sPHENIX discussion of physics

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

Announcement:

• Please join the day-1 physics discussion on Friday: https://indico.bnl.gov/event/16728/ 
• We will poll for the best time for the new semester for this joint-TG meeting: https://doodle.com/meeting/participate/id/bkZ5PGKa

 

Brainstorm on calibration needs for first HF/Q measurements 

 

Tony: What level of calibration do we need for each measurement? Some calibrations may take longer than others.  

Joe/Tony: to study the calibration dependency, we can implement fast smearing to mimic effects. A more precise description for the tracker is de-alignment

Jin: simulating de-alignment will be useful for HF, e.g. D0 inv mass for background rejection, which focuses on the resolution for the low pT tracking 

Dennis: Will that be implemented as stochastic shifts? or introducing rotation/shifts errors 

Tony: second case. Distortion is something else for TPC, to be discussed see Ross talk on Friday

 

Jin: from the HF measurements [ https://docs.google.com/presentation/d/e/2PACX-1vQIH_aR5BpeU8TuuLCpOaHXJVjb_QqDmJgN07sA9SHclc2l9js--OsFPh_-cbZZ7VwldHWsJzxkbGQ6/pub?start=false&loop=false&delayms=3000 ], exclusive decay rely less on perfect TPC distortion correction, but we will need good MVTX alignment for background rejection and lineshape for b-c separation. For HF jet, we also need good knowledge for tracking efficiency for efficiency-purity calculation. 

 

 

Tracking in jets: Dan Lis

 

Dan: observed weird low efficiency in phi and eta dependency

Ming: pT>0.8 GeV/c, good to have broad pT regions. 

Anders: pi periodicity in the phi distribution is suspicious

Tony: part of the problem may be from vertex reco&association requirements. 

Joe: high stat. and good to try multi-dimensional binning

Tony: would the requirement on three MVTX hits and the 10-cm vertex lead to some acceptance bias? 

 

Jin: Dip in eta=0 is very curious and not seen in standard jet and few particle QAs:

https://nbviewer.org/github/sPHENIX-Collaboration/QA-gallery/blob/jenkins-sPHENIX-test-tracking-pythiajet-qa-735-test-tracking_Event600_Sum10/QA-tracking.ipynb 

Jin: and good to check the eta and phi distribution in a few pT regions. 

 

 

Electron id update: Weihu Ma

 

Dennis: why negatively charged particles are weaker? 

Weihu/Marzia: pi-:k-:anti-proton ratio is 1:1:1

Jin: difference can come from the initial hadronic interaction and anti-proton is very difficult to reject. 

Conclusion: please separate hadron species (Weihu has the plot)

 

Jin: need more stat. and it is also plausible to do so on SDCC for single particle simulations. 

 

Dennis: please train vs pT to avoid kinematics bias in BDT

 

Weihu: embedding into 0-20fm collisions. 

Jin: will be useful for separated centrality 

 

Sasha: having about 1k Upsilon to HIJING embedding

 

Jin: good to have in the form of an sPHENIX analysis note so can be shown externally. 

 

 

D-D correlation: Xiaozhou Yu

 

Jin: Good to revive the fast sim machinery as moving to a new channel. 

 

Tony: what is the difference between DCA1 and 2?

 

Jin: follow up to obtain the newest performance from recent productions including pile-ups. 

 

 

Quarkonium simulations: Anders Knospe

 

Anders/Sasha: these are upsilons embedded to MB AuAu.

 

Jin: Does \delta R has a large dependency on pT? 

Andres: to be looked at.

 

Joe: What cuts were placed on the track? 

Anders: minimal cuts. Plan to apply more realistic cuts

 

Jin: please use rapidity instead of pseudorapidity for Upsilon as rapidity is more closely related to calculations and decay-daughter acceptance. 

 

Joe/Tony: we have a Gaussian Sum Filter (GSF) for electron analysis! Will follow up with examples of using it

 

 

(verbal) EvtGen decayer: Zhaozhong

 

Validated with particle gun. Pull request ongoing with coding issues. The calibration repo is to be updated with a newer version of the decay table. 

 

 

 

______________________________

 

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-physics-l <sphenix-physics-l-bounces AT lists.bnl.gov> On Behalf Of Huang, Jin
Sent: Tuesday, August 23, 2022 12:14 PM
To: Sphenix-upsilons-l AT lists.bnl.gov; sphenix-hf-Jets-l AT lists.bnl.gov
Cc: sphenix-physics-l AT lists.bnl.gov; malong <malong AT fudan.edu.cn>; Weihu Ma <maweihu AT fudan.edu.cn>; Anders Knospe <ank220 AT lehigh.edu>; Daniel Lis <Daniel.Lis AT colorado.edu>
Subject: [Sphenix-physics-l] [reminder] Joint HF/Quarkonium TG meeting Aug 24 at 9:30AM ET

 

Dear sPHHENIX friends,

 

Our joint HF/Quarkonium TG meeting will be tomorrow at 9:30AM ET. 

 

We have the following talks on the agenda:

• Introduction: co-convenors
• Calibration need In preparation for Day-1 Physics in Run23
• Electron id update - Weihu Ma 
• D-meson pair correlation - Long Ma, Xiaozhou Yu
• Quarkonium simulations - Anders Knospe
• Tracking performance in jet – Dan Lis

 

Please join us via:

https://indico.bnl.gov/event/16639/

 

We look forward to meeting you then.

 

Best regards

Cameron, Jin, Tony and Marzia

 

 

 

______________________________

 

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

______________________________