STAR HardProbes PWG

["Ma, Rongrong" <marr AT bnl.gov>]

Hello Nihar

Thanks for the additional comments. 

I changed T_c to T_pc on the slide. What I meant is that the temperature of 
the medium created at 54.4 GeV is closer to T_pc than that at 200 GeV. If the 
HFE v2 is gained at T much higher than T_pc, one would expect larger v2 at 
200 GeV, which is not the case in our data. 

Best
Rongrong

> On Oct 26, 2023, at 1:08 AM, Nihar Sahoo <nihar AT rcf.rhic.bnl.gov> wrote:
> 
> Hello Rongrong,
> 
> Thank you for addressing my comments. Your slides look good in shape now 
> from my side.
> I sign off.
> 
> However, just want to clarify myself on this point from you.
> 
>>> - "Charm quark gain v2 at T close to Tc" -> what is "Tc" here ? And
>>> What is the value of Tc? Why it is important?
>> Tc is the pseudo-critical temperature around 165 MeV. Here the point
>> is that the medium temperature created at 54.4 GeV is expected to be
> Then it would be good to mention "T_pc" (instead of T_c) as in literature 
> people use this notation.
> 
>> lower than that at 200 GeV. Yet, we see similar HFE v2, which
>> indicates that HFEs obtain their v2 mainly at T close to Tc.
>> Otherwise, one would see a larger v2 at 200 GeV than 54.4 GeV.
> It sounds like T_pc is close(/around) to 200 and 54 GeV collision energy. 
> Is this what you mean?
> 
> Thank you
> Nihar
> 
> 
> 
> On 2023-10-25 23:55, Ma, Rongrong wrote:
>> Hello Nihar
>> Thanks for your comments.
>> I thought a bit more on this. Since my talk is now really a STAR
>> overview talk (the organizer wanted me to give a RHIC physics overview
>> at the beginning), I think it is more appropriate to go through the
>> official approval procedure. So I have submitted the latest version on
>> Drupal (https://drupal.star.bnl.gov/STAR/node/65722) after addressing
>> your comments.
>> Please see my replies inline:
>>> On Oct 25, 2023, at 2:43 AM, Nihar Sahoo <nihar AT rcf.rhic.bnl.gov>
>>> wrote:
>>> Hello Rongrong,
>>> Thank you for sharing your nice presentation slides on heavy-flavor.
>>> Overall your slides look nice and capture all physics measurements
>>> of STAR.
>>> Here are my additions comments for your consideration.
>>> Slide5:
>>> - "Charm quark gain v2 at T close to Tc" -> what is "Tc" here ? And
>>> What is the value of Tc? Why it is important?
>> Tc is the pseudo-critical temperature around 165 MeV. Here the point
>> is that the medium temperature created at 54.4 GeV is expected to be
>> lower than that at 200 GeV. Yet, we see similar HFE v2, which
>> indicates that HFEs obtain their v2 mainly at T close to Tc.
>> Otherwise, one would see a larger v2 at 200 GeV than 54.4 GeV.
>>> Slide7:
>>> - "About a factor of 2 suppression…" -> Not clear, with respect to
>>> what
>> This is just another way of saying R_AA ~ 0.5. I added "compared to
>> p+p"
>>> Slide9:
>>> - Do you need to refer "QM2023" for this D^0+jet results? Same for
>>> next slide
>> Since I now treat this talk as a STAR talk, I do not think a reference
>> to QM2023 is needed.
>>> SLide13:
>>> - Better to motivate this result with QGP effect can smear
>>> D^0-D^0bar correlation. But uncertainty limits to pin down
>> I will mention this motivation verbally during my talk.
>>> Slide14:
>>> - "Coalescence is important" -> Do we need to mention also "at low
>>> pT"?
>> That's mostly true, but I do not feel this needs to be stated
>> explicitly on the slide since the two figures show results starting
>> from 1.5 GeV/c and 3 GeV/c.
>>> After Slide16, It would be good to summarize the key physics that we
>>> observed from open heavy flavor measurements at STAR. Otherwise
>>> people may be lost.
>> I added half of the original summary slide here.
>>> Slide18:
>>> -"Hint of rising trend toward low energy" -> Is that correct to
>>> comment within these uncertainties?
>> I removed that sub-bullet, but I will probably mention this verbally
>> as a question rather than a conclusion.
>>> _ You could hint to the "primodial" and "Regeneration" effects at
>>> high and low energies.
>> Added a sub-bullet.
>>> Slide19:
>>> -Could you comment on QGP thermal temp based on sequential
>>> suppression of quarkonia? That is important take away from these
>>> results at RHIC.
>> I added a half sentence on this. I intentionally kept it vague since
>> the connection is less straightforward as originally envisioned.
>>> SLide20-22:
>>> Physics motivation is missed here. Better to say a few words.
>> Added a bullet.
>>> Slide21-23:  better to motivate with other pesudoscalar meson
>>> results from FCV.
>> Added a figure from the Nature paper
>>> After Slide23: You could summarize the key physics learnt from QGP
>>> point of view.
>>> And then you can go to UPC J/psi results discussion to study other
>>> Physics not related to QGP.
>> Since I only have two slides on UPC J/psi, I kept the summary slide
>> at the end.
>> Best
>> Rongrong
>>> Best
>>> Nihar
>>> On 2023-10-24 20:33, Ma, Rongrong via Star-hp-l wrote:
>>>> Dear All
>>>> I was invited by the CFNS-npQCD workshop
>>>> (https://indico.cfnssbu.physics.sunysb.edu/event/110/) organizers
>>>> to
>>>> present an overview of the STAR heavy flavor results. Even though
>>>> it
>>>> is not a STAR talk, I will exclusively present STAR results. So I
>>>> would like to seek your comments and suggestions on my talk, a
>>>> first
>>>> draft of which can be found here:
>>> https://drupal.star.bnl.gov/STAR/system/files/RMa_CFNS_npQCD_v1.pdf.
>>>> Your feedback is more than welcome. Thanks.
>>>> Best
>>>> Rongrong
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