sPHENIX tracking discussion

["Osborn, Joe" <osbornjd AT ornl.gov>]

Hi Hugo,

 

This is a good suggestion anyway – if the truth track seeding + Acts fit gives similar resolution to (1), then the post MDC regression must be in the track fitter somehow.

 

Joe

 

---------------------------

 

Joe Osborn, Ph.D.

Postdoctoral Research Associate

Oak Ridge National Laboratory

osbornjd AT ornl.gov

(859)-433-8738

 

 

From: sPHENIX-tracking-l <sphenix-tracking-l-bounces AT lists.bnl.gov> on behalf of Hugo Pereira Da Costa via sPHENIX-tracking-l <sphenix-tracking-l AT lists.bnl.gov>
Date: Monday, May 24, 2021 at 3:39 PM
To: sphenix-tracking-l AT lists.bnl.gov <sphenix-tracking-l AT lists.bnl.gov>
Subject: [EXTERNAL] Re: [Sphenix-tracking-l] Upsilon mass resolution

Hi Tony,

if you feel like adding more entropy to the comparison, you could also try truth track finding plus either genfit or acts fit.

My recollection is that truth track finding + genfit is very close to 2).

I have not ran truth track finding + acts recently (last time I tried it gave about 80MeV/c2 resolution, but that might have been before the post MDC regressions.

 

Hugo

 

 

On 5/24/2021 1:32 PM, Anthony Frawley via sPHENIX-tracking-l wrote:

,Hi All,

 

I realized that I said something that is wrong at the meeting this morning, when we were discussing the onset of poorer Y(1S) mass resolution from our tracking code. Here is the correction.

 

The attached slides (made last week) show the Y(1S) mass resolution from our current code, obtained with different tracking options. In all cases, truth vertexing was used. Normal Acts chain seeding consists of PHTpcTracker + TPC tracklet vertex association + Si track seeding + truth vertexing + TPC-Si track matching.

 

The results are:

 

1) Normal Acts chain seeding + Acts track fit:                              95.0 +/- 2.6 MeV (used to be ~ 85 MeV)

2) Genfit track propagation + Genfit track fitting:                       73.8 +/- 1.7 MeV

3) Normal Acts chain seeding + Genfit final fit                             81.3 +/- 1.4 MeV

4) Normal Acts chain seeding + Acts fit + Genfit final fit:           82.9 +/- 1.9 MeV

 

So, using Genfit track propagation with a Genfit final fit DOES produce a significantly better mass resolution than using our normal track seeding with a Genfit final fit. Also, adding a final fit with Genfit after Acts fitting produces an improvement in mass resolution of ~15%.

 

The difference between 2) and 3) is interesting.

 

Tony

 

_______________________________________________

sPHENIX-tracking-l mailing list

sPHENIX-tracking-l AT lists.bnl.gov

https://lists.bnl.gov/mailman/listinfo/sphenix-tracking-l