STAR HardProbes PWG

[Youqi Song <youqi.song AT yale.edu>]

Hi conveners,

I have added two backup slides in the end for a discussion of R-dependence of r_c with simulations in PYTHIA.

Also it would be great if you could push my slides to star-talks if there's no additional comment. Thank you!

Best,

Youqi

On Thu, Feb 1, 2024 at 6:59 AM Nihar Sahoo <nihar AT rcf.rhic.bnl.gov> wrote:

Hello Youqi,

I don't have any comment. I sign off.

Best
Nihar

On 2024-02-01 01:25, Youqi Song wrote:
> Hi Nihar,
>
> Sounds good! I will bring up these discussions again next time I
> present at the PWG meeting. Please let me know if you have any
> additional comments. Thank you!
>
> Best,
> Youqi
>
> On Tue, Jan 30, 2024 at 9:24 PM Nihar Sahoo <nihar AT rcf.rhic.bnl.gov>
> wrote:
>
>> Hello Youqi,
>>
>> Thank you for your replies. Please find my reply below.
>>
>>> When you said to make a 2D plot of zg vs Rg in pp data, do you
>> mean
>>> making an internal plot with uncorrected data?
>> I mean not for this presentation. you can present these results at
>> our
>> next pwg-meeting.
>>
>>> rc vs formation time: I have made this plot with uncorrected data
>> and
>>> it is in slide 5 of
>>>
>>
> https://drupal.star.bnl.gov/STAR/system/files/pwg_meeting_051123.pdf.
>>> I have temporarily shifted away from measuring rc with respect to
>> the
>>> formation time, because after our PWG discussion in May, I am also
>> not
>>> sure if a formation time defined in terms of leading hadron
>> kinematics
>>> is meaningful. And my conclusion from that discussion is that if
>> I'd
>>> like to make connection to formation time, then I need to measure
>> it
>>> with groomed subjets, which are better proxies for partons.
>> Thank you for pointing this presentation.
>> Yes, that is true.
>> OK, let's discuss at your next presentation. Please bring this
>> discuss
>> again also.
>>
>> Best
>> Nihar
>>
>> On 2024-01-30 07:24, Youqi Song wrote:
>>> Hi Nihar,
>>>
>>> Thanks for the comments! Please find my response below. I have
>> also
>>> updated my slides on drupal.
>>>
>>> Slide 7: "PYTHIA No hadronization" means I ran PYTHIA specifically
>>> with a flag "HadronLevel:Hadronize = off".
>>>
>>> Slide 11: t_1,2,3 are "Lines of constant formation time" as I have
>> as
>>> a bullet point on the slide. I will also make sure to verbally
>>> emphasize that as I present. The equation that I have on the slide
>>> 𝑧 = 1/2  [1−√(1−2/𝑡𝐸(1−cos(𝜃)) )  ]) gives a
>>> function of z(theta) once the value of (t*E) is fixed, and as I
>> vary
>>> (t*E) to different values, for example, 50, 200, 800, I get
>> different
>>> functions of z(theta).
>>>
>>> When you said to make a 2D plot of zg vs Rg in pp data, do you
>> mean
>>> making an internal plot with uncorrected data?
>>>
>>> Slide 15: I have weakened the statement to "In the future, one
>> might
>>> potentially measure this in heavy-ion collisions!"
>>>
>>> Slide 18: I am not using any hard-core selection. I have changed
>> the
>>> statement to "Weak dependence on jet 𝒑_𝐓 in 20-40 GeV"
>>>
>>> rc vs formation time: I have made this plot with uncorrected data
>> and
>>> it is in slide 5 of
>>>
>>
> https://drupal.star.bnl.gov/STAR/system/files/pwg_meeting_051123.pdf.
>>> I have temporarily shifted away from measuring rc with respect to
>> the
>>> formation time, because after our PWG discussion in May, I am also
>> not
>>> sure if a formation time defined in terms of leading hadron
>> kinematics
>>> is meaningful. And my conclusion from that discussion is that if
>> I'd
>>> like to make connection to formation time, then I need to measure
>> it
>>> with groomed subjets, which are better proxies for partons.
>>>
>>> Best,
>>> Youqi
>>>
>>> On Mon, Jan 29, 2024 at 7:44 PM Nihar Sahoo via Star-hp-l
>>> <star-hp-l AT lists.bnl.gov> wrote:
>>>
>>>> Hello Youqi,
>>>>
>>>> Please find my comments and queries on your nice slides.
>>>>
>>>> Slide3:
>>>> Use “𝑔 ” -> it looks eerie in this way, you could mention
>>>> "subscript 𝑔 ”
>>>>
>>>> Slide7: "Note: Hadronization effects smear the distribution but
>>>> don’t
>>>> affect the correlations" and backup slide-28
>>>> In the backup slide, what is "PYTHIA No hadronization"? Do you
>> mean
>>>> you
>>>> check the effect of harmonization comparing parton level and with
>>>> hadrons using PYTHIA?
>>>> I forgot this discussion, can you pleas remind me again? Thank
>> you
>>>> _ you could show lower bottom plot of slide28 in this slide.
>>>>
>>>> Slide11:
>>>> Please provide reference to these expressions like formation time
>>>> and z.
>>>> Mention what are t_1,2,3 in side the plot? And what are 50, 200,
>> 800
>>>>
>>>> here?
>>>>
>>>> _Can you make similar right 2D-plot (zg vs Rg) for pp data ?
>>>>
>>>> Slide12:
>>>> Interesting!
>>>> This discussion mainly based on HERWIG.
>>>> I see now this "What will data tell us? Stay tuned! "
>>>> I would make it Bold and bigger, place somewhere people can see
>>>> this. It
>>>> is lost inside. [same on Slide11 too]
>>>>
>>>> Slide15:
>>>> -In the future, potentially measure this in heavy-ion collisions!
>> ->
>>>> I
>>>> have been seeing this but never commented yet. But I think in
>>>> heavy-ion,
>>>> it would not be that easy. So better to be cautious on this
>>>> statement.
>>>>
>>>> Slide18:
>>>> Weak dependence on jet 𝒑𝐓 -> probably not correct or
>> difficult
>>>> to say
>>>> because: 1) depend on jet selection (hardcore vs inclusive jet
>>>> population) 2) we don't show full jet pT range, say below 20
>> GeV/c.
>>>> Suggestion: either remove it or mention what jet population and
>>>> within
>>>> jet pt range.
>>>>
>>>> Not related to your this presentation:
>>>> As you have seen Charles presentation on r_c vs formation time
>> plot.
>>>>
>>>> Could you make similar plot for your analysis to see what is the
>>>> trend?
>>>> We can discuss at hp-pwg in your next presentation if you could.
>>>>
>>>> Thank you
>>>> Nihar
>>>>
>>>> <div class="pre">On 2024-01-30 02:13, webmaster--- via Star-hp-l
>>>> wrote:<blockquote>Dear <a
>>>> href=""mailto:Star-hp-l AT lists.bnl.gov">Star-hp-l AT lists.bnl.gov</a>
>>>> members,<br>
>>>> <br>
>>>> Youqi Song (<a
>>>> href=""mailto:youqi.song AT yale.edu">youqi.song AT yale.edu</a>) has
>>>> submitted
>>>> a material for a review,  <br>
>>>> please have a look:<br>
>>>> <a rel="noreferrer" target="_blank"
>>>>
>>>
>>
> href=""https://drupal.star.bnl.gov/STAR/node/66663">https://drupal.star.bnl.gov/STAR/node/66663</a><br>
>>>> <br>
>>>> Deadline: 2024-02-11<br>
>>>> ---<br>
>>>> If you have any problems with the review process, please contact
>>>> <br>
>>>> <a
>>>>
>>>
>>
> href=""mailto:webmaster AT www.star.bnl.gov">webmaster AT www.star.bnl.gov</a><br>
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