sPHENIX tracking discussion

[Genki Nukazuka <genki.nukazuka AT riken.jp>]

Dear Dennis,

Thank you for your advice.

This discussion was already done in the INTT meeting a few weeks ago, actually. Hot channel rejection can be dangerous as a part of the data is thrown away, so we decided to take a reasonable time to provide codes to sPHENIX that satisfy enough quality. Instead of the latest one, a dummy module was put into the software repository so that people could start (pretend) using it. For further implementation and tests of the codes, we need to take some time, but not too long. We already took a moderate and reasonable way to go. Don't worry.

The assignment of INTT software tasks should be led by Takashi since he is the INTT software coordinator, by the way.

Best regards,

Genki

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Genki Nukazuka

Special Postdoctoral Researcher

RIKEN/RBRC

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差出人: Perepelitsa, Dennis <dvp AT bnl.gov>
送信日時: 2024年7月10日 12:34
宛先: Genki Nukazuka <genki.nukazuka AT riken.jp>
CC: Hao-Ren Jheng <hrjheng AT mit.edu>; sphenix-intt-l AT lists.bnl.gov <sphenix-intt-l AT lists.bnl.gov>; Osborn, Joseph <josborn1 AT bnl.gov>; Nagle, James <Jamie.nagle AT colorado.edu>; Joe Osborn <osbornjd91 AT gmail.com>; Anthony Frawley via sPHENIX-tracking-l <sphenix-tracking-l AT lists.bnl.gov>
件名: Re: [[Sphenix-intt-l] ] Question about silicon seeds/INTT QA

 

Hi Genki and all,

I and many others appreciate the hard work done being done by groups working on the INTT.

However, I have been following this thread, and I am becoming concerned about delays in putting critical INTT code into the official sPHENIX reconstruction.

There are time-critical checks that the Collaboration is trying to do, and it would be most helpful to put in the best map we have into the official production, ASAP, essentially now. I think it is OK if it is not the final version, and analyzers will understand that.

Can the INTT group identify a responsible person who will focus on this? What is the prospect of having an initial module like this by tomorrow?

Dennis

On Jul 10, 2024, at 9:29 AM, Genki Nukazuka <genki.nukazuka AT riken.jp> wrote:

Dear Hao-Ren,

It's good to add the hot channel rejection process to official data production. Joseph uploaded a dummy module, which will be replaced by another module, for the implementation of the production chain, in my understanding. I don't know who works on adding the process to the official production chain. Also, we, the INTT group, need to finish the hot channel rejection procedure. It needs to be optimized. Since the rejection needs to be done before clustering, updating the rejection process too many times is not a good idea concerning computing resources, in my opinion.

Best regards,

Genki

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Genki Nukazuka

Special Postdoctoral Researcher

RIKEN/RBRC

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 差出人: Hao-Ren Jheng
送信: 2024 年 7 月 10 日 (水曜日) 8:57
宛先: Genki Nukazuka
Cc: sphenix-intt-l AT lists.bnl.gov; Osborn, Joseph; Nagle, James; Joe Osborn; Anthony Frawley via sPHENIX-tracking-l
件名: Re: [[Sphenix-intt-l] ] Question about silicon seeds/INTT QA 

Dear Genki and Jaein,

Thanks for your feedback.  

These offline QA are produced with the sPHENIX production and software, so a follow-up question would be: is there a plan to implement the hot channel mask for Run2024, or is it already an on-going task, to improve the seeding aside from tuning the parameters? (I do not know if this is a valid question or it makes any sense)

Best,

Hao-Ren

*In the MVTX group we recently had an updated set of pixel masks ready and remaining tasks are being worked on, If I am not mistaken

On Jul 9, 2024, at 20:54, Genki Nukazuka <genki.nukazuka AT riken.jp> wrote:

Dear Hao-Ren,

I remember that you showed this plot in the shift change meeting on June/19 (https://docs.google.com/document/d/1s0KTIgEyfS9PbAy6WVfta86m8bVLP7QNJ0KBexweTK4/edit), and I commented at that time. This is due to some hot channels in the INTT data. You need to remove them before clustering. You can ask Jaein (jaeinhwang213 AT gmail.com) for technical help. If you need INTT cluster data with hot channel removal right now, I can make it quickly.

Best,

Genki

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Genki Nukazuka

Special Postdoctoral Researcher

RIKEN/RBRC

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差出人: sphenix-intt-l-request AT lists.bnl.gov <sphenix-intt-l-request AT lists.bnl.gov> が Osborn, Joseph <josborn1 AT bnl.gov> の代理で送信
送信日時: 2024年7月9日 18:24
宛先: sphenix-intt-l AT lists.bnl.gov <sphenix-intt-l AT lists.bnl.gov>; Hao-Ren Jheng <hrjheng AT mit.edu>
CC: Nagle, James <Jamie.nagle AT colorado.edu>; Joe Osborn <osbornjd91 AT gmail.com>; Anthony Frawley via sPHENIX-tracking-l <sphenix-tracking-l AT lists.bnl.gov>
件名: Re: [[Sphenix-intt-l] ] Question about silicon seeds/INTT QA

 

Hi all, and adding the tracking list for further comments others might have,

Here are a few comments from the tracking side of things.

1. The seeding algorithm uses wide search windows right now to try to ensure that we get some correlation between the silicon. These windows were blown up based on the previous MVTX ideal geometry, where there was significant layer to layer rotation (i.e. the ideal geometry was wrong compared to how the MVTX was actually constructed). That rotation has now been implemented to reduce the residuals, so these windows likely need to be re-tuned.
2. The silicon seeding algorithm creates (at a minimum) triplets in the 5 layers. In our simulation, we deploy this algorithm in the MVTX to reduce the presence of duplicates. In the real data, with the misalignment, we found we could not find anything in the MVTX alone (again, before the rotation alignment fix), so we expanded the seeding algorithm to search in the MVTX+INTT. This means you likely get a nontrivial background of fake tracks where 2 layers of the MVTX match to a single layer in the INTT.
3. Silicon seeds should not be considered as real tracks. We need to make some basic quality criteria to reduce the presence of background, mismatches, etc. One of these that we have been using in alignment studies is that the track must have 5 measurements on it, for exactly this reason.

I'm happy to chat about this more. The track reconstruction is going to continuously need to be optimized as we learn more about the alignment, backgrounds, timing correlation between the silicon subsystems, etc. Right now we need to make selections to have high purity at a cost of efficiency, and as we learn more about the data we will be able to re-tune these to improve the efficiency with a cost to purity.

Joe Osborn

___________________________

Joe Osborn, Ph.D

Physics Department

Brookhaven National Laboratory

josborn1 AT bnl.gov

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From: sphenix-intt-l-request AT lists.bnl.gov on behalf of Hao-Ren Jheng
Sent: Tuesday, July 9, 2024 10:28 AM
To: sphenix-intt-l AT lists.bnl.gov
Cc: Nagle, James; Joe Osborn
Subject: [[Sphenix-intt-l] ] Question about silicon seeds/INTT QA 

Dear INTT group and experts (cc RC, Jamie, and tracking expert, Joe),

I have been working on the silicon seeds offline QA and have one question that requires INTT experts’ input.
We have one QA plot showing the correlation between number of MVTX clusters v.s number of INTT clusters per silicon-only track, and we are seeing a large fraction of tracks having only 1 INTT cluster (please see the attached plot).
Do you have an idea why this is the case and what could be the cause of it?

Best,
Hao-Ren

Dennis V. Perepelitsa
Associate Professor, Physics Department
University of Colorado Boulder