STAR HardProbes PWG

[Nihar Sahoo <nihar AT rcf.rhic.bnl.gov>]

Hello Raghav,

Thank you for your good comment and suggestion.
I tried to include your comment and updated version can be found here: 
https://drupal.star.bnl.gov/STAR/system/files/STAR_Hot_QCD_White_Paper_Sep12.pdf

My replies to your comment can be found inline.
Please have a look and let us know if you any further comment and 
suggestion.

Thank you
Nihar for the conveners

On 2022-09-12 00:12, Raghav Kunnawalkam Elayavalli wrote:
> Dear Nihar, Barbara, Yi, Sooraj, all
>
> Apologies for the delay from my side. I have a few comments on the
> current writeup of our hot qcd white paper on the jet section and the
> few sentences in promised related to the time/temperature dependence.
> Based on the discussion during last week’s meeting, I also discuss a
> few words on a general paragraph related to jets that we can present
> as a bigger picture. Your thoughts and comments are most welcome.
>
> Line numbers are based on the pdf attached below.
> L 62 - instead of ’shorter and shorter length scales’ ->
> ‘varying scales, from the macroscopic to microscopic lengths’

I like your phrase but I think it is Ok to keep as it is, because this 
phrase was used in the last LRP2015 on that context and it is shorter 
than your suggestion.

> L 63 - the QGP’s transport properties
Done
> L 63-66- you mention the usefulness of jets and then in the next
> sentence describe what they are… so maybe reverse this order?
Done
> L 66 - loses a fraction of its energy
Done
> L 69-71- this sentence seems a bit redundant here, especially when
> considering the next sentence.
Done
> L 75 - jet quenching -> jet-medium interactions (of which quenching is
> a part)
Done
> L 76 and later on - I think we should fold in our studies on pp
> substructure as a necessary prerequisite towards quantitative studies
> of the QGP evolution in both its perturbative description and
> hadronization (which is still unknown). The way its currently written
> seems a bit like its something else that we do on the side with the
> connection unclear.
> It would be good to emphasize here that one of the next steps in
> studying the QGP is to quantify its properties during its evolution.
> And one way in which we can do that is to use jets via their
> multi-scale evolution from pQCD to npQCD and hadronization. This
> provides a natural timescale that one can exploit in heavy ion
> collisions to then extract a temperature dependence of the transport
> parameters such as \hat{q}. This is the reason why we want to quantify
> jet topologies and that requires us to understand the substructure and
> clustering tree in pp collisions. So I would rephrase the sentence in
> L 76 with something along the lines of what i mentioned above and head
> into the next paragraphs.
Please have a look at the updated version and let us know if you have 
further comments.

> L 99 - I understand the point here but i would probably rephrase this
> as a feature than a bug (which is how its written with the emphasis on
> a measurement ‘bias’). Different jets lose energy differently and
> potentially same jets lose energy differently (depending on the
> strength of fluctuations vs path length for example). Such a system
> essentially forces us to make all possible types of measurements at
> varying kinematics and selections so that one can put the pieces of
> the puzzle together.
Modified and mentioned the underlying possible physics. Please have a 
look.

> L 101 - this paragraph seems overly technical, especially with the
> comparison of pp data to pythia which doesnt really add much to the
> discussion here.
It is now modified. Please have a look.

> L 113 - This can just be on jet substructure or something like jet-qgp
> space-time evolution where the pp is not only a reference, but a
> necessary step to comprehend before we move to heavy ions. We have
> measured the evolution of jet substructure along its shower and found
> deviations from perturbative description of the splitting kinematics
> for later emissions/splits. This points to significant
> non-perturbative contribution to the description of jet substructure
> along the jet where at a particular formation time which can be
> experimentally measured.
> So this is where we can bring back a bigger picture to summarize -
> From our measurements, we have two sets of studies which are
> complementary to each other with the scattering tomography and the
> space-time evolution picture. Both of which are necessary and have
> extensions to heavy flavor, such as heavy flavor jets and resonances,
> and other aspects we are yet to study about the medium such as hadron
> production affected by jet quenching etc.

This part I am not sure what I need to include in the jet substructure 
para.
Although that para I tried to modify a bit to align what you have 
mentioned here. If you want to include more info there for a bigger 
picture what we have learned so far, please let us know.


> Cheers
> Raghav
>
> **************************************
> First Name - Raghav
> Last Name - Kunnawalkam Elayavalli
> email - raghav.ke AT vanderbilt.edu
> website - https://www.raghavke.me [2]
>
> RHIC/AGS UEC member
> Assistant Professor of Physics
> Stevenson Center 6410
> Physics & Astronomy Department
> Vanderbilt University
> Nashville, TN 37235-1807
> <he/them>
> **************************************
>
> > On Sep 5, 2022, at 6:43 AM, Nihar Sahoo via Star-hp-l
> > <star-hp-l AT lists.bnl.gov> wrote:
> >
> > Hello All,
> >
> > We will have our regular HP-pwg meeting this Thursday (Sep 8th) at
> > 10 AM BNL time. Let us know if you want to present and update your
> > analysis.
> >
> > As you may know from the minutes of last week pwgc meeting
> > (Rongrong's email), currently conveners from all pwg are preparing a
> > first draft of STAR Hot QCD white paper which should be ready by Sep
> > 7-9; then that will be sent to the collaboration for comments during
> > the weekend before the collaboration meeting. And the final white
> > papers is aimed to be ready by Sep. 21st. It is very tight schedule.
> >
> > Hence, this week we will discuss on the STAR Hot QCD white paper and
> > also STAR contribution for next LRP. So please try to join this week
> > to discuss more on this topic and it would be helpful for us to get
> > your inputs. If you are interested in to contribute, please let us
> > know.
> >
> > HP working group weekly meeting info:
> https://drupal.star.bnl.gov/STAR/pwg/Hard-Probes/Weekly-HP-PWG-meeting
> > Join ZoomGov Meeting
> https://bnl.zoomgov.com/j/1611419615?pwd=VW1hNm43ZDd5d2EvK2R4aEJsQ2ZNZz09
> > [1]
> >
> > Meeting ID: 161 141 9615
> > Passcode: 744968
> >
> > Regards,
> > Barbara, Yi, Sooraj, and Nihar
> > _______________________________________________
> > Star-hp-l mailing list
> > Star-hp-l AT lists.bnl.gov
> > https://lists.bnl.gov/mailman/listinfo/star-hp-l
>
>
>
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