sPHENIX is a new detector at RHIC.

[David Morrison <dave AT bnl.gov>]

Dear collaborators,

I appreciate Ron Belmont taking notes at our last fortnightly meeting!  Below is a lightly edited version of those minutes, and the agenda we followed is here: https://indico.bnl.gov/conferenceDisplay.py?confId=2191

Cheers,

Dave

=== DAVE ===

Last meeting preempted by PAC
Submitted response to baseline scope charge on June 6
Thanks to all in collaboration for work that underlies document!

Test beam vetting
TPC tracking for full HIJING
Jet energy response for calorimeter and calo options
Hadron rejection e/pi separation based on emcal options

Organized and done in very short time scale

Acknowledged by ALD – timing of more formal response discussed at ALD/Spokespersons meeting on 7/5.

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Public affairs office--three different news articles!
sphenix as collaboration (https://www.bnl.gov/newsroom/news.php?a=26258)
special story about magnet (https://www.bnl.gov/newsroom/news.php?a=26367)
special story about test beam (https://www.bnl.gov/newsroom/news.php?a=26385)

Helpful timing of the articles

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Users meeting - very good posters and talks
sphenix factored heavily into discussions: physics, timelines, plans, etc

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Tim Hallman's talk includes sphenix in DOE timeline---very encouraging to have names and dates

EO: Additional endorsement of US HI program
DOE OS slide by DOE OS director
JL: Amazing that this shows up with official DOE logo

DM: Plan to show this slide a lot!

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PAC meeting
Important ave by which Berndt gets advice
sphenix commended for progress
Good comments from Krishna and Volker
PAC had positive evaluation of response to charge
The community says the physics we say we will do is important

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Formation of cold QCD topical group
This topical group is broader than the current three
Need a forum and structure for people interested in spin, hadron structure, EIC physics, etc
*** Dave and Gunther are seeking nominations for conveners! ***

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Calendar
S&T review end of August (https://indico.bnl.gov/conferenceDisplay.py?confId=2238)

Review of sphenix tracking options Sept 7-9

=== ED OBRIEN ===

Need to revise cost estimates in advance of Fall C&S review
Active work on vendor quotes
Certify/confirm quotes are valid whenever possible
Value engineering: cost reductions through redesign
Recent successful discussion on redesign of inner hcal
Prep ongoing for Jan 2017 FNAL test
Digitzer will be available for Jan 2017 FNAL beam test
Full scale Mechanical prototypes, will not be tested at FNAL---good check on vendors and construction
OHCal and IHCal definitely, discussion with Anne and Craig for attempting to do this for EMCal

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Near term schedule
EMCal workfest Aug 11-12
DOE S&T late Aug
BNL charged sphenix tracker review early september

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Internal cost and schedule reviews
MAPS June 30 (https://indico.bnl.gov/conferenceDisplay.py?confId=2225)
TPC July 13 or 14 (day will be decided early next week)
Want outsiders on committee for perspective
Review is of both mechanics and electronics

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sphenix future schedule

CD0 in the mid fall
C&S review in the late fall
Do we have reservation at FTBF for Jan 2017?
*** CD1/CD3a in one year from now! ***
*** Preproduction R&D and design complete 2 years from now! ***
*** CD2/CD3b 2 years from now! ***
Need some float in schedule for DOE approval (7-10 months)
Currently have 8.5 months of float (schedule contingency)

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Lots of people contributing

*** need more people TPC electronics ***
*** tracker external support not started yet ***
18 months for full phenix removal

=== DENNIS ===

Jet structure group plans on directing and contributing to sim studies for physics scope of the group for the tracking review
Tend to think of high pT tracking, but low pT tracking potentially very important for certain physics topics
Need to coordinate with Upsilon group since tracking is the key performance issue there
Plan to contine the model for stdized MC sample and detect configs
Planning more discussions and work organization starting next week!
Now biweekly meetings Tues at 11am starting next week June 28

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Most of the past tracking configurations no longer planning to be used

DM: Javier had looked into performance of particle flow algorithms for jet finding. Modest effect found.
DP: Agree
DM: Recheck with different tracking options
DP: Agree.  Some interest in the group in renewing that effort.  First step is to remind ourselves of Javier's already substantial work

=== MARZIA ===

Goal: Y(1S), Y(2S), Y(3S) RAA
Performance plots oriented towards 0-10% AuAu, most challenning
Mass resolution to separate states depends on momentum resolution
Track eff
PID eff
Combinatorial background (depends on PID purity)

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Intermediate tracker a big issue: pattern recognition and momentum resolution

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BG issues mostly to do with PID

DM: Clustering hasn't gotten a whole lot of attention yet?
MR: Yes, issues is how to cluster in 100% occupancy environment.  Jin's idea: clusterize around a track.  Need some kind of cluster fitting to separate physics clusters from bg clusters.  Low pT is the biggest challenge.

DP: Gunther's student Brandon will look at clustering photons and electrons in AuAu, he should contact you and Tony to fit in to topical group?
MR: Yes!  Definitely need more people.  Want two different clustering algorithms, photons and electrons, especially if do 2x2 ganging.

DM: All being organized in topical groups?
MR: Major revolution in tracking, so we're not pushing too much.  Will go to biweekly meeting in mid July when tracking settles down.

=== YASUYUKI ===

Idea: 1 pixel layer, 4 strip layers, EMC hit (outer tracker)
Outer tracker: TPC can work, but drift chamber can also work. 
Miminum model here, can add more strip or pixel layers as needed.

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Gaku made implementation
1 pixel layer, 4 strip layer, outer detector with 6 layers (implemented as strip)
minimum model has sufficient performance to clearly separate the three ups states

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Very clear separation in p+p
Very good 1s 2s sep in hijing, 2s 3s sep not so good
Part of problem is limitation of reconstruction code, can be improved.

TF: 110 Mev is not okay.  Fine to say you can improve reco code, but must demonstrate.
Have no experience with this.  Qualitative statements have no meaning.

MM: Some confusion in hijing that can be fixed with algorithm, some confusion in hijing that's intrinstic to design.
Going from 12mm six layer silicon to DC could have huge effect on confusion, needs careful study.

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TF: What limitation for 12 mm?
YA: Takes too long
MM: Long time due to high fake rate

MM: Try peripheral or mid central, wouldn't take nearly as much time, then you could convince us that the issue is memory.

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Outer tracker concept: like the x1 section of phenix DC

EO: Drift cell is both sides?
YA: Yes, both sides.
4cm max drift length means 64 of these for 2pi coverage
Need 768 total wires, 1536 read out channels, 1/8 phenix DC
Read out with 8bit ADC
4 sampling enables shaping, should get 1mm 1 track resolution.
Current phenix is 1.5mm

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Track density 1/cm in central AuAu
Need to demonstrate reconstruction of tracks in central AuAu

EO: I'll write something up and send it to you about this (https://lists.bnl.gov/pipermail/sphenix-tracking-l/2016-July/000292.html)
EO: This DC design would have 8 times the number of tracks per wire.

=== TAKAO ===

TPC electronics
40 GB/s, holy data batman! [sic]
Need to consider data volume reduction

MM: Continuous readout?
TS: Yes
MM: 15kHz, interaction rate or trigger rate?
TS: Trigger rate from DAQ.  CAD thinks they can provide 25kHz interaction.
MM: Assume luminosity leveling at 30kHz?
TS: Yes

DM: Need a follow up with CAD and Wolfram about what conditions we might be looking at. Can introduce crossing angle, thereby reducing fraction of events outside of certain vertex region.
DM: Some discussion about getting in touch with ALICE folks abuot DAQ, readout, handling, etc. for their upgrade plans.  We should be planning for the discussion to really understand what is involved and what one needs to do to handle that kind of readout system.

=== MIKE ===

MAPS HAT:
Obtained pad model from ALICE for inner barrel tracker
Tracking review: really focused on C&S and resource items

TRACKING HAT:
Really concerned about pileup and how many MAPS layers we might need,
or intermediate layer

HEAVY FLAVOR HAT:
Will have a discussion biweekly meetings
Bottom jet ID, purity, efficiency---continuing to push for design options
No meeting until Jin returns

TPC HAT:
Some organization there as well

David Morrison Brookhaven National Laboratory phone: 631-344-5840
Physics Department, Bldg 510 C email: dave AT bnl.gov
Upton, NY 11973-5000

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