sPHENIX is a new detector at RHIC.

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

Minutes also available on agenda: https://indico.bnl.gov/conferenceDisplay.py?confId=1928

 

Software Update

 

• Event display from Sook Hyun Lee:
  Under review: https://github.com/sPHENIX-Collaboration/coresoftware/pull/194
• Temperature correction in the test beam analysis from Martin Purschke
  Offline discussion on the naming convention: https://github.com/sPHENIX-Collaboration/coresoftware/pull/195

 

 

DCA analysis in 3D - Haiwang Yu

 

Summary: Exploring and verifying 2-D/3-D DCA calculation based on the GenFit Kalman filtering package

 

Slide 3: Three 2-DCA determination method are available. Compared with each other show consist result to a very good level (Difference << 1um).

 

Slide 4:

·       Verification of error calculation on 2-D DCA.

·       Mistry that both Kalman filter underestimate error.

·       New GenFit show constant observed DCA width / estimated error VS pT

 

Jin: Could come from cluster error estimation on the MAPS detector is off by a constant factor.  

 

Slide 6: Two 3-D DCA calculation methods also show good consistency (difference << 1um).

Haiwang: Mystery why DCA 3D

Jin: 3-D DCA here is defined as radius of a 2-D Gauss distribution. The phase space grows linearly with respect to radius, what lead to this shape. Suggest quantify the sigmalization quality via 2-D distribution DCA/sigma DCA in both u and v directions.

 

Conclusion: 

·       General suggestion: draw a diagram for the definitions of various DCAs.

·       Storage: plan to store new 3D DCA variables to SvtxTrackv1 object.

·       Plan: cut on DCA3D for track counting b-tagging.

 

 

B-tagging with secondary vertex

 

Summary: first results on secondary vertex pT and mass distribution

 

Slide 3: b-jets show larger multiplicity and higher vertex pT on the secondary vertex

Slide 4:

·       A cut with secondary vertex pT/jet pT > 0.15 produce similar b-tagging performance when compared to a cut of track pT>1.0 GeV/c at b-efficiency<70%. Slightly better performance observed for the region of b-efficiency>70%.

·       Secondary vertex mass show promising discrimination power

 

Suggestion/Plan

·       Blind analysis to estimate b-jet fraction using template likelihood fitting of vertex mass, or vertex mass + vertex pT

·       Embedding into HIJING and establish HIJING performance

·       Upload analysis module to GitHub after clean up.

 

 

 

 

 

 

______________________________

 

Jin HUANG

 

Brookhaven National Laboratory

Physics Department, Bldg 510 C

Upton, NY 11973-5000

 

Office: 631-344-5898

Cell:   757-604-9946

______________________________

 

From: Huang, Jin
Sent: Monday, September 19, 2016 2:17 PM
To: 'sphenix-software-l AT lists.bnl.gov' <sphenix-software-l AT lists.bnl.gov>; 'sphenix-l AT lists.bnl.gov' <sphenix-l AT lists.bnl.gov>
Subject: [reminder] sPHENIX simulation and software meeting, Tue Sept 20th, 1PM EST @ 2-219

 

Hello everyone,

 

This is a reminder for a regular sPHENIX simulation and software meeting, Tue Sept 20th, 1PM EST @ 2-219.

 

Currently on agenda are:

·       3D DCA and using it for b-jet tagging

·       b-tagging with displaced vertex

Please let us know if you have further topics to be presented at this meeting.  

 

The agenda page is at https://indico.bnl.gov/conferenceDisplay.py?confId=1928   , for which the common modification password is "1008"

•            For residents at BNL, we will meet at the 2-219 conference room

•            To join the Meeting via phone bridge:  https://bluejeans.com/619960505 

•            To join via Phone:

1) Dial:

        +1.408.740.7256

        +1.888.240.2560(US Toll Free)

        +1.408.317.9253(Alternate number)

        (see all numbers - http://bluejeans.com/numbers)

2) Enter Conference ID: 619960505

 

Cheers,

 

Jin

 

 

______________________________

 

Jin HUANG

 

Brookhaven National Laboratory

Physics Department, Bldg 510 C

Upton, NY 11973-5000

 

Office: 631-344-5898

Cell:   757-604-9946

______________________________

 

 

 

______________________________

 

Jin HUANG

 

Brookhaven National Laboratory

Physics Department, Bldg 510 C

Upton, NY 11973-5000

 

Office: 631-344-5898

Cell:   757-604-9946

______________________________