sPHENIX is a new detector at RHIC.

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

Short meeting today. Minutes as following:

 

 

DCA reconstruction quality check - Haiwang Yu

 

Slide2: The problem - pull distribution in DCA fit report too large error which induce a narrow pull distribution

 

Slide 4: Check uncertainty reported by MAPS clusters in the cylindrical model.

 

Haiwang: the RMS reported is larger than 20um cell size /sqrt(12)

Jin: could be affect significantly by the grass in the long tail

 

Haiwang: not sure why the z pull distribution do not show a squire distribution

Dave/John/Jin: expect to relate to the polar angle of the track which could distribute charge into multiple cells

 

Slide 6: checked pull distribution of DCA by trying using RMS cluster error as position uncertainty  of cluster.

 

Jin: suggest chase down the source of difference by 1) turn off multiple scattering 2) turn off vertex error by using truth vertex, 3) tune covariant matrix in cluster, so that the pull distribution on DCA become normal (1 sigma width = 1). The tuned cluster position error may not be exactly width/sqrt(12) due to Kalman filter approximate the square uncertainty distribution with a Gauss distribution.

 

Action Item [Haiwang]: modify the error matrix to properly reflect covariant matrix of cluster position and use it in the downstream Kalman fit

 

 

 

 

______________________________

 

Jin HUANG, Ph. D.

 

Associate Physicist

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, November 14, 2016 3:37 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 Nov 15th, 1PM EST @ 2-219

 

Hello everyone,

 

This is a reminder for a regular sPHENIX simulation and software meeting, Tue Nov 15th, 1PM EST @ 2-219

 

Currently on agenda are continuing investigations on the following topics:

•            DCA fitting quality check with an eye towards 3-D DCA tagging of b-jets  - Haiwang Yu

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=1936 , 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, Ph. D.

 

Associate Physicist

Brookhaven National Laboratory

Physics Department, Bldg 510 C

Upton, NY 11973-5000

 

Office: 631-344-5898

Cell:   757-604-9946

______________________________