STAR HardProbes PWG

[Sooraj Radhakrishnan <skradhakrishnan AT lbl.gov>]

Hi Tong,

   Thanks for preparing these nice slides. I have a few comments/questions

S5: second sub-bullet, is that referring to the comparison between the isobar species?

S8: Where is the plot from? There has to be some label on the collision system and MC used

S8: What is N_hard^i(b_NN) in these equations?

S8: How does this effect impact the RAA calculations in central events with the Ncoll scaling from Glauber?

S9: What is meant by synthetic PYHTHIA events?

S11: What do you mean by last sub-bullet? Isnt this already on slide 7+? What motivates this direction?.

thanks

Sooraj

On Thu, Oct 6, 2022 at 10:53 AM Nihar Sahoo via Star-hp-l <star-hp-l AT lists.bnl.gov> wrote:

Hello Tong,

I don't have any further comments. I sign off.

Cheers
Nihar

On 2022-10-06 09:28, Tong Liu wrote:
> Hi all,
>
> I just posted my latest draft version to drupal. Please take a look.
>
> Tong Liu
> Ph.D. Student '2023
> Physics Dept., Yale University
>
> Tel: 203-435-2130
>
> On Wed, Oct 5, 2022 at 5:49 PM Tong Liu <tong.liu AT yale.edu> wrote:
>
>> Hi all,
>>
>> Thanks for the comments; please find my responses to some of the
>> points below.
>> I just did a rehearsal at Yale a few hours ago, and I have got some
>> comments there as well. I'll update my slides ASAP once I addressed
>> those comments.
>>
>> Cheers,
>>
>> Tong Liu
>> Ph.D. Student '2023
>> Physics Dept., Yale University
>>
>> Tel: 203-435-2130
>>
>> Nihar:
>>
>> Slide13:
>>
>> I think it would be good if you could put some texts mentioning the
>>
>> reason for the shrinking of the uncertainty band compared to QM2022
>> and
>>
>> also results up to smaller <Npart>. What do you think?
>> I don’t think it’s a good idea, since the updated version is
>> clearly a more correct and accurate one, and that’s the message we
>> want to leave people with. The QM version is what it is out of the
>> box, but physically speaking we clearly should use the current 42 mb
>> simulation, and now that we have the right version I don’t think
>> we should mention the earlier one. That being said, I’d be happy
>> to put something in backup, so that if somebody asks we can have
>> something prepared.
>> Slide14:
>>
>> _ "More input needed in the next week" do you want to update
>> anything?
>>
>> I was planning to, but I don’t think I will be able to. I was
>> planning on another simulation, which was cutting it very close
>> already, then the Yale cluster was down the whole day yesterday;
>> I’m going to leave it till afterwards. This physics message should
>> already suffice.
>>
>> Barbara:
>>
>> - s15: the blue text is not so well visible on the green background.
>>
>> Yeah I’m not very happy about that either… but now that I just
>> did a rehearsal at Yale and I’m over time, I kinda want to lose
>> this slide altogether since it was supposed to be a transition slide
>> between my talk and the other low-pt spectrum talk back at QM.
>>
>> Yi:
>>
>> p5: Could you please tell me why there are many repeated lines for
>> Ru+Ru and Zr+Zr collisions on the right plot? What does that mean,
>> just for my own education?
>>
>> That’s to stress the point that we are alternating between Ru and
>> Zr collision on a run-by-run bases, instead of running Ru for half
>> the time and then switch to Zr for the remaining half. I’ll make
>> it more clear in the text.
>>
>> p6: Could you please remind me why there is a drop at 7 GeV on both
>> collisions?
>>
>> That’s because the p+p collision was larger than it’s supposed
>> to be at the range. Statistical fluctuations.
>>
>> p8, p9: What is this blue box for?
>>
>> That one is just to guide the eye where I want to temporarily block
>> the low pt region and let people focus on the high pt. It was a
>> solid block until Nihar asked me to make it transparent, but now it
>> looks like I’m trying to highlight it instead of blocking it…
>>
>> p13: Could you please remind me what Y^ch_pT is?
>>
>> Here I treat the synthetic PYTHIA events as real events and
>> calculate its Raa. In the Yale rehearsal people have suggested to
>> take the pT>5GeV part off since it’s in the text anyway
>>
>> On Wed, Oct 5, 2022 at 1:14 PM Yi Yang via Star-hp-l
>> <star-hp-l AT lists.bnl.gov> wrote:
>>
>> Hi Tong,
>>
>> Thanks a lot for the very nice slides. I have some minor
>> comments/suggestions for your consideration.
>> p3: the RAA formula, is it possible to let "RAA" to be in the same
>> line with the rest?
>> p5: Could you please tell me why there are many repeated lines for
>> Ru+Ru and Zr+Zr collisions on the right plot? What does that mean,
>> just for my own education?
>> p6: Could you please remind me why there is a drop at 7 GeV on both
>> collisions?
>> p8, p9: What is this blue box for?
>> p13: Could you please remind me what Y^ch_pT is?
>> p15: The last bullet in blue is a bit difficult to read, is it
>> possible to change to another color?
>>
>> Cheers,
>> Yi
>>
>> On Wed, Oct 5, 2022 at 10:32 PM Barbara Trzeciak via Star-hp-l
>> <star-hp-l AT lists.bnl.gov> wrote:
>>
>> Hi Tong,
>>
>> very nice slides, please find my additional comments below. WIth
>> these addressed I sign off.
>>
>> Cheers,
>> Barbara
>>
>> - s6: if p+p uncertainties are not preliminary, please add
>> references (we often do this on the plot itself  e.g."pp
>> uncertainty, PRL 91, 172302 (2003)")
>> - s11-13: somewhere there you should explain what is "HF-PYTHIA
>> N_hard" and "HF-PYTHIA Y_pT^ch > 5 GeV/c" (what's the difference
>> between them).
>> - s14: same question as Nihar, are you still planning on adding
>> something here ? I would suggest not to add too much of the last
>> moment studies.
>> - s15: the blue text is not so well visible on the green background.
>>
>> On Wed, Oct 5, 2022 at 2:31 PM Nihar Sahoo via Star-hp-l
>> <star-hp-l AT lists.bnl.gov> wrote:
>> Hi Tong,
>>
>> As discussed yesterday, probably we need to be careful not to change
>>
>> again these Model calculations in our preliminary plots. So I would
>> suggest crosschecking and confirming again from your side on this
>> model
>> calculation to show at HQ2022.
>>
>> Besides, I have the following comments on your last updated
>> presentation
>> slides (_1003.pdf).
>>
>> Slide11:
>> NN -> Nucleon-Nucleon (NN)
>> What is b_NN? You need to describe it.
>>
>> Slide13:
>> I think it would be good if you could put some texts mentioning the
>> reason for the shrinking of the uncertainty band compared to QM2022
>> and
>> also results up to smaller <Npart>. What do you think?
>>
>> Slide14:
>> _ what is "nMPI"? Do you need to mention it somewhere?
>> _ "More input needed in the next week" do you want to update
>> anything?
>>
>> Thank you
>> Nihar
>>
>> On 2022-10-04 06:11, Tong Liu wrote:
>>> HI Nihar,
>>>
>>> I uploaded a new version of the slides, please take a look. As for
>> the
>>> pt range in previous results, I decided to do some "subtraction"
>>> instead of "addition" by removing the word "isobar" from the text
>> on
>>> figure, so that it looks more like I'm referring to everyone.
>> Please
>>> let me know what you think about it. Also I'll try to push on the
>>> pythia MPI side, but I'm not very sure I'll be able to get
>> anywhere
>>> significant beyond where I am now. Let's assume this is the
>> message we
>>> are going to give, and I'll let you know if I dig up something.
>>>
>>> Tong Liu
>>> Ph.D. Student '2023
>>> Physics Dept., Yale University
>>>
>>> Tel: 203-435-2130
>>>
>>> On Mon, Oct 3, 2022 at 9:07 AM Nihar Sahoo
>> <nihar AT rcf.rhic.bnl.gov>
>>> wrote:
>>>
>>>> Hi Tong,
>>>>
>>>> Please find my reply inline.
>>>> And looking forward to seeing your updated presentation slides.
>>>>
>>>> On 2022-10-02 07:43, Tong Liu wrote:
>>>>> Hi Nihar,
>>>>>
>>>>> Thanks for your comments. Please find my responses below-- those
>>>> not
>>>>> mentioned are applied to my slides already. However I'd like to
>>>> take
>>>>> until Sunday night and hopefully make some more changes to them
>>>> before
>>>>> uploading again, since we already have a lot to discuss here.
>>>>>
>>>>> Title: good catch; I meant “high-pt”. One of the worst
>> places
>>>> to
>>>>> have a typo :p
>>>>> Slide#3:
>>>>>
>>>>> _Do you want to say something about right side plots? Any link
>> to
>>>> your
>>>>>
>>>>> analysis…please point out that.
>>>>> Here it’s just an introduction to high pt hadron as a proxy to
>>>> jet
>>>>> quenching effect. The plot I used is the Au+Au high-pt hadron
>> Raa,
>>>>> which is going to be used later as well; in the text I was
>> really
>>>>> trying to be general and not talk about any specific
>> measurement,
>>>> but
>>>>> I might talk about it orally. If you think it’s too much
>> though
>>>> I
>>>>> can take it off; but I’d say let’s wait till a first
>>>> rehearsal.
>>>>
>>>> OK. that's fine.
>>>>
>>>>> Also it might be a good idea to put this slide right after the
>>>> title
>>>>> slide?
>>>>> Slide#4:
>>>>>
>>>>> STAR TPC eta acceptance is |eta| < 1.4 (without iTPC)
>>>>>
>>>>> What acceptance you are quoting here?
>>>>> I'm pretty sure it's |eta|<1… Please see slide 4 in
>>>>>
>>>>
>>>
>>
> https://indico.cern.ch/event/689846/contributions/2947105/attachments/1635225/2608617/Yichang-ChiYang.pdf
>>>>> [1]
>>>>> Slide#6
>>>>>
>>>>> _Can you please remind me where do you get this "p+p
>> uncertainty"?
>>>>>
>>>>> That comes from this paper:STAR Phys. Rev. Lett. 91, 172302
>> (2003)
>>>>> Slide#10:
>>>>>
>>>>> It is important to mention for Au+Au, d+Au, and Cu+Cu, what pT
>>>> ranges
>>>>>
>>>>> were used?
>>>>>
>>>>> It’s also using 5.1-10 GeV, same as isobar. The statement at
>> the
>>>>> bottom of the graph was meant for all measurements, but
>> apparently
>>>> it
>>>>> was not clear enough. Any suggestions?
>>>>
>>>> I would add one bullet mentioning this.
>>>>
>>>>> Slide#12:
>>>>>
>>>>> _ you have now two models: I) HG-PYTHIA QM2022 preliminary and
>> II)
>>>> new
>>>>>
>>>>> results that you labeled as "X+X N_hard"
>>>>>
>>>>> AFAIK, the difference between I) and II) is due to choice of
>>>> N_hard
>>>>> and
>>>>>
>>>>> N_part . Is not that?
>>>>>
>>>>> But from your labels it seems for I) you used pT>5 GeV, and for
>>>> II)
>>>>>
>>>>> N_hard is used but all pT range.
>>>>>
>>>>> Is that true?
>>>>> _ Why your uncertainty band for I) QM2022 preliminary results
>> has
>>>> been
>>>>>
>>>>> changed? It looks wider band in your preliminary results.
>>>>> OK let me explain further here… what the HG-PYTHIA model does
>>>> is, it
>>>>> generates a Glauber-level collision, throw a Poisson dice and
>>>>> determine how many hard collisions each NN collision has
>> (Nhard).
>>>> Then
>>>>> it goes to PYTHIA and ask for a p+p collision with nMPI=Nhard
>>>> (yeah
>>>>> that part I don’t understand yet either); then all the tracks
>>>> from
>>>>> all the PYTHIA collisions are stacked together to be the
>> synthetic
>>>>> event. Here in the plot, both options categorized events into
>>>>> centralities with the “refmult” of this synthetic event, but
>>>> the
>>>>> “benchmark values” are calculated in different ways: in the
>>>>> “Nhard” option, the average Nhard in each centrality class
>> is
>>>>> compared to <Nhard> of pp collisions, while in the “Y_ch”
>>>> option,
>>>>> the invariant yield of 5 GeV+ tracks is used (<Ncoll> scaling is
>>>>> applied in both cases, of course). I didn’t use any <N_part>
>> in
>>>> this
>>>>> baseline beyond the x axis.
>>>>> As for the change to QM prelim, that one  was easy: I squeezed
>>>> much
>>>>> larger statistics out of the simulation. In fact this one is
>> still
>>>>> statistical error only, and I’ll try to get a crude
>> systematics
>>>> in
>>>>> the next week.
>>>>
>>>> Ok, I got it some extent now.
>>>>
>>>> Thank you
>>>> Nihar
>>>>>
>>>>> Slide#14:
>>>>>
>>>>> Do you have associated systematic uncertainty for <Ncoll> and
>>>> <Npart>
>>>>>
>>>>> scaled?
>>>>>
>>>>> The systematic uncertainty assigned to <Ncoll> and <Npart> by
>> the
>>>>> centrality group is VERY small, and I suspect they are
>> correlated
>>>>> between species, so they also largely cancel out.
>>>>>
>>>>> Tong Liu
>>>>> Ph.D. Student '2023
>>>>> Physics Dept., Yale University
>>>>>
>>>>> Tel: 203-435-2130
>>>>>
>>>>> On Sat, Oct 1, 2022 at 3:03 AM Nihar Sahoo via Star-hp-l
>>>>> <star-hp-l AT lists.bnl.gov> wrote:
>>>>>
>>>>>> Hello Tong,
>>>>>>
>>>>>> Please find my comments below  on your nice presentation
>> slides.
>>>>>>
>>>>>> Slide#1:
>>>>>> Title: System size dependence of pT hadron yield
>> modification…"
>>>>>> ->
>>>>>> "System size dependence of hadron yield suppression…" or
>>>> something
>>>>>> like
>>>>>> that
>>>>>> Here, "pT hadron yield modification" sounds awkward.
>>>>>>
>>>>>> Slide#3:
>>>>>> _Title: "…QGP probe" -> "…QGP Probe"
>>>>>> _"..lose energy to QGP" -> "… lose energy in QGP"
>>>>>> _"…RAA: comparison to p+p collisions" -> not quite right?
>>>> Define
>>>>>> RAA
>>>>>> using Au+Au and nuclear thickness function..
>>>>>> It is important for your previous bullet for Npart and Ncoll
>>>>>> _Do you want to say something about right side plots? Any link
>> to
>>>>>> your
>>>>>> analysis…please point out that.
>>>>>>
>>>>>> Slide#4:
>>>>>> STAR TPC eta acceptance is |eta| < 1.4 (without iTPC)
>>>>>> What acceptance you are quoting here?
>>>>>>
>>>>>> Slide#6
>>>>>> _Can you please remind me where do you get this "p+p
>>>> uncertainty"?
>>>>>>
>>>>>> Slide#8-9
>>>>>> I would make that blue box transparent such that the data
>> points
>>>> can
>>>>>> be
>>>>>> visible behind.
>>>>>>
>>>>>> Slide#10:
>>>>>> It is important to mention for Au+Au, d+Au, and Cu+Cu, what pT
>>>>>> ranges
>>>>>> were used?
>>>>>>
>>>>>> Slide#12:
>>>>>>
>>>>>> _ you have now two models: I) HG-PYTHIA QM2022 preliminary and
>>>> II)
>>>>>> new
>>>>>> results that you labeled as "X+X N_hard"
>>>>>> AFAIK, the difference between I) and II) is due to choice of
>>>> N_hard
>>>>>> and
>>>>>> N_part . Is not that?
>>>>>> But from your labels it seems for I) you used pT>5 GeV, and for
>>>> II)
>>>>>> N_hard is used but all pT range.
>>>>>> Is that true?
>>>>>>
>>>>>> _ Why your uncertainty band for I) QM2022 preliminary results
>> has
>>>>>> been
>>>>>> changed? It looks wider band in your preliminary results.
>>>>>>
>>>>>> Slide#14:
>>>>>> Do you have associated systematic uncertainty for <Ncoll> and
>>>>>> <Npart>
>>>>>> scaled?
>>>>>>
>>>>>> Cheers
>>>>>> Nihar
>>>>>>
>>>>>> On 2022-09-29 09:54, webmaster--- via Star-hp-l wrote:
>>>>>>> Dear Star-hp-l AT lists.bnl.gov members,
>>>>>>>
>>>>>>> Tong Liu (tong.liu AT yale.edu) has submitted a material for a
>>>>>> review,
>>>>>>> please
>>>>>>> have a look:
>>>>>>> https://drupal.star.bnl.gov/STAR/node/61208
>>>>>>>
>>>>>>> Deadline: 2022-10-11
>>>>>>> ---
>>>>>>> If you have any problems with the review process, please
>> contact
>>>>>>> webmaster AT 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
>>>>>
>>>>>
>>>>> Links:
>>>>> ------
>>>>> [1]
>>>>>
>>>>
>>>
>>
> https://indico.cern.ch/event/689846/contributions/2947105/attachments/1635225/2608617/Yichang-ChiYang.pdf
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--

Sooraj Radhakrishnan

Research Scientist,

Department of Physics

Kent State University

Kent, OH 44243

Physicist Postdoctoral Affiliate

Nuclear Science Division
Lawrence Berkeley National Lab
MS70R0319, One Cyclotron Road

Berkeley, CA 94720

Ph: 510-495-2473

Email: skradhakrishnan AT lbl.gov