sPHENIX discussion of physics

[Anthony Frawley <afrawley AT fsu.edu>]

Hi All,

Here are the minutes of today's topical group meeting. The slides are at:

https://indico.bnl.gov/event/16457/

Tony Frawley - simulations for pp running:

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Proposal for setting time windows for pileup and hit reconstruction in simulations in extended readout pp running.

Jin: Showers in the calorimeters produce free neutrons, can enter the TPC microseconds later. May be good to extend the pileup window for the TPC to earlier than -13.2 μs. Will look into this. The cuts in the HitReco modules are fine.

Yasser: there is a flag in the MVTX macro to set the pileup window/time-cuts based on the strobe length and integration time, would be different for pp than AuAu.

Tony: Plan to have a global level flag in the macro that selects pp or AuAu running, will be used in all subsystem macros to set the pileup windows and time cuts.

Jin: Regarding misidentified hadron background studies using MB Pythia events without eID - the hadron rejection in jets may be topology dependent. So MB Pythia events are not a very realistic background sample.

Tony: Would also not have the correlated background from real physics. This was not intended to be a prediction of the combinatoric background, but a useful sample for tuning track cuts for S/B optimization.

Zhaozhong Shi - EvtGen progress:

---------------------------------------------

Geant 10.07 has disabled the use of a custom decayer (available in 10.06), and replaced it with a single decay channel. Workaround suggested by developers, not tested yet.

Cameron, slide 7: Should we run EvtGen by default, and revert to Pythia if not present? Jin: Better/safer to be explicit about the decayer and quit if it is not present. Agreed.

Jin: The Pythia8 decayer should work, use that as a template for Evtgen for the new Geant version.

Discussion about simulation files - All:

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What existing simulation files to delete? What should we run next?

Cameron: Suggest deleting the Run 4 charm sample - decayer issue makes it garbage. Run 3 bottom has the incorrect pileup issue, can still be used for debugging.

Chris: Can fall back to G4 10.06, will allow decayer to work. What should we run? All agreed that the immediate priority is charm.

Jin: Do we want to wait a few days to test if the Pythia8 decayer works before starting?

Conclusion:

  Delete run4 charm files now.

  Test Pythia8 decayer. Switch back to G4 10.06 if it does not work

  Delete run3 bottom files later when they can be replaced.

---

From: Anthony Frawley <afrawley AT fsu.edu>

Sent: Tuesday, July 12, 2022 5:43 PM
To: sphenix-physics-l AT lists.bnl.gov <sphenix-physics-l AT lists.bnl.gov>; sphenix-hf-l AT lists.bnl.gov <sphenix-hf-l AT lists.bnl.gov>; Sphenix-upsilons-l AT lists.bnl.gov <Sphenix-upsilons-l AT lists.bnl.gov>

Cc: Anthony Frawley <afrawley AT fsu.edu>

Subject: HF/Quarkonium topical group meeting Wednewsday July 13 at 9:30 am EDT

 

Hi All,

We will have our HF/Q topical group meeting tomorrow, Wednesday July 13, at 9:30 am EDT.

Agenda:

  Introduction - conveners

  EvtGen - Zhaozhong Shi

  pp simulations - Tony Frawley

  Discussion of simulation file usage - what can we delete?

The indico page is:

https://indico.bnl.gov/event/16457/

The zoom link is:

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

Cheers

Cameron, Jin, Tony, Marzia