sPHENIX is a new detector at RHIC.

[David Morrison <morrison AT bnl.gov>]

Dear collaborators,

Notes from the last general meeting.  Thanks Rachid!  Today's meeting
starts in a few minutes.

Dave

-------- Forwarded Message --------
Subject: Notes from the 35th sPHENIX General meeting: October 06, 2017
Date: Sun, 8 Oct 2017 21:39:47 -0400
From: nouicer <rachid.nouicer AT bnl.gov>
To: David Morrison <dave AT bnl.gov>, Gunther Roland <rolandg AT mit.edu>

Dear Dave and Gunther,

My notes that I took during the meeting are below.

Sincerely,
Rachid

----------------------------------------------------------------------------------------

Notes from the 35th sPHENIX General meeting:  October 06, 2017

https://indico.bnl.gov/conferenceDisplay.py?confId=3701


------------
1) sPHENIX collaboration news:
Speakers: Dr. David Morrison (BNL), Prof. Gunther Roland (MIT)

- Medium energy physics:

      . Document of medium energy was sent to ALD Berndt.
      . Berndt sent us back his comments and suggestions, but some of
them were vague.
      . Berndt's comments/suggestions were sent to the authors of the
document.
      . Berndt's suggested to add an executive summary to the medium
energy document
        and this will help DOE to carry the message better.

Q: Could you send Berndt's comments to sPHENIX?
A (Dave): yes, I will do it after the meeting.

Q: When Berndt will have meeting with DOE about sPHENIX and Medium
energy documents?
A (Dave): Berndt says:

           - he plans to meet with DOE on the issue of medium energy
funding next week
       - sPHENIX: early November

- Magnet status:

          . there is a lot of progress, but PHENIX is straggling to get
resources to achieve magnet test.
          . Berndt asked sPHENIX to express these concerns of magnet
tests in a written document.
          . spHENIX will make written document about magnet test challenges.


     * During DOE visit this week, the ALD Berndt confirmed to DOE the
high priority of the sPHENIX for BNL lab.

- EIC related news

          . Abhay Deshpande is the Director of Science for the Electron
Ion Collider (EIC), at BNL.
          . Temple meeting November 30-December 1, 2017.
          . We will have an ePHENIX talk at the Temple meeting.
          . It is important to show to the world that sPHENIX is the
base for a detector at EIC.

     * We have a good representation of sPHENIX members in the Bi-weekly
eRHIC coffee klatsch at BNL.
       However, if sPHENIX people are at BNL, that will be great if they
come to the eRHIC coffee klatsch,
       more people from our collaboration at that event it is always
better for us/spHENIX.


- Collaboration meeting

           . December 8-10 in Santa Fe, to be preceded by MVTX workfest.
           . Nominal registration fee for the meeting ~$100

- Applying to be CERN recognized experiment

           . This document will make sPHENIX in an official position as
an experiment from point of view of CERN.
           . Several advantages if this is successful. Able to talk with
CERN about sPHENIX on an official basis
            such as about assembling/specific expectations regarding
CERN : GEM, MAPS facilities

- Descoping strategy:

           . Berndt will meet with DOE to discuss Calorimeter/PHENIX
descoping in early of November.
           . Co-spokespersons would coordinate drafting of document for
Berndt ALD.


------------
2) sPHENIX Project Update 20'
Speaker: Edward O'Brien (BNL)


- sPHENIX Project Update:

           . Beam test preparations are making good progress.
           . We are made a lot of progress in closing the 33 action
items from the Director’s review.
           . We are identifying additional personnel for the project team.
           . INTT will part of the beam test.
           . BNL/RBRC hired a new engineer, Dan CACACE, which will be
working on INTT and Calorimeter.

- sPHENIX Management Issues II:

          . The scrubbing exercise identified ~$100k in savings from
re-examining the sPHENIX cost estimate.
          . Other $700k engineering materials saving from other
sub-detectors.

- Proposed review dates for Conceptual Design Reviews

           .  Nov 1 HCAL
           .  Nov 8 EMCAL
           .  Nov 15 Cal Electronics
           .  Nov 29 TPC+TPC electronics
           .  Dec 13 DAQ/Trigger+MBD
           . January 5, 2018 is target date for completion of CDR

- sPHENIX Management Issues II:

           . We need Project Manager: Designate a person in charge of
all Budget and Schedule
             aspects of the MIE + Infrastructure and Facility Upgrade

Q (Dave): Many tasks but the overall status?

A (Ed): yes many tasks but most important are on the slide #3. Berndt
and us are working hard on these tasks.

Dave/Ed: DOE seems working with sPHENIX and helping some funding available.

------------
3) T-1044 2017 EMCal Note
Joe Osborn for the EMCal group


           . Analysis of 2017 EMCal test beam data has been posted
           . First 2D projective SPACAL EMCal
           . plan for beam energy scan: Two data sets and Two energy
recalibration methods
           . Hodoscope correction was used and published in 2016 test
beam paper

- New Method: Position Recalibration

            . 2017 test beam introduces new cluster position dependent
correction

- Energy Recalibration

            . Hodoscope and position dependent recalibrations yield
similar improvements to resolution

Final Resolution

            . Simulation matches data

-What Have We Learned?

            . Intrinsic resolution of the 2D projective SPACAL tower.
            . Cluster position energy correction works as well as
hodoscope position energy correction.
            . Towers are accurately described in simulation.

Conclusions:

            . First public showing of 2017 test beam results to be shown
at IEEE talk on October 26th


Q (Dave): quite good progress. Do you expect that energy cluster
position will work for AuAu?
A (Joe): we don't know. It is on our to-do list.

Q (Dave): the 2D projective: does help to fix the cracks in the acceptance?
A (Woody): the modules' reposition to 150 mrad in phi and in eta 15 cm
make the geometry complicated but better coverage.


------------
T-1044 2017 HCal note
Ron Belmont for the HCal Group

             . Data: energy resolution is better than sPHENIX
specifications.
             . Energy linearity is excellent.
             . Simulation and data have a good agreement.
             . Distributions of pions: data and simulation have a good
agreement.
             . HCal + EMCAL: you get the best energy resolution.
             . HCal works, with excellent linearity and better than spec
resolution.

- conclusion:

            . 2017 beam test HCal note ready to circulate.
            . 2018 beam test data will yield critical insights about
inner HCal de-scoping.
            . Megan will show all the 2017 beam test results at the IEEE
meeting.


Comment (Ed): I don't expect that forward Cal. and middle Cal behave
exactly the same.

Q (Peter) on slide #5: Small peak at low energy ?
                       What is this?

A (Ron): it is due to muons punch through (muons from contamination)

Q (Peter): could you remove it by just using a cut?
A (John Lajoie): it should not affect the variant of the full peak.

                    Ron:  HCal note will be circulated in a coming week.

------------
Further Jets Studies for the IHCAL
Rosi Reed for the iHCal Group

           . simulation has been updated with the de-scoping and we are
looking to the results.
           . Do the configurations (de-scoping options) increase the
bias with respect to fragmentation?
             such as in 1) Quark vs Gluon jets, 2) High    z jets
           . Conditons:
                 - SS310, SS310 w/o readout, Al, and Al w/o readout, and
SS310 frame (steel cylinder)
                 - “Matched” jets require track and tower jets match the
primary jet within ΔR<0.4

           . HCAL correction:
                  - Consistent with test beam results
                   - Constant as a function of energy

Q (Jamie) comments: scale factors change a lot because of material
changes (Stainless steel)
A (Rosi): there is a lot work need to be done and steel is extrem choice

- After Tower Corrections, I and II

Q (Jamie): you said performances are the same?
A (Rosi):  these corrections do not affect the decision that we are making


- Jets energy scale and Jet energy resolution

             . Jet energy resolution is getting worse with Stainless
steel choice.

Question with echo: changing geomtery is affecting energy resolution and
this is very bad?

A (Rosi):  yes the energy resolution is getting bad but we need more
information on how to do configuration


- Combined Jets    JES and JER:

               . Energy resolution is not so bad if we use propre algorithm

Q: these numbers on the table are idealised?

A (Rosi): we are trying to span several different scenario as function
of time and resources. We are making sure that decision are not made
on worse or best case. We will continue working on this in the next
two weeks.

Lajoie: it is clear that people are wory of making decision based on
    these simulations. We need to use particle flow algorithm and
    maybe we need to use tracker.

Jamie: it is important to have a unique match between the tracking and
Calorimter energy.

Gunther: particle flow algorithm works very nicely in CMS.

Rose: we need to give feedback to Berndt in a couple of week.


- Flavor Jet Studies:

             . more study will be done later but this is the first look
about quarks versus gluons

Q (Aroan, from Nevis): I don't understand why we are doing this ?
                                     Are we going to do separation
between quarks and gluons?

A (Rosi): we are doing this study to make sure that our configuration
doesn't make this study harder in the future.

John Lajoie: I would lkie to point out that monte carlo has been changed
since our last meeting.


------------
Inner HCAL Design and Descoping Options
J. Lajoie

            . To make inner HCAL cheaper with new configuration, we save
$420k.
            . Aluminum is more suitable, and this is good for our budget.
            . Many venders are walling to do the work for us because of
using aluminum.
            . Materials' costs for an Al IHCAL could be reduced by as
much as 80%

Q (Dave): you mentioned that the structure holding the inner HCAL made
                from stainless steel may be other material is better?

A (John L.): engineers are suggesting alumiunm but maybe other material,
but the choice is dedicated  by the design.

            . Engineers resources are tight,  and we have to make best
choices.

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-- 
David Morrison  Brookhaven National Laboratory  phone: 631-344-5840
                Physics Department, Bldg 510 C    fax: 631-344-3253
                          Upton, NY 11973-5000  email: dave AT bnl.gov