sPHENIX discussion of physics

[Cameron Thomas Dean <cameron.dean AT cern.ch>]

Hi all,

Here are the minutes from yesterdays meeting:

Reese - D0/D0bar analysis

 

Tony - On the angular correlation spectrum. The files used are the D02Kpi@10GeV jet sample which means these are very high pT D0's. Is the near side peak really due to gluon splitting or gluon splitting and some other process. Does KFParticle give us this information?

Cameron - There is a truth history branch in the nTuple but I would need to check whether I allowed it to record right down to the gluon level or if I stopped it at the quark level.

          UPDATE: Yes, the tracing stops when it sees a photon or gluon so this isn't in the record

Jin - Related, as the sample if coming from the D2Kpi@10GeV sample, I think we limited the production to gg2ccbar and qq2ccbar.

Tony - It wasn't clear to me from the pythia manual if this flag also includes gluon splitting. If I look at D0 production from R_AA measurements, D0/D0bar should not be a statistically limited sample. The double production should be around 4% and Reese has measured it to be about 3% here.

 

Xuan - If we are looking at correlations, Antonio, Jakub and I are thinking of looking at dihadron jet production

Jin - In the 2017 HF note there is a dijet study.

                  For Reese, we also have an inclusive charm sample which has all charm decays and will give a better understanding of the real signal production.

Cameron - Im not sure if these samples were reprocessed but we should check. If we're looking at inclusive charm, I can discuss some ideas on tagging from particle physics experiments

Jakub - I can also update my jet tagger to help do the ccbar tagging

Tony - Where is this tagger?

Jakub - The latest version is local as it was developed for QM but I can push the changes.

 

Antonio - HF jets for run 24

 

Grazyna - You mention you only used calorimeters here. What about using the TPC?

Antonio - We could but at the beginning there will be a lot of calibration on the TPC so we could start looking at the data before the TPC is physics ready.

Tony - The TPC had readout issues in run 2023 that weren't resolved. There is an expectation that this will be ready for the next run as TPC people are working in 1008 now. There will still be calibrations to understand when we see collisions again.

Grazyna - So there's not really data ready

Jin - It will take a while to learn how to bring the TPC to a ready state for physics.

 

Jin - We have a lepton tagger for jets. If we can tag, it has a very high purity but we're limited to about 10% efficiency. Although it doesn't use the trackers, it requires a good E/p value so we need good momentum measurements from the TPC

Marzia - I disagree that you need the TPC. Sasha has shown that you get a good rejection using the EMCal and HCal.

 

Tony - You're looking at semileptonic, what is your charm/bottom separation?

Antonio - This is inclusive right now, I haven't looked at the separation yet.

 

Xuan - We know that for semileptonic decays, there are two dominant background contributions, K+ and photon conversion. Did you consider these?

Antonio - There is some work to be done (I think from ALICE) where you can treat the photon conversion contribution from an invariant mass analysis

Xuan - The light-hadron is a non-negligible contribution. Since you look at semi-leptonics, can you look at D0->mu?

Marzia - How would you find the muon?

Jin - The muon does leave deposits but it's challenging to distinguish from the hadronic shower.

Marzia - If we only use calorimeters, do we get a better sample as calo-only jets are a factor of 10 higher using the jet trigger.

(This should be followed up with Dennis who produced the BUP where these numbers come from)

 

Tony - Where is the "9 week" study from?

Antonio - It reflects the A & B scenarios from the BUP

 

Panel discussion on run 2024 preparedness

 

(Note, the discssion moved too fast for detailed minutes, given here is a summary).

 

In general, there are 5 places where we can prepare for next years run

 

1. The conveners will put together instructions for a min-bias sample with mis-aligned detectors. All analysts should look at the sample and understand the expected resolutions

2. Analysts should try and degrade resolutions so see what momentum and DCA resolution is required to perform their analysis (tied to point 1)

3. We should investigate the E/p resolution with the calorimeters

4. We should look into dE/dx for proton tagging with the TPC. The resolution will be poorer for Kaon/pion separation and may not be achievable but test beam showed a resolution of < 10% (STAR sees about 7% for comparison) and could help recover the low pT protons which will be useful for Lc2pKpi

5. We should look at the K_s0 reconstruction in the TPC sample that was taken this year (Zhaozhong and Reese were asked to look into this when the tracking sample is ready)

 

From: "Dean, Cameron" <cdean AT bnl.gov>
Date: Wednesday, September 20, 2023 at 7:02 AM
To: Cameron Thomas Dean via sPHENIX-l <sphenix-l AT lists.bnl.gov>
Cc: "sphenix-physics-l AT lists.bnl.gov" <sphenix-physics-l AT lists.bnl.gov>, "Liu, Ming Xiong via sPHENIX-HF-jets-l" <sphenix-hf-jets-l AT lists.bnl.gov>
Subject: Re: Next quarkonia and heavy flavor meeting

 

Dear all, 

 

This is a reminder that we will meet today at 1:30 pm ET.

 

Talk to everyone soon,

Tony, Cameron, Jin and Marzia

On Sep 18, 2023, at 10:19 PM, Dean, Cameron <cdean AT bnl.gov> wrote:

 

Dear all,

 

We will have our next joint heavy flavor and quarkonia meeting on Wednesday, September 20th at a new time of 1:30pm ET. Thank you to everyone that filled out the poll for the new semester.

 

The current agenda is

 

• Introduction - Conveners
• D0/D0bar correlations - Reese Boucher, FSU
• Preparations for Run-24 - Conveners

 

For this meeting, the conveners would like to host a panel discussion on what we need to do in preparation for run 2024. Specifically we would like to talk about what tools we need to prepare or update so we can validate the data soon after it is taken. We would like to encourage junior members of the collaboration to participate in the discussion to let us know where they would like to contribute or for us to help get them involved in a project if they are looking for one. We would like to stress that this discussion is aimed at physics preparation for heavy flavor and quarkonia measurements.

 

The indico agenda can be found at https://indico.bnl.gov/event/20608/

And the zoom link is https://bnl.zoomgov.com/j/1613938007?pwd=QjYzUnpYQ2xNZWZLSy9qd3Z4dFpzZz09

 

We look forward to talking to everyone on Wednesday,

Tony, Cameron, Jin and Marzia