[Erd108] [External] Re: Additional simulation request

Wed Jul 17 15:42:54 EDT 2024

Dear Sourav and All,

I extracted the results from my fast simulations for the phi resolution.
Please find the attached file. I can see there is a significant impact on
phi resolution.

Regards,
Shyam

On Wed, Jul 17, 2024 at 6:44 PM Sourav Tarafdar <stara at jlab.org> wrote:

> Hi Alexander,
>
> Point well taken but I am not sure who is involved in DIRC simulation. If
> possible we probably should get together during collaboration meeting with
> available DIRC expert (if anyone is attending) to get their insight in this
> matter.
>
> Cheers,
> Sourav
> ------------------------------
> *From:* Kiselev, Alexander <ayk at bnl.gov>
> *Sent:* Wednesday, July 17, 2024 12:22 PM
> *To:* Sourav Tarafdar <stara at jlab.org>; Kondo Gnanvo <kagnanvo at jlab.org>;
> Shyam Kumar <shyam055119 at gmail.com>
> *Cc:* erd108 at jlab.org <erd108 at jlab.org>
> *Subject:* Re: [Erd108] [External] Re: Additional simulation request
>
>   Hi All,
>
>   Given how serious this problem potentially is for the hpDIRC, I'm still
> a bit puzzled why no one from the experts looked into a feasibility of PID
> event reconstruction with it without using tracking information for any
> other purposes but a track-to-ring matching.
>
>   I'm not talking about writing a full reconstruction suite. Just a
> conceptual consideration with a simple outcome: the approach is feasible
> (then one can think about estimates and / or implementation) or outright
> excluded (then minimizing the material budget is of a paramount
> importance). From a technical perspective, it is a matter of systematically
> shifting reconstructed track parameters by few mrad, and checking whether a
> chi^2-like measure of how well a PID hypothesis matches the measured hits
> changes substantially or it does not. Big deal.
>
>   Everybody understands that if you have N points on a 2D plane, which are
> supposed to be distributed along a circumference of a circle of unknown
> radius, one can solve the problem either with or without an a priori
> knowledge of where the center of the circle is. In one case you have a
> problem with 2N-1 degrees of freedom. In the other case - with 2N-3. Of
> course, this cannot work well if all the hits are sitting on one side of
> the circle. Is it really the case for hpDIRC images (which are not circles,
> but then what exactly is the difference?). Otherwise, an ultimately correct
> hpDIRC reconstruction code may actually want to add track parameters as
> Lagrange multipliers with a cov. matrix given by tracking to the problem,
> and re-tune them along with obtaining a PID hypothesis. My 2 cents.
>
>   Cheers,
>     Alexander.
>
> ------------------------------
> *From:* Erd108 <erd108-bounces at jlab.org> on behalf of Sourav Tarafdar <
> stara at jlab.org>
> *Sent:* Wednesday, July 17, 2024 11:57 AM
> *To:* Kondo Gnanvo <kagnanvo at jlab.org>; Shyam Kumar <shyam055119 at gmail.com
> >
> *Cc:* erd108 at jlab.org <erd108 at jlab.org>
> *Subject:* Re: [Erd108] [External] Re: Additional simulation request
>
> Hi Kondo,
>
> You are right for the momentum range for both DIRC and ToF. At momentum of
> >= 1 GeV is where the tracking angular resolution will help with DIRC PID ,
> if I am not mistaken. 1-3 GeV is where the problem with multiple scattering
> is coming up.
>
> best regards,
> Sourav
> ------------------------------
> *From:* Kondo Gnanvo <kagnanvo at jlab.org>
> *Sent:* Wednesday, July 17, 2024 11:53 AM
> *To:* Sourav Tarafdar <stara at jlab.org>; Shyam Kumar <shyam055119 at gmail.com
> >
> *Cc:* Matthew Posik <posik at temple.edu>; Gnanvo, Kondo (kg6cq) <
> kg6cq at virginia.edu>; erd108 at jlab.org <erd108 at jlab.org>
> *Subject:* Re: [Erd108] [External] Re: Additional simulation request
>
> One quick question,
> Is the tracking needed for PID with DIRC at low momenta (<1GeV) or rather
> a higher momenta (6GeV)
> I would expect the ToF to basically cover the low momenta region
> Best regards
> Kondo
>
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> ------------------------------
> *From:* Sourav Tarafdar <stara at jlab.org>
> *Sent:* Wednesday, July 17, 2024 11:48:46 AM
> *To:* Shyam Kumar <shyam055119 at gmail.com>
> *Cc:* Matthew Posik <posik at temple.edu>; Kondo Gnanvo <kagnanvo at jlab.org>;
> Gnanvo, Kondo (kg6cq) <kg6cq at virginia.edu>; erd108 at jlab.org <
> erd108 at jlab.org>
> *Subject:* Re: [Erd108] [External] Re: Additional simulation request
>
> Thanks Shyam. The final numbers with 5% ToF material budget will be
> helpful in justifying not to increase the ToF material budget further. It
> will also affect the electron line shape at EMCAL (but anyway, EMCAL is not
> my or this mailing list main concern). At some point one need to see if one
> can do better than current 3.5 mrad based on Matt's study in reality to
> improve DIRC performance (may be not at the level of "high performance"
> )but reasonable pi/K separation (again that has to come from PID group).
>
> Best regards,
> Sourav
>
> ------------------------------
> *From:* Shyam Kumar <shyam055119 at gmail.com>
> *Sent:* Wednesday, July 17, 2024 11:25 AM
> *To:* Sourav Tarafdar <stara at jlab.org>
> *Cc:* Matthew Posik <posik at temple.edu>; Kondo Gnanvo <kagnanvo at jlab.org>;
> Gnanvo, Kondo (kg6cq) <kg6cq at virginia.edu>; erd108 at jlab.org <
> erd108 at jlab.org>
> *Subject:* Re: [Erd108] [External] Re: Additional simulation request
>
> Dear Matt and Sourav,
>
> The idea of Matt of the formation of fast tracklets can help there. As I
> understand, it may help but will need to do some studies.
>
>
> Regards,
> Shyam
>
>
>

-- 
*Thanks and Regards, *

*-------------------------------------------------------Shyam Kumar,*

*Postdoctoral Fellow,*
*Istituto Nazionale di Fisica Nucleare (INFN), Bari, Italy*
*alt. email: shyam.kumar at cern.ch <shyam.kumar at cern.ch>*
*shyam <shyam at rcf.rhic.bnl.gov>.kumar at ba.infn.it <kumar at ba.infn.it>*
*-------------------------------------------------------*
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