sPHENIX discussion of physics

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

Introduction - Hideki 

 

Half data completed. Please take a look at the MDC1 sample, and discuss your finds at https://chat.sdcc.bnl.gov/sphenix/channels/hf-mdc1 and topical chat channels. 

 

We plan to refresh the b-jet sample in both p+p and Au+Au after MDC1, taking advantage of the MDC1 production setup. This allows us to refresh b-tagging performance and enables the first analysis with Calo jet finding.

 

New volunteers are welcomed to join the b-jet efforts, in particular on the new topics of fake jet study and soft-lepton taggers. 

 

Hideki/Jin: secondary lepton tagger (SLT) tag b-jet by requiring a displayed lepton (e.g. electron) inside the jet. Comparing to other taggers, SLT has low efficiency due to branching fraction but may have a high purity

Sabastian: SLT useful for systematics and data-driven purity study too as it has high purity and low correlation with displayed taggers

 

 

MDC1 status - Cameron 

 

Great progress on charm sample in MDC1, reaching 30M / 50M planned. 

 

Cameron: We project reaching 60TB storage. Stripping calorimeter absorber information in the coming sample to help save some storage space. 

 

Jin: Ghost track due to noises in TPC, 

Cameron: expect a pull request soon to handle it in the KFParticle truth matching

 

Joe will test the vertex finder that readback reconstructed SvtxTracks and make vertex out of them. This would be useful in MDC1 analysis and in b-jet finding where a subset of the track is used in 2ndary vertex finding

 

Cameron also found a rare bug affecting reco tracks used along with

resonant decays. Expecting a fix soon too. 

 

 

MDC1 studies - Sebastian 

 

First look at non-prompt D0 and D+ sample

 

Slide 3: 

Cameron: Chi2/ndof<10 is too loose, suggest tightening

 

Slide 5:

Jin/Cameron: Chi2IP may remove the non-prompt production from b decays. Suggest use the quality of the secondary vertex ( mother_chi2 as suggested offline in https://chat.sdcc.bnl.gov/sphenix/channels/kfparticle

  )

 

Slide 8: 

DCA(Kpi) is the DCA of the mother from the primary vertex. It may also be interesting to look at the decay length

 

Slide 9: 

Jin/Joe: the wrong reconstructed DCA may be due to contamination of TPC-only tracks. Please cut by requiring at least two MVTX cluster in track

 

Cameron: working on getting truth matching with mother

 

 

Verbal updates

 

Dan Lis:

Working with Joe on qualifying the vertex performance. Trouble getting enough condor time

Updates posted offline: https://chat.sdcc.bnl.gov/sphenix/channels/hf-jet-tc-tagger

 

 

Zhaozhong: 

Working addressing suggestions from the last update: 

• Separating B_s and its antiparticle
• Incorporating the tracking eff. in fast sim.
• Addressing n-track multiplicity based on the Phobos data

 

 

 

 

 

______________________________

 

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: Huang, Jin
Sent: Sunday, February 21, 2021 11:37 AM
To: sphenix-hf-jets-l AT lists.bnl.gov
Cc: sphenix-physics-l AT lists.bnl.gov; sphenix-maps-l AT lists.bnl.gov
Subject: [Feb 22 Monday 8PM ET] bi-weekly heavy flavor topical group meeting

 

Hi Everyone,

 

This is a reminder that we will have our next HF topical group meeting on Feb 22 Monday 8PM ET.  

 

On the agenda:

 

• Introduction including review of b-jet tagging status – co-conveners
• MDC1 report by Cameron Dean
• MDC1 study by Sebastian Tapia

 

Please join us via

 

• Indico: https://indico.bnl.gov/event/10855/
• ZOOM connection: https://bnl.zoomgov.com/j/1613938007?pwd=QjYzUnpYQ2xNZWZLSy9qd3Z4dFpzZz09

 

We look forward to talking to you all at the meeting.

 

Best regards,

 

Hideki & Jin

 

 

 

______________________________

 

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

______________________________