sPHENIX discussion of physics

["Huang, Jin" <jhuang AT bnl.gov>]

Introduction

1. Bugfix in HF production macro, which picked up a jetty Pythia config file followed with HF channel filtering. It is now fixed and rerunning the sample in the production chain: https://github.com/sPHENIX-Collaboration/MDC2/pull/5 
2. Decayer update: we switch to using Geant4 to handle HF particle decay. The current decayer is Pythia6-based. Zhaozhong Shi (LANL) is working on EvtGen based decayer. Therefore, exclusive channel production will be put to later in the production samples, with the current focus on inclusive HF samples and HF jets. 

 

 

D0/D0_bar - Thomas Marshall

Summary: update cut and MVA analysis on D0/D0 bar separation

 

Jin: two comments that the data makes sense

• 40MeV is approximate mass resolution, turns out to be a good exclusive-false-mass cut value
• Low pT statistics is low probably due to 1) this is 10GeV q^hat Pythia D0 jet events, 2) Acceptance efficiency is higher at high pT

 

Jin on TMVA data: 

• The two-inv-mass-cut method is close to BDT 
• MLP is surprisingly high performant which requires deeper checks 

Thomas: recheck the train-test data separation 

Hideki: was the default macro used for TMVA configuration? It by default separate the samples. 

Thomas: Yes. Will upload macro for cross-check

Hideki: what was the stat. used? 

Thomas: 1k event for training, 70k for testing. Probably want to train more statistics

Hideki: 1k training is too low. And various method's ROCs are too different, which require more checking and higher stat. for this low dimension analysis. Nonetheless, good to see it is working with one night of work!

 

 

HF trigger - Ming, Yasser

Summary: MVTX readout timing feature, very useful to ping down details in HF pile up background

 

 

Jin: Signal width affects effective readout window, e.g. 5us Comparator width and 5us strobe window lead to integrating 10us of time and 30 pile-up collisions. 

Jo/Yasser/Ming: Width is amplitude-dependent and approximately 7us in the ALICE test beam 

Tony: pre-after time needs to nail down to some reasonable range. 

Jin/Ming: we have a trick to shink down the effective integration window of MVTX, by comparing hits shared between two neighboring strobe windows at offline processing. 

 

Slide 7: alignment of MVTX strobe frame and INTT hits 

 

Slide 9: ALICE study show the visible fraction of duplicated hits in shorter-strobe window streaming readout mode

 

TODO: follow up technical meeting flushing out MVTX simulation details to reflect streaming data mode 

 

 

 

______________________________

 

Jin HUANG

 

Physicist, Ph.D.

Brookhaven National Laboratory

Physics Department, Bldg 510 C

Upton, NY 11973-5000

 

Office: 631-344-5898

Cell:   757-604-9946

______________________________

 

From: sPHENIX-MAPS-l <sphenix-maps-l-bounces AT lists.bnl.gov> On Behalf Of Hideki Okawa via sPHENIX-MAPS-l
Sent: Tuesday, February 1, 2022 10:19 AM
To: sphenix-hf-jets-l AT lists.bnl.gov; Sphenix-upsilons-l AT lists.bnl.gov
Cc: sphenix-physics-l AT lists.bnl.gov; sphenix-maps-l AT lists.bnl.gov
Subject: [Sphenix-maps-l] [Feb 2 Wed 9:30AM ET] Joint HF/Quarkonium TG meeting

 

Dear all,

 

We will hold this week's meeting for the joint HF/Quarkonium

TG on February 2 (Wed) at 9:30AM ET.

 

We have the following talks on the agenda:

• Introduction & MDC2 updates: co-convenors
• Follow-up on D0/D0bar separation: Thomas Marshall
• HF trigger development: Ming Liu & Yasser Morales

Please join us via:

Indico: https://indico.bnl.gov/event/14499/

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

 

We look forward to meeting you then.

 

Best regards,

Marzia, Tony, Jin & Hideki