sPHENIX cold QCD topical group

["Aidala, Christine" <caidala AT bnl.gov>]

Minutes from today’s meeting are below.

 

Christine

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Report on BNL retreat on an EIC detector in Building 1008 (sPHENIX hall) - Nils

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Agreement on a number of sPHENIX components that could be reused vs. not reused.  A number of action items identified—see slides 6-8.  Many will need to be followed up after the LOI.  General interest in creating a sustained effort toward an EIC detector in 1008 beyond the LOI.

 

8:30 pm meeting time cited as barrier to wider participation by individuals at BNL.  Will look for a new meeting time, or possibly alternating times, to accommodate all interested in participating.  Christine and Nils will send out poll.

 

 

Other news

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National Academy of Sciences study assessing the science case for an EIC will be released tomorrow (7/24) at 1:00 pm EDT, in conjunction with a live webinar.  Pre-registration for the webinar required (free).  For more information, see http://eicollider.eventbrite.com.

 

 

Effect of changing vertex position on EIC-sPHENIX – Athira KV

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Studied effect of changing collision vertex position on pseudorapidity coverage, fraction of events with scattered electron detected in (high-resolution) EEMC, min and max x values accessible via electron measurement in EEMC.  Looked at 18 x 275 GeV and 5 x 100 GeV.

 

Position and size of EEMC fixed in the study (Scenarios 1-4, and Scenario 5 without electron-going modular RICH studied).  Suggestion to move back EEMC, and move collision vertex accordingly, to create more space for hadron direction spectrometer.  E.g. move back EEMC a few tens of cm and put collision vertex at z= -50 cm, i.e. 4 m from one end of IR, 5 m from other end, rather than equidistant.  Christine will follow up with IR Group to see if this would be feasible.

 

Conclusions – For fixed EEMC position, varying vertex by up to +-20 cm from z=0 (the center of the IR) does not lead to a significant difference in the fraction of 18 x 275 GeV events with the scattered electron detected in the EEMC, or to an extended x range covered.  This is because with an 18 GeV beam and cut of Q^2 > 1 GeV^2, the minimum eta of -4 for z=0 collisions already comfortably covers the most backward scattered electrons.  More significant difference in fraction of events with scattered electron in EEMC for 5 x 100 GeV as move z vertex.

 

 

EIC Deeply Virtual Meson Production – Gregory Matousek

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Looked at exclusive J/Psi production using Sartre.  Electron-positron decay, putting through GEANT4.  Simple track-cluster matching performed.  Invariant mass resolution on reconstructed J/Psi being studied.  Next step to look into strange features in eta, phi reco vs. truth plots.

 

 

Comparing kinematic reconstruction methods for DIS – Cynthia Nunez

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For neutral current (NC) DIS events, reconstructing kinematics via both scattered electron and Jacquet-Blondel hadronic method to determine relative performance of each in different kinematic regions.  Also looking at JB to see how well can reconstruct charged current (CC) DIS, where no scattered electron is available.  PYTHIA6 settings described in detail on slides.

 

Turning off all initial-state and final-state radiation including bremsstrahlung (which required turning off three separate items in PYTHIA), perfect consistency achieved in Q2, x, and y reconstruction using electron method, JB, and PYTHIA truth -> reconstruction methods well understood.  As next step in greater realism, turned on radiation back on to see effect on reconstruction of kinematics. 

 

Moving forward, will add increasing realism by adding geometrical cuts on detected particles, then momentum and energy smearing, and finally PID efficiency.  Continuous parameterizations of momentum resolution will be available from Stony Brook soon.  For far-forward region (4 < eta < 5) where there’s HCal coverage but no EMCal or tracking, just assume that can effectively measure particles out to eta = 4, with the extended area taking care of edge/leakage effects.  For resolution on angle of scattered electron, Jin suggests to use 1 mrad in azimuthal, 3 mrad in polar angle for now.

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From: EIC-dsg-l <eic-dsg-l-bounces AT lists.bnl.gov> on behalf of Nils Feege <nils.feege AT stonybrook.edu>
Sent: Thursday, July 19, 2018 12:54:31 PM
To: sphenix-cold-qcd-l AT lists.bnl.gov; eic-dsg-l AT lists.bnl.gov
Subject: [EIC-dsg-l] Next EIC Detector Study Group / sPHENIX Cold QCD TG meeting on Monday, July 23rd, evening at 8:30pm ET

 

Dear EIC and Cold QCD enthusiasts,

our next meeting is scheduled for

Monday, July 23rd, 8:30pm ET.

The meeting is BlueJeans only (https://bluejeans.com/345777492) with the agenda evolving at https://indico.bnl.gov/event/4867. Please let us know if you have something to present.

We look forward to hearing you at the meeting.

Best,

Christine Aidala & Nils Feege

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Dr. Nils Feege

Research Assistant Professor

SUNY at Stony Brook

Department of Physics & Astronomy

Stony Brook, NY 11794-3800

e-mail nils.feege AT stonybrook.edu

skype nils1920

phone +1-631-632-8710

www.linkedin.com/in/nilsfeege