sPHENIX cold QCD topical group

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

Here are brief minutes from today’s meeting:

 

John Lajoie – sPHENIX Forward EMC R&D Update

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Further progress reported on reusing cut modules from the E864 HCal to build a forward EMCal.  After Lehigh meeting, remainder of cut E864 calorimeter block shipped from SBU to ISU.  Recent work focused on light guide design—to minimize non-uniformities between towers and reduce cost.  Octagonal light guide design found to collect more light (more bounces) but led to greater non-uniformities.  Plan to have NN, Inc. make multiple versions of light guides using injection molding, with goal of bringing prototype to sPHENIX test beam at Fermilab in spring.  Tentatively plan to submit NSF MRI proposal at end of 2020.  Schedule would be tight, but not impossible.  John will be free of teaching responsibilities next semester in order to devote more time to test beam and other activities to move this forward.

 

Event plane finder development for sPHENIX – Could be possible to use fEMC as an event plane detector.  First version of EpFinder now in github, based on STAR EPD code, and flowAfterburner eta dependence retuned based on PHOBOS data.  Available for use by others.  Further studies ongoing. 

 

 

Sasha Bazilevsky – Direct photons with sPHENIX forward EMCal: Simulation studies

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Now full G4 simulation of full PYTHIA events within Fun4All

 

“Direct” photons in PYTHIA – photons with a photon as parent.  “Fragmentation” photons in PYTHIA – photons with a quark as a parent.  Previous PHENIX MPC-EX studies found that fragmentation photons in PYTHIA overestimated by factor of ~2 compared to calculations by Werner Vogelsang.  In terms of physics probed, may be reasonable to combine direct and fragmentation photons without trying to discriminate them.

 

Efficiency defined here as comparison of all _clusters_ initiated by direct photons versus all _clusters_ that pass cuts.  Additional loss of direct photons before clustering, e.g. due to conversions, investigated and found <2% effect.

 

Overall, looks promising to measure direct photons for pT > ~3 GeV/c:  S/(S+B) = 30-60%.  Charged hadron contribution is small—tracking would not be expected to help much.  Effect of event environment and background due to material is minor.

 

 

--

Christine A. Aidala

Associate Professor

Department of Physics, University of Michigan

Fulbright U.S. Scholar 2019-20, University of Pavia, Italy

 

 

 

 

From: sPHENIX-cold-QCD-l <sphenix-cold-qcd-l-bounces AT lists.bnl.gov> On Behalf Of Alexander Bazilevsky
Sent: Monday, November 11, 2019 7:17 PM
To: sphenix-cold-qcd-l AT lists.bnl.gov
Subject: Re: [Sphenix-cold-qcd-l] Cold QCD TG meeting on Nov 12 9am

 

Dear All,

This is a reminder we meet tomorrow at 9am.

See/hear you tomorrow.

Sasha.

On 11/5/19 9:21 AM, Bazilevsky, Alexander wrote:

Dear Cold QCD-ers,

We plan Cold QCD TG meeting next Tuesday, Nov 12 from 9am (BNL time): https://indico.bnl.gov/event/7047/ with BlueJeans: https://bluejeans.com/345777492

At the moment we plan two presentations:
1. Forward EMCal R&D progress by John L.
2. Direct photon simulation for forward EMCal by Sasha B.

Please let us know if you want to present/discuss anything else.

Christine and Sasha.

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Alexander Bazilevsky

Brookhaven National Laboratory, Bldg. 510D, 2-232

Upton, NY 11973 Tel: 631-344-3712

Email: shura AT bnl.gov

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-- 

Alexander Bazilevsky

Brookhaven National Laboratory, Bldg. 510D, 2-232

Upton, NY 11973 Tel: 631-344-3712

Email: shura AT bnl.gov

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