sPHENIX cold QCD topical group

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

Minutes:

 

Forward EMCal Idea: R&D Progress – John Lajoie

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Prototype development at ISU and cosmic tests described.  Have already cut some E864 towers into 16 cm lengths, corresponding to ~20 radiation lengths.  Get high granularity by introducing arrays of light guides roughly matched to 2-cm Moliere radius. 

 

Each E864 module a 47 x 47 array of fibers.  Can’t get uniform array of same-size light guides.  An irregular 5x5 array of light guides has been designed, each light guide going to a 2x2 array of SiPMs.

 

Cosmic data shown on p. 5-6 taken over ~10 hours.

 

Refinements – will install polished aluminum mirrors on front face—expect ~50% increase in light yield.  Will also use optical RTV to couple SiPMs to light guides.  Goal to use cosmics to get photoelectrons/GeV in the next ~month.

 

Quarkonia with sPHENIX forward EMCal – Sasha Bazilevsky

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Given high granularity proposed, can look at quarkonium -> e+e- capabilities without forward tracking.  tudying J/Psi and upsilon reconstruction in 200 GeV p+p when both tracks are in central barrel, both forward, or one central – one forward.  Used sigma_E/E = 15%/sqrt(E) + 5%. 

 

p. 11 – Full PYTHIA8 events, only look at what goes in the forward region.  No pT cuts shown here, effectively a MB sample.

 

p. 12 – Cluster pT > 2 GeV improves S/B ~ 1/1, with ~2% efficiency for J/Psi, 100% efficiency for upsilon states.  Cluster pT shown in plot.  Page 13 instead is vs. quarkonium pT.

 

Summary – Looks promising for reconstructing J/Psi with forward EMCal alone, upsilon more challenging.

 

Test Beam Experiment for Calorimeters at FNAL – Genki Nukazuka

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4-120 GeV hadron/electron beam.  EMCal + HCal tested, with different lengths of steel inserted in between to check effect on HCal energy resolution.  Good linearity with beam energy observed.  Clear deterioration of energy resolution seen with 10 cm steel wall.  Still analyzing data taken with 1.5 cm steel wall. 

 

Should consider observables that illustrate physics impact of different energy resolutions. 

 

sPHENIX Cold QCD slides for 2019 PAC meeting – Sasha and Christine

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Ended up showing these slides at the May 31 sPHENIX General Meeting at the request of Dave + Gunther—had originally planned to discuss them first here in the TG meeting.  We’re proposing for Dave and Gunther to include these three slides in their PAC talk. 

 

New from the last few months are statistical projections for hadronization in midrapidity b-tagged jets as a function of fragmentation momentum fraction z—studies done by Joe Osborn.  Also new is the impact plot on the gluon distribution in nuclei for sPHENIX central barrel measurements as well as central + forward, by EPPS + John Lajoie + Joe Osborn—arXiv:0904.09921.

 

p. 3 – Point out to Dave + Gunther in e-mail that Drell-Yan constrains gluons indirectly, while direct photons can constrain gluons more directly.  Also try to get better resolution image.

 

Page 4 – Add “in collaboration with STAR” to the HCal bullet point.

 

 

 

 

From: sPHENIX-cold-QCD-l <sphenix-cold-qcd-l-bounces AT lists.bnl.gov> On Behalf Of Aidala, Christine
Sent: Sunday, June 2, 2019 10:33 PM
To: sphenix-cold-qcd-l AT lists.bnl.gov
Subject: Re: [Sphenix-cold-qcd-l] Cold QCD TG meeting Mon, June 3 evening at 8:30 pm ET

 

Dear all,

 

This is just a reminder of our meeting tomorrow, June 3^rd at 8:30 pm EDT.

 

Christine

 

From: Aidala, Christine
Sent: Thursday, May 23, 2019 11:14 AM
To: sphenix-cold-qcd-l AT lists.bnl.gov
Subject: Cold QCD TG meeting Mon, June 3 evening at 8:30 pm ET

 

Dear cold QCD enthusiasts,

 

We will have a meeting on Monday, June 3, at 8:30 pm EDT.  We have three presentations on the agenda, https://indico.bnl.gov/event/6217/.

 

-Progress with E864-based forward EMCal for sPHENIX – John Lajoie

-Possibility for quarkonia measurements with forward EMCal – Sasha Bazilevsky

-Proposed slides as input for PAC talk – Sasha Bazilevsky and Christine Aidala

 

The Bluejeans connection is: https://bluejeans.com/345777492

 

Talk to you then,

Christine and Sasha

 

--

Christine A. Aidala

Associate Professor

Department of Physics

University of Michigan

(734) 764-7611