sPHENIX discussion of software

["Frawley, Anthony" <afrawley AT fsu.edu>]

Hi All,

Following up on the discussion at the simulations meeting today, I looked into how the Upsilon mass resolution depends on TPC cluster resolution. I varied the TPC resolution using the PHG4TPCSpaceChargeDistortion:: setPrecision() method. Note that the numbers I used are very large and not realistic for space charge distortion effects. I am just using this as a convenient way to make the TPC resolution worse.

The tests were done using single Upsilons and the code from Haiwang's KalmanPatReco development area built against the new.1 libraries.  The silicon layers are all ladders, and the TPC is 60 layers out to 78 cm.  The results are:

set_precision        cluster resolution RMS (microns)        mass RMS (MeV)
0.040                       179.8                                                         109.2 +/- 2.3
0.030                       143.5                                                           93.3 +/- 2.4
0.025                       127.4                                                          78.3 +/- 1.7
0.020                       111.9                                                          74.7 +/- 1.6
0.001                       75.8                                                             60.1 +/- 1.5

where 0.001 is the default setting for the precision parameter.

Conclusion: The extremely good momentum resolution we have been seeing is actually due to the TPC cluster resolution (obtained with the default space charge precision) being too good. Not surprising. It is clear though that the performance of the tracker depends very strongly on the TPC cluster resolution.

How well do we think the TPC space point resolution can be estimated?

Thanks

Tony

---

From: sPHENIX-l <sphenix-l-bounces AT lists.bnl.gov> on behalf of Huang, Jin <jhuang AT bnl.gov>
Sent: Monday, May 15, 2017 9:33 AM
To: 'sphenix-software-l AT lists.bnl.gov'
Cc: 'sphenix-l AT lists.bnl.gov'
Subject: [Sphenix-l] [reminder] sPHENIX simulation and software meeting, Tue May 16th, 1PM EST @ 2-219.

 

Hello everyone,

 

We will have a regular sPHENIX simulation and software meeting, Tue May 16th, 1PM EST @ 2-219.

 

The main topic of the meeting will be reviewing production software status including tracking and calorimetry. Further topics will be welcomed too.

 

The agenda page is at https://indico.bnl.gov/conferenceDisplay.py?confId=2693  , for which the common modification password is "1008"

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Looking forward to talking to you.

 

Cheers,

 

Jin

 

 

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Jin HUANG

 

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