STAR HardProbes PWG

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

Hello Isaac,

Thank you for implementing my comments. Please find my reply inline.
With these, I sign off.

Best
Nihar
On 2023-11-27 15:59, Mooney, Isaac wrote:
> Hi Nihar,
>
> Thanks for the really helpful edits. Please see my responses inline
> below. The new version is uploaded to the node as v2. Let me know if
> you have any more comments.
>
> -Isaac
>
> > On Nov 26, 2023, at 5:07 PM, Nihar Sahoo <nihar AT rcf.rhic.bnl.gov> 
> > wrote:
> >
> > Hello Isaac,
> >
> > Thank you for sharing your DNP overview talk. It covers nicely all 
> > subject on HotQCD STAR-jet physics.
> > Have you checked the time duration of this talk?
>         > It’s 35' + 10'.
Ok, then you must have practiced to finish in it.
> > Besides, find my comments for your consideration.
> >
> >
> > Slide15: "Observe also in ALICE: …but tension with models at high kT 
> > for narrow splits" Is this true for STAR also? If not, please add a 
> > text there about STAR observation.
>         > The statement about the models’ agreement with STAR data is
> on the previous slide. I think it should be okay to flip to this slide
> and mention the ALICE model tension specifically, so I’ve left it as
> is, but let me know what you think about that.
> > For ALICE plot: if you could show ln(R/DR) plot that would be more 
> > informative. Then you can show one slice of ln(kT) plot.
> > [just for your consideration]
>         > I’ve changed it to the two panels of ln(R/DR) for two
> different kT selections (no plot of the ln(kT) for an R selection).
> > Slide14:
> > Would it be interesting to point it out why on slide15, "tension with 
> > models at high kT for narrow splits" and on groomed mass case "MCs are 
> > in good agreement."? Do we understand here why this is the case?
>         > I’m not sure what you mean here. The MCs are in good
> agreement with either the log(kT) or mu results. It may have been a
> confusion related to how I worded the comment about ALICE, making it
> seem that both their results and the STAR results had tension with
> models. I added a period after “harder splits are wider” to make it
> clear the similarity is in the trends, not the agreement/disagreement
> with MCs. Let me know if it’s still not clear.
Now, it looks good. And thank you for your clarification.

> > Slide17: "Consistent with time evolution to non-perturbative regime;" 
> > -> is not that "Consistent with time evolution to perturbative 
> > regime;" like Altarelli-Parisi evolution Eq. That is pQCD at least 1st 
> > splitting?
>         > I think there may be a misunderstanding here too. I meant
> that with time/split number, the splits are (not inconsistent with)
> undergoing an evolution from perturbative to non-perturbative. So yes
> the AP kernel 1/z behavior is seen for the first splits, but by the
> third it it’s roughly flat. Maybe I’m missing what you were getting at
> with your comment though.
Ok, I got it now. I misunderstood it.
> > Slide19: "With conservative systematic uncertainties in biased pop., 
> > no modification in AA observed"
> > We know Tanmay is working on it and knowing this result was very last 
> > time approved for QM23. I would prefer not to sell it as "no 
> > modification in AA"; Could we be a bit silent at this moment? What do 
> > you think? Just mentioning within uncertainty pp and AA are 
> > consistent. Period.
>         > I thought the caveats in that bullet point were enough to
> make it clear I wasn’t trying to make much of a physics conclusion,
> but I’m fine with your suggestion, so I changed it (although this plot
> is the central-peripheral comparison, so I wrote “girth in peripheral
> and central collisions are consistent”.
> > Slide21: What is "R_L" here?  "NP" -> non-perturbative or npQCD
>         > R_L is the longest side of the polygon formed by the N
> particles in the ENC. So e.g. for EEEC it would be the longest side of
> the triangle formed by the three particle correlation. I’ve added a
> cartoon on the slide to make it clear. For the EEC, RL and DeltaR
> would be equivalent. The only reason I didn’t just make the ENC
> equation in DeltaR instead of RL is because it would no longer
> generalize to higher-point correlations. But hopefully it’s fine now
> with the cartoon.
> > Slide23: Have we shown STAR EEC plot with x-axis "<p_T,jet>Delta_R" as 
> > STAR preliminary? Probably I missed that.
> >              What <p_T,jet> we use in our STAR plot? And is that 
> > corrected?
>         > The <pT> on the x-axis is from Pythia, so the data hasn’t
> been updated. And it was shown this way at the CFNS workshop a few
> weeks ago.
Then I would suggest to add "<p_T,jet> from PYTHIA" inside the figure 
and point this out while speaking.
Have all other experiments also done the same (from PYTHIA)?

> > Slide29: lower right plot needs reference (the guy, who made this, 
> > will feel good and need some citation :))
>         > Added the reference. Sorry, I was planning to cite it I just
> needed to find where you first showed it.
Thank you
> > On this plot, you circled it, and you could also highlight why in 
> > inclusive jet case we don't see jet R dependence unlike other cases?
>         > I’m not sure what you mean here, since the inclusive jet
> case only extends to R = 0.4, and at 0.4 in the h+jet case, there is
> also consistency between R = 0.2 and 0.4. Are you referring instead to
> the AJ measurement where we did see a radius dependence where by 0.4
> quenched energy is largely recovered? I think that could be an
> unnecessary complication to mention and explain.

in STAR we observed inclusive jet RAA and Delta_pT-shift (two green 
markers in this fig) are independent of jet R (for 0.2 and 0.4), unlike 
semi-inclusive jet measurements at STAR and ALICE. This is important to 
highlight.
(STAR Aj measurement also shows jet R dependance of modification in the 
same line what semi-inclusive jet measurement shows in STAR, but as we 
are discussing here only Delta_pT-shift so need to mention it; you could 
add a short sentence to highlight this).
But it is up to you how you want to present your slides.

> > Slide39: left side plot needs reference
>         >  Done.
> > Slide40: "Possible sign of jet diffusion wake: enhanced 
> > baryon-to-meson ratio in AA" -> After Reading this paper, what they 
> > mainly conclude because of "via parton coalescence" not exactly 
> > diffusion wake. Enhancement in b-to-m ratio should come from 
> > hadronization chemistry.
> > So I would prefer to write "Possible sign of parton coalescence in 
> > jet". If you agree.
>         > The authors do say "unambiguous evidence for jet-induced
> medium excitations in heavy-ion collisions”, but I understand “wake”
> is a charged word, so I’m fine with changing it.
> > Best
> > Nihar
> >
> >
> >
> > On 2023-11-23 03:46, Mooney, Isaac via Star-hp-l wrote:
> > > Hi Nihar, Yi, all,
> > > No need to read this during the holiday for those in the US. This is 
> > > a
> > > draft of a talk for DNP. The invitation wasn’t through STC, but I
> > > would still like it to be approved by STAR. Sorry it’s late, but for
> > > what it's worth, the talk is on the last day of the conference (Dec.
> > > 1st), and it’s already been through a bit of review here at Yale. (I
> > > may still get some more comments, in which case I’ll let you know if
> > > there is a new version).
> > > Thanks, and Happy Thanksgiving!
> > > Isaac
> > > > On Nov 23, 2023, at 4:34 AM, webmaster--- via Star-hp-l 
> > > > <star-hp-l AT lists.bnl.gov> wrote:
> > > > Dear Star-hp-l AT lists.bnl.gov members,
> > > > Isaac Mooney (isaac.mooney AT yale.edu) has submitted a material for a 
> > > > review,
> > > > please have a look:
> > > > https://drupal.star.bnl.gov/STAR/node/66065
> > > > Deadline: 2023-10-07
> > > > ---
> > > > If you have any problems with the review process, please contact
> > > > webmaster@http://www.star.bnl.gov/
> > > > _______________________________________________
> > > > Star-hp-l mailing list
> > > > Star-hp-l AT lists.bnl.gov
> > > > https://lists.bnl.gov/mailman/listinfo/star-hp-l
> > > _______________________________________________
> > > Star-hp-l mailing list
> > > Star-hp-l AT lists.bnl.gov
> > > https://lists.bnl.gov/mailman/listinfo/star-hp-l