sPHENIX discussion of physics

[Anthony Frawley <afrawley AT fsu.edu>]

Here are my notes on Antonio's talk in today's HF/Q meeting.

Tony

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Conveners comments: Jin said that we should be diligently checking new simulation productions as soon as they are available!

Topo clusters in AuAu collisions at 200 GeV  -  Antonio Carlos Oliveira da Silva:

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Dennis on slides 3-4: The quality measure of (jet-energy-resolution)/(jet-energy-scale) is invariant under scale renormalization - good. 

Slide 5: Not surprising that the topo jets and calo jets are very similar, they are both calorimeter data at bottom.

Jin: The energy scale correction depends on whether it is an electromagnetic or hadronic shower.  Energy scale corrections should best be applied separately to the topo clusters before forming the jet energy. Do you have access to the information needed to decide if the cluster is from an EM or hadronic shower? Antonio: will have to look into that.

Slide 6: What is the x axis? E_F is the ratio of (topo cluster energy) to (total jet energy) in the EMCal or HCal.

Dennis: You could define the EM fraction at the truth level. Not surprised that the EMCal part is higher, since hadrons put some energy in the EMCal. But it seems higher than expected.

Slide 8: The HCal merges high pT hadrons - about 2 per topo cluster. Dennis: It would be useful to study the truth-reco multiplicity correspondence.

Summary:

Jin: Are you using retowered (= 4x4 towers treated as 1 tower) EMCal data? Yes - this is needed for tower-by-tower background subtraction to work.

Dennis: Cluster thresholds are centrality dependent, how were these set? By looking at a study of energy fluctuations. Seems well motivated. Expect to have to retune the thresholds for real data, since Hijing events will not be exactly the same.

 

What does adding tracks involve? Not entirely clear. Have to understand how to do the background subtraction. We have the pT of the tracks.

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From: sPHENIX-upsilons-l <sphenix-upsilons-l-bounces AT lists.bnl.gov> on behalf of Anthony Frawley via sPHENIX-upsilons-l <sphenix-upsilons-l AT lists.bnl.gov>
Sent: Tuesday, May 9, 2023 2:16 PM
To: sPHENIX-HF-jets-l <sphenix-hf-jets-l-bounces AT lists.bnl.gov>; Sphenix-upsilons-l AT lists.bnl.gov <Sphenix-upsilons-l AT lists.bnl.gov>; sphenix-physics-l AT lists.bnl.gov <sphenix-physics-l AT lists.bnl.gov>
Subject: [Sphenix-upsilons-l] HF/Q topical group meeting Thursday May 11 at 11:30 am EDT

 

We will have our usual HF/Q topical group meeting this Thursday at 11:30 am EDT. The indico link is:

https://indico.bnl.gov/event/19474/

The zoom link is:

https://bnl.zoomgov.com/j/1613938007?pwd=QjYzUnpYQ2xNZWZLSy9qd3Z4dFpzZz09

Presently, we have on the agenda:

1. Introduction - conveners.
2. Antonio Silva - Jet Topological Clustering.

Best regards

Cameron, Jin, Marzia, Tony