STAR HardProbes PWG

[Tristan Protzman <tlp220 AT lehigh.edu>]

Hi Barbara,

I did take a look and don't see anything too strange in how the plots look, other than a large fluctuation in the R=0.2 average V2 between data set A and B.  I have a brief writeup of this here: Comparison of Jet V2 in Samples used for Ratio | The STAR experiment (bnl.gov)

Cheers,

Tristan 

On Thu, Mar 23, 2023 at 4:15 AM Barbara Trzeciak <barbara.trzeciak AT gmail.com> wrote:

Hi  Tristan,

Thanks for the answer. 

I agree that it might very well be a fluctuation that drives this v2 value and the uncertainty. Since we see this, my point was to just quickly check the v2 plot and the fit to make sure there's no trivial issue there.

And I don't think either that we should pick up a fluctuation that we like. But there are ways to minimize the effect of fluctuations that we can explore towards a paper. 

Cheers,

Barbara

On Wed, Mar 22, 2023 at 5:56 PM Tristan Protzman <tlp220 AT lehigh.edu> wrote:

Hi Barbara, Yi,

Thanks for the comments.  I've uploaded a new draft with the suggested changes.

As for your question Barbara, I agree that it is strange.  I will try to answer quickly now with what I think happened, and will follow up later with more details and plots.  To determine the values used for the ratio plots, I am fitting a constant to the pT range 10 < pT < 22.5 GeV/c (over all available points).  I believe what happened is on the particular random division of the data I did, the fluctuations were such that the points did actually fit a line better, thus reducing the error for the R=0.2 points.  While I did think this was strange, it also doesn't sit right with me to keep randomly dividing the data until I get a fluctuation which matches my expectations.  Perhaps there is a more robust way to do this, I would be happy to try to implement it.  

As I mentioned, I will follow up with more details and plots a bit later today.

Cheers,

Tristan 

On Wed, Mar 22, 2023 at 7:36 AM Yi Yang <yiyang AT ncku.edu.tw> wrote:

Hi Tristan,

Thanks a lot for the nice slides. I have some minor comments on version 2 for your consideration. 

  p3: Central events --> Central collision events 

  p5: I would put the title of this page as "STAR detector" and Event plane determination as one of the bullets. Please also indicate where is TPC since you mention it in the text (add a bullet for jet reconstruction). 

  

Cheers,

Yi

+++++++++++++++++++++++++++++++++++++++++++++++++++
Yi Yang, Professor
Department of Physics / 

Director of Science Education Center

National Cheng Kung University
Tainan, 701 Taiwan
E-Mail: yiyang AT ncku.edu.tw
Tel: +886-6-2757575 ext.65237
Fax: +886-6-2747995
Group Web: http://phys.ncku.edu.tw/~yiyang
+++++++++++++++++++++++++++++++++++++++++++++++++++

On Wed, Mar 22, 2023 at 6:05 AM Barbara Trzeciak via Star-hp-l <star-hp-l AT lists.bnl.gov> wrote:

Hi Tristan,

Thanks for the updated slides, they look good.

Remaining comments:

- s13: systematic uncertainties -> statistical uncertainties

And I have a question here as well, sorry for missing it earlier.

When you divide your sample in halves you should get consistent results within your stat. unc. However your central ratio values go quite down (within the unc,., but still).

This is because your R  = 0.2 jet v2 is larger - but what I don't understand is that if you decrease statistics by half you would expect an increase of the stat. unc. (which is the case for R = 0.4 and R = 0.6 whose v2 are consistent within 1 sigma and the stat. unc. increase), while the stat. unc. for R = 0.2 case decreases. 

Could you please have a look at this, and send the jet v2 plots where you have half of the statistics ?

- s16: geometry information, -> geometry information 

Cheers,

Barbara

On Tue, Mar 21, 2023 at 6:05 PM Tristan Protzman <tlp220 AT lehigh.edu> wrote:

Yes, they can be found here:  Isobar Jet V2 Preliminary Figures | The STAR experiment (bnl.gov)

On Tue, Mar 21, 2023 at 12:56 PM Nihar Sahoo <nihar AT rcf.rhic.bnl.gov> wrote:

Hello Tristan,

Thank you for addressing my comments.

Can you please point to your Drupal page putting all preliminary plots
and preliminary request slides?

Cheers
Nihar

On 2023-03-21 21:34, Tristan Protzman wrote:
> Hi Nihar, Barbara,
>
> Thank you for your careful review and comments.  I have also received
> feedback from the Lehigh group after my practice talk yesterday
> afternoon which has been addressed.  A new draft has been uploaded,
> find my comments below.
>
> Cheers,
> Tristan
>
> Nihar's Comments
>
> Slide-2:
>
> 1. "The contribution of each process to jet quenching is unknown "->
> But
> we do know in QGP radiative process dominates over collisional
> process.
> So this sentence probably needs to rephrase unless you want to say
> somethingelse.
> _Changed to suggest that measuring v2 can help distinguish between
> competing models of jet energy loss_
> 2. Can you give reference for collisional E_loss's  L dependence?
> 3. For radiative case L^2 dependence comes from BDMPS. So you need to
> give reference.
> _Both references added_
>
> SLide-3
> 1. In this plot, increase the X-axis title and label size (also for
> Y-axis). Not visible.
> _Changed_
> 2. "Central events show significant hadron suppression at high
> momentum"
> -> "    0-10% central events show significant hadron suppression at
> high
> momentum"
> _I would like to leave this as central, since all centralities show
> suppression and I would like to draw _
> 3. You need to mention what are <Ncoll> and sigma_inel^NN and their
> values used for this result?
> _This plot was shown at QM22 by Tong without those values, I will work
> with Tong to find what was used and have them ready in backup at a
> minimum_
>
> SLide-4
>
> 1. "Semi-central collisions produce an approximately elliptical QGP"
> ->
> "Semi-central collision produces a elliptical geometry of the QGP
> medium"
> _I would like to leave approximately, since it is important to
> remember that the higher order fluctuations drive it away from
> elliptical_
> 2.  "To use familiar language, we will report this as 𝑣2, despite
> jet
> quenching being being distinct mechanism from flow" Not sure what you
> want to say here.
> _Changed to "_Though the language is the same, high 𝑝_T 𝑣_2 is
> driven by different effects than low 𝑝_T flow"
> 3. I think you need to introduce what is v2 as 2nd order anisotropy in
> this slide?
> _Added._
>
> Slide-6
> 1. X-axis title: pT^reco -> "pT^trak;
> _Changed_
> 2. X-axis: increase title and label size; put unit
> _Changed_
> 3. Y-axis: increase title and label size
> _Changed_
> 4. You need to mention before or in this slide what is pT?
> _Changed first occurrence _
> 5. "No strong momentum dependence observed "  -> "No transverse
> momentum
> dependence of v_{2} observed at high-p_{T}"
> _Changed_
>
> Slide-7
> 1. "Measuring high 𝑝T charged hadron 𝑣2 gives us a connection to
> flow
> measurements " Not sure what you want to say? Why only "high-pT
> charged
> hadron v2 gives connection to flow"? Please rephrase
> _Added explicate reference to low pT flow, drawing the connection that
> there is going to be a transition from the flow dominated v2 to
> quenching dominated flow_
> 2. "…with resolutions …"  -> "…with resolution (R)…" here you
> can
> introduce jet R.
> _Added_
> 3. Give STAR paper's reference to this upper v2 plot.
> _I don't believe this result has been published yet_
>
> Slide-9:
>
> 1. "2 GeV" -> "2 GeV/c"
> _Added_
> 2. "The event is clustered into jets with the anti-𝑘T algorithm" ->
> You
> have mentioned already in the above sentence. Drop this bullet.
> _I am making it clear that the event is clustered twice_
> 3. "Δ𝑅 < R_resolution "  you need to find a better way to write
> this.
> What is R_resolution?
> _Clarified with formula for \Delta R_
> 4. First subbullet of last bullet _expression_: you need to mention what
> are pT^measured, rho(phi), A, etc?
> _Added_
>
> SLide-10:
>
> 1. Title: "Combinatorial Jet Quenching" sounds awkward. Please
> rephrase
> this. Something like "Combinatorial jet contribution"
> 2.   Put this slide in backup. If somebody asks then show. Otherwise
> you
> don't need to speak on this test.
> _Changed and moved to backup_
>
> SLide-11,12,13:
>         1. Please follow the same suggestion on this fig from Slide-6
> _Changed_
>         2. "Small, non-zero R=0.2 anti-𝑘T jet 𝑣2 in isobar
> collisions at STAR "
> -> "Non-zero jet v_{2} is observed for R=0.2 in isobar collisions"
> (same
> for SLide12)
> _Changed_
>         3. "Like charged particle …" -> "Like inclusive charged
> particle…"
> _Changed_
>         4. "No obvious R dependence!" -> "No jet R dependence of v_{2}
> is
> observed"  (Not sure why it is "Obvious"?)
> _I would like to keep this as there is no obvious effect looking at
> the plot, and on the next slide we quantify this_
>
> Slide-14:
> 1. Please follow  the same suggestion on this fig from Slide-6
> _Done_
> 2. "To remove correlations by comparing the same partons, the
> numerator
> and denominator are separate sets of events"
>         Can you please rephrase this sentence to make it more clear?
>
> _Removed, and I will spend time explaining this clearly in the talk _
>
> Barbara's Comments
>
> - s2: add references related to the coll. and radiative processes
> _Added_
> - s3: the last bullet - please follow the status of Isaac's poster
> _Will do!_
> - s4: define v2. I would rephrase the last bullet. The mechanisms
> causing v2 are different at low and high pT, but it's still v2
> observable. Maybe something along the line: "non-zero v2 at high pT
> due to jet quenching"
> _Rephrased to "_Though the language is the same, high 𝑝_T 𝑣_2 is
> driven by different effects than low 𝑝_T flow"
> - s5: change title of the slide, e.g. Event Plane Reconstruction
> _Done_
> - s5: before run 18 -> before 2018
> _Changed_
> - s5: since you don't show STAR or don't have more details on the used
> detector for the jet reconstruction, I suggest to add at least
> information that we have the full azimuthal coverage.
> _Changed, showing STAR as well now.  I couldn't make a graphic I liked
> demonstrating the EPD usage_
> - s6: No strong momentum -> No strong p_T
> _Changed_
> - s8: you can remove "Effect demonstrated with a toy model", this
> information is below.
> _Removed_
> - s11-13: as you go from slide 11 to 13, add: R=0.2 then R=0.2 and 0.4
> then  R=0.2, 0.4 and 0.6, to your first bullet
> _ADded_
> - s12: "No obvious R dependence!" - make it bold or in colour
> _Bolded_
> - s13: Elrage x and y-axis title size and the text font size of the
> plot.
> _Changed_
> - s15: appears consistent -> consistent. You can add "in overlapping
> p_T region"
> _Added_
> - s15: you should be a bit careful here. You compare v2 to ALICE 2.76
> TeV results. Then you show R_AA from ALICE for 5.02 TeV for charged
> jets, and compare it to our isobar single particle R_AA, with
> different pT coverages. The discussion may look a bit messy and
> far-fetched. I think it's fine that  we ask questions, maybe I would
> remove "Maybe – Both systems show similar 𝑅AA for mid-central
> even". Please try to think a bit on this, how you can make a smooth
> but brief story from slides 15-17 and reduce material you're showing
> there. Some suggestions below.
> _I removed that line, and found a more accurate comparison from ALICE
> to use instead.  I also removed the claim of similar RAA, since that
> wasn't accurate looking at the correct comparison _
> - s16: I would suggest removing this or partially merge it with the
> next slide. You already have many slides, and it would be good to
> focus more on presenting our results.
> _Agreed, removed_
> - s18-19: I would remove it - you advertise Isaac's poster and if he
> shows one then anyway we won't have physics results yet. It's fine to
> mention it in the conclusions, as you have now.  And your talk is
> 15min so it might not fit time wise.
> _Removed for now, I'm following Isaac's status as well.  I had a
> little extra time in my practice talk so I'll keep track of what
> happens._
> - Add the STAR logo on your slides.
> _Added_
>
> On Fri, Mar 17, 2023 at 12:06 PM Barbara Trzeciak
> <barbara.trzeciak AT gmail.com> wrote:
>
>> Hi Tristan,
>>
>> please find below my comments to your nice slides.
>>
>> - s2: add references related to the coll. and radiative processes
>> - s3: the last bullet - please follow the status of Isaac's poster
>> - s4: define v2. I would rephrase the last bullet. The mechanisms
>> causing v2 are different at low and high pT, but it's still v2
>> observable. Maybe something along the line: "non-zero v2 at high pT
>> due to jet quenching"
>> - s5: change title of the slide, e.g. Event Plane Reconstruction
>> - s5: before run 18 -> before 2018
>> - s5: since you don't show STAR or don't have more details on the
>> used detector for the jet reconstruction, I suggest to add at least
>> information that we have the full azimuthal coverage.
>> - s6: No strong momentum -> No strong p_T
>> - s8: you can remove "Effect demonstrated with a toy model", this
>> information is below.
>> - s11-13: as you go from slide 11 to 13, add: R=0.2 then R=0.2 and
>> 0.4 then  R=0.2, 0.4 and 0.6, to your first bullet
>> - s12: "No obvious R dependence!" - make it bold or in colour
>> - s13: Elrage x and y-axis title size and the text font size of the
>> plot.
>> - s15: appears consistent -> consistent. You can add "in overlapping
>> p_T region"
>> - s15: you should be a bit careful here. You compare v2 to ALICE
>> 2.76 TeV results. Then you show R_AA from ALICE for 5.02 TeV for
>> charged jets, and compare it to our isobar single particle R_AA,
>> with different pT coverages. The discussion may look a bit messy and
>> far-fetched. I think it's fine that  we ask questions, maybe I would
>> remove "Maybe – Both systems show similar 𝑅AA for mid-central
>> even". Please try to think a bit on this, how you can make a smooth
>> but brief story from slides 15-17 and reduce material you're showing
>> there. Some suggestions below.
>> - s16: I would suggest removing this or partially merge it with the
>> next slide. You already have many slides, and it would be good to
>> focus more on presenting our results.
>> - s18-19: I would remove it - you advertise Isaac's poster and if he
>> shows one then anyway we won't have physics results yet. It's fine
>> to mention it in the conclusions, as you have now.  And your talk is
>> 15min so it might not fit time wise.
>> - Add the STAR logo on your slides.
>>
>> Cheers,
>> Barbara
>>
>> On Fri, Mar 17, 2023 at 12:48 PM Nihar Sahoo via Star-hp-l
>> <star-hp-l AT lists.bnl.gov> wrote:
>>
>>> Hello Tristan,
>>>
>>> Please find my comments on your nice presentation slides.
>>> _________
>>> General comment/suggestion to all HP2023 and DIS2023 presenters:
>>> 1. Please make a Drupal page for all your preliminary plots and
>>> provide
>>> us the link.
>>> If you have already done that, please send us the link.
>>>
>>> 2. While preparing your analysis plots for "STAR preliminary"
>>> request,
>>> please follow the guidance 1-7:
>>> https://drupal.star.bnl.gov/STAR/pwg/common/Preliminary-figures
>>> It saves our time.
>>> _________
>>>
>>> Please increase your slide number font size and use different
>>> color. It
>>> is invisible.
>>>
>>> Slide-2:
>>>
>>> 1. "The contribution of each process to jet quenching is unknown
>>> "-> But
>>> we do know in QGP radiative process dominates over collisional
>>> process.
>>> So this sentence probably needs to rephrase unless you want to say
>>>
>>> somethingelse.
>>> 2. Can you give reference for collisional E_loss's  L dependence?
>>> 3. For radiative case L^2 dependence comes from BDMPS. So you need
>>> to
>>> give reference.
>>>
>>> SLide-3
>>> 1. In this plot, increase the X-axis title and label size (also
>>> for
>>> Y-axis). Not visible.
>>> 2. "Central events show significant hadron suppression at high
>>> momentum"
>>> -> "    0-10% central events show significant hadron suppression
>>> at high
>>> momentum"
>>> 3. You need to mention what are <Ncoll> and sigma_inel^NN and
>>> their
>>> values used for this result?
>>>
>>> SLide-4
>>>
>>> 1. "Semi-central collisions produce an approximately elliptical
>>> QGP" ->
>>> "Semi-central collision produces a elliptical geometry of the QGP
>>> medium"
>>> 2.  "To use familiar language, we will report this as 𝑣2,
>>> despite jet
>>> quenching being being distinct mechanism from flow" Not sure what
>>> you
>>> want to say here.
>>> 3. I think you need to introduce what is v2 as 2nd order
>>> anisotropy in
>>> this slide?
>>>
>>> Slide-6
>>> 1. X-axis title: pT^reco -> "pT^trak;
>>> 2. X-axis: increase title and label size; put unit
>>> 3. Y-axis: increase title and label size
>>> 4. You need to mention before or in this slide what is pT?
>>> 5. "No strong momentum dependence observed "  -> "No transverse
>>> momentum
>>> dependence of v_{2} observed at high-p_{T}"
>>>
>>> Slide-7
>>> 1. "Measuring high 𝑝T charged hadron 𝑣2 gives us a
>>> connection to flow
>>> measurements " Not sure what you want to say? Why only "high-pT
>>> charged
>>> hadron v2 gives connection to flow"? Please rephrase
>>> 2. "…with resolutions …"  -> "…with resolution (R)…" here
>>> you can
>>> introduce jet R.
>>> 3. Give STAR paper's reference to this upper v2 plot.
>>>
>>> Slide-9:
>>>
>>> 1. "2 GeV" -> "2 GeV/c"
>>> 2. "The event is clustered into jets with the anti-𝑘T
>>> algorithm" -> You
>>> have mentioned already in the above sentence. Drop this bullet.
>>> 3. "Δ𝑅 < R_resolution "  you need to find a better way to
>>> write this.
>>> What is R_resolution?
>>> 4. First subbullet of last bullet _expression_: you need to mention
>>> what
>>> are pT^measured, rho(phi), A, etc?
>>>
>>> SLide-10:
>>>
>>> 1. Title: "Combinatorial Jet Quenching" sounds awkward. Please
>>> rephrase
>>> this. Something like "Combinatorial jet contribution"
>>> 2.   Put this slide in backup. If somebody asks then show.
>>> Otherwise you
>>> don't need to speak on this test.
>>>
>>> SLide-11,12,13:
>>> 1. Please follow the same suggestion on this fig from
>>> Slide-6
>>> 2. "Small, non-zero R=0.2 anti-𝑘T jet 𝑣2 in isobar
>>> collisions at STAR "
>>> -> "Non-zero jet v_{2} is observed for R=0.2 in isobar collisions"
>>> (same
>>> for SLide12)
>>> 3. "Like charged particle …" -> "Like inclusive charged
>>> particle…"
>>> 4. "No obvious R dependence!" -> "No jet R dependence of
>>> v_{2} is
>>> observed"  (Not sure why it is "Obvious"?)
>>>
>>> Slide-14:
>>> 1. Please follow  the same suggestion on this fig from Slide-6
>>> 2. "To remove correlations by comparing the same partons, the
>>> numerator
>>> and denominator are separate sets of events"
>>> Can you please rephrase this sentence to make it more
>>> clear?
>>>
>>> Cheers
>>> Nihar
>>>
>>> On 2023-03-17 10:45, Tristan Protzman via Star-hp-l wrote:
>>>> Hi All,
>>>>
>>>> There are still a few supporting figures I am remaking, clearly
>>> marked
>>>> as such.  These should be done in the next day or two at the
>>> latest,
>>>> and I will share when I have updated them.  The text and message
>>> of
>>>> those slides however is complete.
>>>>
>>>> Cheers,
>>>> Tristan
>>>>
>>>> On Fri, Mar 17, 2023 at 1:13 AM webmaster--- via Star-hp-l
>>>> <star-hp-l AT lists.bnl.gov> wrote:
>>>>
>>>>> Dear Star-hp-l AT lists.bnl.gov members,
>>>>>
>>>>> Tristan Protzman (tlp220 AT lehigh.edu) has submitted a material
>>> for a
>>>>> review,
>>>>> please have a look:
>>>>> https://drupal.star.bnl.gov/STAR/node/63006
>>>>>
>>>>> Deadline: 2023-03-26
>>>>> ---
>>>>> 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
>>> _______________________________________________
>>> 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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