July reprocessing discussion
Summary of Comments Received by Email
ATLAS Reconstruction Meeting
Adam Gibson
June 15, 2010

There are other contributions on the agenda (e.g. from LAr).
And others promised before the meeting (e.g. taus, muon)

Heard informally from jet/etmiss - no pressing need seen so far.
More interesting if it happens e.g. in time for HCP.

No word yet from tile, SM, Exotics, SUSY, Higgs.
 
#####
Summary:

1)ID and tracking interested in fixing the TRT problem ASAP after
ICHEP cutoffs.

"I am not happy leaving it in. we have to understand the back tracking and TRT standalone tracks, this is 
the next in the commissioning of the tracking. we need to get control and performance feedback urgently, especially 
since we will get pileup and we have little performance feedback on back tracking and trt only with pileup."

2)e/gamma interested in implementing a correction for dead OTX
  in back and especially in presampler which currently result in a 1.4% 
  loss in efficiency for W/Z analysis.

  (code is in 15.8, but some constants may need to be added to DB)

  "So such a reprocessing might be desirable for egamma."

3)Not needed for top 
   "unless it becomes clear there are big benefits for the combined performance groups"

4)Not needed for B physics
    unless ID requests it to "dramatically improve tracking performance"
    or "muon combined performance group requests it for low pt muon reconstruction"

5)Muon CP has no requests of their own, but might support requests from the
   muon detectors.

6)"no pressing needs in b-tagging for something like this"

###
Verbatim comments:

I)Laurent for e/gamma

"If there will be a reprocessing with 15.8.X.Y in July (with a change of
T0), egamma would
 therefore benefits from a new calibration scheme which will be able to
deal with the dead OTX in back
 but also especially in Presampler. Today these regions are removed from
the W/Z analysis inducing
  a 1.4 % efficiency loss. Moreover such a fix would be even more
important if we have a new dead
  OTX dead in PS over summer.  So such a reprocessing might be desirable
for egamma."

(this is the L1Calo OTX correction, or is this something else?)

"Yes this a different procedure. When the PS has a dead OTX, we
replace the standard Calib Hit method formula of the barrel
   by a calibration scheme as used in the Endcap where there is no
presampler in order to recover the energy loss in dead
   material. The L1calo-based correction for dead OTX will not be used
for egamma as not enough accurate (even more
   true when the PS is missing as you need to substract for the L1 tower
the signal the larger signal from Stip+Middle+Back
   to have an estimate of the PS energy).
   This procedure, done by D. Banfi and L. Carminati,  is in a cache of
15.8 (still the coefficients needs to go in the database)
 
         Regards, Laurent

   PS : If there is a reprocessing, I guess the dead OTX  list will be
updated with the one we lost 10 days ago ?"

II)Markus for ID
"there is the obvious candidate, which is the TRT tracking bug. We had discussed this in the 2 last 
 Reco meetings, I guess we do not need to do it again, do we ? 
  people are aware that this is a problem that we like to fix as soon as possible (after the ICHEP deadline)."

and later

"For risking that ATLAS misses ICHEP, yes, I was the first to say we should not risk it, as a delay by 
weeks would risk ATLAS results being in time. but to leave it in once we have the opportunity to fix it, 
certainly not. this was a judgement call, not more and not less.

I am not happy leaving it in. we have to understand the back tracking and TRT standalone tracks, this is 
the next in the commissioning of the tracking. we need to get control and performance feedback urgently, especially 
since we will get pileup and we have little performance feedback on back tracking and trt only with pileup."

III)Christian Schmitt for tracking,
"from the tracking performance group we are in the same boat as the ID
with the TRT bug."

"obviously we would like to have it fixed as soon as possible after
ICHEP. Therefore in case there are also other needs (apart from the TRT
bug) and also other groups expressing that an earlier date is preferable
this should be done in a special campaign in my opinion."

IV)Richard for top
"From the top physics group point of view, we see no need for an intermediate summer reprocessing, 
         unless it becomes clear there are big benefits for the combined performance groups."

V)James for b physics
"As far as B-physics is concerned I can see no need for a reprocessing before September, unless 

(a) The inner detector group requests it to dramatically improve tracking performance
(b) The muon combined performance group requests it for low pt muon reconstruction
(c) Something goes terribly wrong in the next big runs (but that applies to everyone I guess....)"

VI)Stefania for muon detectors
"for the muon sw, we'll attach a note to the agenda of teh meeting as you suggested - in general we a 
have a few issues that would be better treated in a reprocessing based on 15.8.0 pcaches."

VII)Domizia for muon CP

"sorry we were iterating with Muon Spectrometer before
answering for Muon Combined Performance since we do not have special
requests yet from the combined side but would have liked to fully
understand the implications of detector changes and reply accordingly
eventually supporting them. Meanwhile for the muon combined reconstruction
we don't have urgent needs."

VIII)Gordon for b tagging
"We sent this around yesterday and I've gotten only one response back which was "over my dead body" in nature. 
At the moment there are no pressing needs in b-tagging for something like this."