L2gamma2008 notes

L2gamma2008 trigger strawman

10/23/2007

Before I put alot (any) time in on the L2gamma trigger for 2008, I'm putting up a strawman proposal.  Here are some of the constraints that I noted during the analysis meeting --

  1. L2gamma will have one trigger bit assigned
  2. So we can't run seperate instances of the algorithm as in 2006.
  3. Plan to run two thresholds: 6 GeV in the EEMC, and 7-8 GeV in the BEMC
  4. Goal is 5 Hz trigger rate summed over both calorimeters
  5. Prefer a smaller tower cluster, eg 2x1 (but 2x2 acceptable?)

In 2006 and 2007, the L2gamma trigger searched for the first cluster which satisfied the trigger requirements: high tower above one threshold, 3x3 cluster patch above a second threshold.

Strawman proposal for 2008 is attached as a PDF.  Things which are relatively "settled" have a yellow background.  Things which aren't have a green background.  In the latter category are things like what do we want to save at L2 in terms of variables, and whether or not we want the flexability to do an isolation cut at L2.

Outcome of discussion on gamma phone

10/24/2007

  1. Use a 2x2 cluster, absent simulation which shows good efficiency with 2x1.
  2. Towers belonging to cluster will be identified by denoting which diagonal tower adjacent to the seed tower belongs to the cluster.
  3. Code should have the option to correct the cluster ET based on vertex position as determined by the BBC
  4. L2vertex algorithm is a nice project looking for a home...
  5. Discussed isolation cut as an alternative to raising thresholds during the run.  Met with less resisitance than usual.  Time permitting, this capability should be added to the trigger code w/ appropriate montoring and such.

Trigger data block offsets

10/25/2007

Date: Thu, 25 Oct 2007 15:11:18 -0400
From: Jan Balewski <jtbalews@indiana.edu>
To: "Djawotho, Pibero Kisa" <pibero@indiana.edu>
Cc: Jason Charles Webb <Jason.Webb@valpo.edu>, ruanlj@rcf.rhic.bnl.gov
Subject: Re: ready?

Hi,
the following offsets has been reserved in L2result array for 2008 run.
Please accept your fate
Jan

#define L2RESULTS_2008_OFFSET_TRG         0
#define L2RESULTS_2008_OFFSET_EMC_CHECK   1
#define L2RESULTS_2008_OFFSET_JPSI        2
#define L2RESULTS_2008_OFFSET_UPS         8
#define L2RESULTS_2008_OFFSET_EMC_PED     14
#define L2RESULTS_2008_OFFSET_GAMMA       20
#define L2RESULTS_2008_OFFSET_DIJET       32

L2gamma LUT for 2x2 clusters

I now have the LUT for 2x2 clusters coded up.  It appears to work --

intializing 2x2 cluster lut for 11TB11
 + cluster position 0 diag jeta=9 jphi=50
   rdos: 11TB11 11TA10 11TA11 11TB10
 + cluster position 1 diag jeta=9 jphi=52
   rdos: 11TB11 11TC10 11TC11 11TB10
 + cluster position 2 diag jeta=11 jphi=50
   rdos: 11TB11 11TA12 11TA11 11TB12
 + cluster position 3 diag jeta=11 jphi=52
   rdos: 11TB11 11TC12 11TC11 11TB12

...

intializing 2x2 cluster lut for 11TE01
 + cluster position 0 diag jeta=1 jphi=53
   rdos: 11TE01 11TD02 11TD01 11TE02
 + cluster position 1 diag jeta=1 jphi=55
   rdos: 11TE01 12TA02 12TA01 11TE02

...

next step is to setup input parameters, seed thresholds and clustering thresholds.