available in p12 and Chris is investigating other ideas that might do even better.
  • W->munu is even more difficult than Z->mumu. Chris will include this in the samples he uses to measure performance.

Andre asked that the cps presentation promised for this meeting be postponed. But we'll expect it to happen next week without fail!

Summary of Probable Trigger List Changes Needed

• Technical changes that should not change performance of tools (first two agreed by Trigger Board 12th June 2002):
  • Calorimeter unpacker.
  • Electron isolation calculation to be switched off.
  • Modify definition of tau tool term to ensure all parameters are defined in the trigger list.
• Changes to be proposed for Trigger Board approval at 19th June 2002 meeting:
  • Change E_T thresholds for calorimeter stand-alone electron filters.
  • Add stand-alone track filter and/or track + calorimeter filter to maintain efficiency for lower E_T electrons.
  • Add stand-alone track filter for single muon triggers. This will be in parallel to the already existing L3Muon filters, but would need a separate L1/L2 bit, because the aim would be to have a high rejection at L3 and therefore avoid having such a large prescale at L1. (We are not "allowed" to have prescales at L3, which would be the more natural way of achieving this.)
  • Run L3 jet and electron filters using track-based primary vertexing in duplicate L3 scripts.

Scribe: Terry "the term `an average idiot' is a synonym for the 1st person singular personal pronoun" Wyatt.