STAR Flow, Chirality and Vorticity PWG

["Liu, Xiaoyu" <liu.6566 AT buckeyemail.osu.edu>]

Hello Prithwish,

Thanks for your comments and suggestions. I modified my slides and upload them under the same link: https://drupal.star.bnl.gov/STAR/presentations/dnp-2020/vn-measurement-auau-sqrtsnn-27-gev-event-plane-detector-star-1

Thanks,
Xiaoyu

---

From: Star-fcv-l <star-fcv-l-bounces AT lists.bnl.gov> on behalf of Prithwish Tribedy via Star-fcv-l <star-fcv-l AT lists.bnl.gov>
Sent: Friday, October 23, 2020 7:47 PM
To: STAR Flow, Chirality and Vorticity PWG <star-fcv-l AT lists.bnl.gov>
Subject: Re: [Star-fcv-l] STAR presentation by Xiaoyu Liu for DNP 2020 submitted for review

 

Hello Xiaoyu,
   Please consider the following comments for nice slides -- with these
included I sign off.

General comment:
I wonder if it's ok to just say "v1" instead of "vn" everywhere.

slide #2:
"Extracting flow from" --> "Flow measurement using"

slide#3:
"detector consist" --> "detector that consists"
"EPD acceptance" --> "EPD acceptance (2.1<|η|<5.1)"

If you are thinking about vertex then you can write below the figure:

"EPD acceptance is 2.1<|η|<5.1 but depends on the position of collision
vertex"

In order to make what you refer to as "fraction" I think you have to say
"Although the number of particles in not counted directly"
-->
"Although the number of particles hitting a tile is not counted
directly"

slide #4:
"they come from physics"
-->
"they depend on incident particle distribution"

slide #4:
The line starting with "Multi-MIP peaks" is kind of repeating what is
already said on this slide above -- but I leave this to you.

slide#4, figure:
I don't what's the best way to label these figures, maybe "STAR
performance" or "STAR preliminary" -- I would try one of those and get
suggestions from Takafumi.


slide#5:
I would start this slide by saying
"We divide η and φ-acceptance into ** and ** no of bins
respectively"

slide#5:
You have introduced Ψ1 on this slide which is not defined. You have
write the details of how Ψ1 was estimated.

Add a bullet:
"We will consider the relative angle of a hit w.r.to first order event
plane Ψ1 in the event"

slide#5 figure:
Add a caption: "Averaged nMIP distribution for a single η-φ bin"

slide#6 figure:
Δφ is not defined, if it is φ-Ψ1 then I would just write so or define it
somewhere.

slide#6:
"to get the dN/dφ:" --> "to get:"

slide#7, the last line:
I would assume you will add more details about event plane -- there you
can also mention about how event plane resolution was estimated.

slide#7, right figure:
This definitely needs more labels, like:
  "Au+Au 27 GeV", "STAR Performance"

If you have confusion and you don't intend to show any data I suggest
you get rid of slide#7. But then move bullet #4 to page 6 and add:
  "with this v1 can be estimated by fitting Fourier decomposition"


slide#8:
"All the primary vertex (PV) are at the original point"
-->
"Primary vertex (PV) position is set to Vx,Vy,Vz=(0,0,0)"

slide#9:
please add inside all plots
"Au+Au 27 GeV, UrQMD"

slide#9:
"limit EPD resolution"
-->
"limited EPD resolution"

slide#10:
In the outlook you can add "We plan to apply this method on data and
measure v1(η) at forward η"


Best,
Prithwish







On 2020-10-23 17:27, Liu, Xiaoyu via Star-fcv-l wrote:
> Hello Shinichi,
>
>  Yes, it is what I did with the UrQMD + EPD Fast Simulator study as
> shown in P9. It shows that the nMIP fitting method is able to count
> the number of particles properly (flow measurement is essentially
> counting dN/dphi).
>
>  I will consider the ADC cut in the GSTAR study, it is a very good
> point and thank you for the suggestion!
>
>  If you are okay with my DNP slides, could you please sign off my talk
> so it can be sent to STAR talk?
>
>  Thanks,
>  Xiaoyu
>
> -------------------------
>
> From: Star-fcv-l <star-fcv-l-bounces AT lists.bnl.gov> on behalf of
> ShinIchi Esumi via Star-fcv-l <star-fcv-l AT lists.bnl.gov>
> Sent: Friday, October 23, 2020 12:37 AM
> To: STAR Flow, Chirality and Vorticity PWG <star-fcv-l AT lists.bnl.gov>
> Subject: Re: [Star-fcv-l] STAR presentation by Xiaoyu Liu for DNP 2020
> submitted for review
>
> Dear Xiaoyu
> Thank you very much for the replacement of the figures.
>
> About the ADC cut, since you are ignoring amplitude information in the
> geant
> simulation just to count the number of particle per tile in the
> simulation, while
> you are effectively excluding pedestal noise and small ADC part below
> nMip<0.3
> etc in your experimental fitting method. So I just wanted to make sure
> you are not
> counting particle, if the ADC is quite small in your simulation, this
> is to make it
> as same as the experimental treatment.
>
> Since there is no reason why not to believe the ADC distribution in
> the simulation,
> therefore I was thinking this would be a good test ground for your
> nMip fitting to
> see how well you can count the number of particle by using the ADC
> distribution,
> which you might have already done with the fast Epd simulator, but
> this provides
> the more realistic ADC distribution coming from the dE/dx and photon
> statistics
> with the true geometry including BG hits in the geant simulation,
> where we could
> even include electronics noise to make reasonable pedestal peak, if we
> like to,
> where we know the truth and measured ADC.
>
> However your earlier test with UrQMD and fast simulator might include
> already
> the most of effects, though. Do I understand you correctly for your
> fast simulator
> with UrQMD, you overlay the extracted “measured” single MIP ADC
> distributions
> according to the number of tracks in a tile and then apply your nMip
> fitting to
> decompose the average number of track from the overlaid ADC
> distribution using
> the same single shape, which should give the same answer in principle
> by
> definition? This is what you are showing in p9 for your DNP talk?
> Best regards, ShinIchi
>
>> On Oct 23, 2020, at 7:46, Liu, Xiaoyu <liu.6566 AT buckeyemail.osu.edu>
> wrote:
>>
>> Hello Shinichi,
>>
>> Thanks for your suggestions. I updated my DNP slides with the new
> UrQMD plots (P9: 16 variable eta bins instead of 10 even eta bins) and
> the new version can be found at the same link:
> https://urldefense.com/v3/__https://drupal.star.bnl.gov/STAR/presentations/dnp-2020/vn-measurement-auau-sqrtsnn-27-gev-event-plane-detector-star-1__;!!KGKeukY!iKVEEHuNtXLuV0-0rSjZyf03Az7r3Z7cvjJDVlcnem5EyFvehk9xHAI2rqgfK9PvGkwA7wVyqEjl$
> [1]
>>
>>
>> For the v1 focus meeting, here is my slides:
> https://urldefense.com/v3/__https://drupal.star.bnl.gov/STAR/system/files/v1_meeting_102020_0.pdf__;!!KGKeukY!iKVEEHuNtXLuV0-0rSjZyf03Az7r3Z7cvjJDVlcnem5EyFvehk9xHAI2rqgfK9PvGkwA7x0vfjo9$
> [2]
>> If you are asking about the comparison between dN/deta of the
> simulated EPD hits (blue points on P5) and the dN/deta in the EPD
> acceptance extracted from the nMIP distribution with the real data,
> then I don't have it but I can make one later.
>>
>> I didn't use any ADC cut and I am not sure if it is needed. Even the
> ADC is very small, the signal is still created by some particle
> hitting the EPD tile therefore it should be counted. The small value
> is just due to the Landau fluctuation.
>>
>> I am not sure if I understand your last suggestion. Do you mean for
> each EPD tile, I can measure the number of primary particles
> (generated particles) hitting the tile and the number of "simulated
> particles" (EPD hits after going through the STAR material simulation)
> hitting the tile? What do you want to learn from it?
>>
>> Thanks,
>> Xiaoyu
>> From: Star-fcv-l <star-fcv-l-bounces AT lists.bnl.gov> on behalf of
> ShinIchi Esumi via Star-fcv-l <star-fcv-l AT lists.bnl.gov>
>> Sent: Wednesday, October 21, 2020 10:34 PM
>> To: STAR Flow, Chirality and Vorticity PWG
> <star-fcv-l AT lists.bnl.gov>
>> Subject: Re: [Star-fcv-l] STAR presentation by Xiaoyu Liu for DNP
> 2020 submitted for review
>>
>> Dear Xiaoyu
>> Thank you, that makes sense. This would mean we should not plot the
> results
>> with too small eta bins even for the input values to be compared
> with output values.
>> On the other hand, in the real event we do have quite a large
> z-vertex variation,
>> so eta average of each tile in each event are different, so one
> could still plot a little
>> finer bins in eta, if we like to, so we need to think about the
> optimal size of the
>> eta bin. I’m fine with your nice talk for DNP.
>> Best regards, ShinIchi
>>
>> PS : So the v1 vs eta in UrQMD and our data are quite different,
> which could be
>> reasonable, because of the poor description of spectators. Do you
> also have a
>> comparison of dN/deta between them?
>>
>> PPS : Sorry to ask you additional questions on your another
> presentation in v1
>> focus meeting yesterday, where you were just binary counting hits in
> each tile of
>> EPD to get measured v1 in MC, which is indeed reasonable, but did
> you exclude
>> hits below the value of 0.5*ADC for one mip, that need to be applied
> after
>> integrating all hits ADC values per tile in each HI event?
>>
>> Since you do have 2 ADC distributions for each tile and for both one
> mip (one
>> particle event) and multi-mips (overlaid many single events)
> including landau
>> and photon statistical fluctuation in addition to the real increase
> of the number
>> of particles between the two, therefore you could also apply your
> nMip fitting
>> method to see how well you can reconstruct the true “increase
> of” average
>> number of particle per tile in the MC, which is a kind of good test
> ground of
>> your approach and would also gives us the systematic error as well.
> You might
>> need to have some constrained fitting of these two simultaneously,
> where they
>> would have some common parameters in the function or do the fitting
> of the
>> multi-mip data with a convoluted "data" function from the single-mip
> distribution.
>>
>>> On Oct 22, 2020, at 1:44, Liu, Xiaoyu
> <liu.6566 AT buckeyemail.osu.edu> wrote:
>>>
>>> Hello Shinichi,
>>>
>>> Attached are the UrQMD + EPD fast simulator study with 16 variable
> eta bins (corresponding to 16 EPD rings). The black points and red
> points are almost on top of each other. So the discrepancy at large
> |eta| on my slide 5 is indeed due to the fact that the innermost ring
> covers two eta bins.
>>>
>>> Please let me know if you have any other suggestions or comments.
>>>
>>> Thanks,
>>> Xiaoyu
>>> From: Liu, Xiaoyu <liu.6566 AT buckeyemail.osu.edu>
>>> Sent: Sunday, October 18, 2020 8:07 PM
>>> To: STAR Flow, Chirality and Vorticity PWG
> <star-fcv-l AT lists.bnl.gov>; ShinIchi Esumi
> <esumi.shinichi.gn AT u.tsukuba.ac.jp>
>>> Subject: Re: [Star-fcv-l] STAR presentation by Xiaoyu Liu for DNP
> 2020 submitted for review
>>>
>>> Hello Shinichi,
>>>
>>> Thank you for your comments and sorry I didn't show the results at
> recent BulkCorr meetings. As you mentioned, for this talk, I just want
> to focus on introducing the new method and the v1, v2 plots are indeed
> unnecessary for this purpose so I deleted them.
>>>
>>> About the UrQMD study, I used the full Au+Au UrQMD events, not the
> particle gun if it is what you are asking. And they are just UrQMD
> events w/o going through any simulation for the STAR materials.
>>>
>>> I believe the discrepancy in large |𝜂| is due to the fact that
> the inner-most ring covers two largest 𝜂 bins therefore EPD cannot
> tell exactly which 𝜂 bin the hit belongs to. So v1_EPDhit
> (4.8<|𝜂 |<5.1) = v1_EPDhit (4.5<|𝜂 |<4.8) and they are all
> between v1_track (4.8<|𝜂 |<5.1) and v1_track (4.5<|𝜂 |<4.8). As
> for the bin 4.2<|𝜂 |<4.5, part of it falls on ring 1 and part of it
> falls on ring 2 so the v1_EPDhit(4.2<|𝜂 |<4.5) will be pulled
> either towards the bin on the left or the bin on the right therefore
> v1_EPDhit(4.2<|𝜂 |<4.5) is smaller than v1_track (4.2<|𝜂 |<4.5)
> which is the peak of v1. In other words, if I plot the same plot with
> the x-axis bins being the 16 EPD rings instead of 10 even 𝜂 bins in
> [2.1,5.1], the red points and the black points are expected to be on
> top of each other. I can make the plot and show you later.
>>>
>>> Sorry again for not discussing the results at BulkCorr earlier.
> Hope it will be okay if I only show the UrQMD results in this talk. I
> can present the UrQMD study in this week's FCV meeting if needed.
>>>
>>> I uploaded the second version under the same link:
> https://urldefense.com/v3/__https://drupal.star.bnl.gov/STAR/presentations/dnp-2020/vn-measurement-auau-sqrtsnn-27-gev-event-plane-detector-star-1__;!!KGKeukY!iKVEEHuNtXLuV0-0rSjZyf03Az7r3Z7cvjJDVlcnem5EyFvehk9xHAI2rqgfK9PvGkwA7wVyqEjl$
> [1]
>>>
>>> Please let me know if you have any other comments or suggestions.
>>>
>>> Thanks,
>>> Xiaoyu
>>> From: Liu, Xiaoyu <liu.6566 AT buckeyemail.osu.edu>
>>> Sent: Sunday, October 18, 2020 7:32 PM
>>> To: STAR Flow, Chirality and Vorticity PWG
> <star-fcv-l AT lists.bnl.gov>; ShinIchi Esumi
> <esumi.shinichi.gn AT u.tsukuba.ac.jp>
>>> Subject: Re: [Star-fcv-l] STAR presentation by Xiaoyu Liu for DNP
> 2020 submitted for review
>>>
>>> Hello Jiangyong,
>>>
>>> Thank you for your comments, I implemented most of them except:
>>>
>>> P3: I did use a random point on the tile to determine the \eta of a
> hit EPD tile.
>>>
>>> P5: I changed the "the number of 1-, 2-, k-...MIP events per
> collision" to "the fraction....". The reason why I didn't use
> "probability" is that it is only the probability when we fit the
> dN/dnMIP of one tile, in which case the integral of the dN/dnMIP
> distribution over nMIP is 1. However, if we look at the dN/dnMIP of
> several tiles then the integral of the distribution will be larger
> than 1 and the sum of the 1, 2, 3, 4-MIP weights might be larger than
> 1 too and the word "probability" can be misleading. Then I realized
> the word "number" can be equally misleading since people would expect
> the number of events to be integers. Therefore, I chose "fraction" and
> hopefully it is less confusing.
>>>
>>> P9: The data points are not mirrored around y=0, they do look very
> similar though.
>>>
>>> Besides, I decided to delete the v1 before the resolution
> correction with the real data as Shinichi suggested since I want to
> focus on the new method and these plots are not essential for this
> purpose.
>>>
>>> I uploaded the second version to the same link:
> https://urldefense.com/v3/__https://drupal.star.bnl.gov/STAR/presentations/dnp-2020/vn-measurement-auau-sqrtsnn-27-gev-event-plane-detector-star-1__;!!KGKeukY!iKVEEHuNtXLuV0-0rSjZyf03Az7r3Z7cvjJDVlcnem5EyFvehk9xHAI2rqgfK9PvGkwA7wVyqEjl$
> [1]
>>>
>>> Please let me know if you have any other comments or suggestions.
>>>
>>> Thanks,
>>> Xiaoyu
>>>
>>>
>>> From: Star-fcv-l <star-fcv-l-bounces AT lists.bnl.gov> on behalf of
> ShinIchi Esumi via Star-fcv-l <star-fcv-l AT lists.bnl.gov>
>>> Sent: Saturday, October 17, 2020 11:54 PM
>>> To: STAR Flow, Chirality and Vorticity PWG
> <star-fcv-l AT lists.bnl.gov>
>>> Subject: Re: [Star-fcv-l] STAR presentation by Xiaoyu Liu for DNP
> 2020 submitted for review
>>>
>>> Dear Xiaoyu
>>>
>>> I could sign off your nice talk, but you have not discussed this in
> the
>>> PWG yet, so it would be nice that you could have shown us before.
>>>
>>> P7-8 : The statistical errors are invisible, but do you know why
> the difference
>>> between track(pure sim) and hit(including geant) is suddenly
> increasing at
>>> |eta|>4. Are they a strong detector effect from a large dE/dx from
> spectator?
>>> You use the true R.P. angle for both cases, is this geant
> simulation done
>>> taking a full AuAu event of UrQMD or taking a single track from the
> UrQMD
>>> event one by one?
>>>
>>> P9-10 : Do you like your data plots to be approved as preliminary
> even with
>>> the uncorrected data? (for E.P. resolution and BG and detector
> effects)
>>> If you insist to show these, I would at least label them more
> clearly that this
>>> is uncorrected for many possible other effects, not just for R.P.
> resolution)
>>> If you like to explain your analysis methods in detail, you would
> not need to
>>> use the experimental data, but can be done more with UrQMD data. It
> seems
>>> we do see a strong spectator contributions in both v1 and v2 (and
> most-likely
>>> in dN/deta distribution as well) in data, but you can not really
> defend what
>>> this is just with uncorrected data, so I wonder what we can say
> with these
>>> plots.
>>>
>>> Best regards, ShinIchi
>>>
>>>> On Oct 18, 2020, at 10:55, Jiangyong Jia via Star-fcv-l
> <star-fcv-l AT lists.bnl.gov> wrote:
>>>>
>>>> Hi, xiaoyu,
>>>>
>>>> Here is my comments for sign off
>>>> cheers,
>>>> Jiangyong
>>>>
>>>> P1: please add "for the STAR Collaboration" and only keep your
> name
>>>>
>>>> P2: For outline consider avoiding technical terms such as "nMIP"
> and StEpdFastSim in
>>>>
>>>> P4: I would swap the order the two sub-bullet of the nMIP
>>>>
>>>> P5: Fit to extract "the probability of 1-2..k-MIP events" in bin j
>>>>
>>>> P6: please indicate the AuAu 27 GeV on this figure and also other
> figures where appropriate.
>>>> resolution correction --> correct for the event plane resolution
>>>>
>>>> P7: StEpdFastSim--> EPD fast simulation
>>>> same format as in the STAR offline data.
>>>>
>>>> a random point on the tile--> do you mean the center of the tile?
>>>>
>>>> P8: ring one--> the inner-most ring
>>>>  to correct for the measurement-->to account for residual detector
> effects
>>>>
>>>> The plots have been symmetrized around y=0, if so please indicate
> that
>>>>
>>>>
>>>> P10: please add some statement on this slide
>>>>
>>>> Plots on P8-P10 should have proper x- and y-axis labels
>>>>
>>>> P11: we developed a new method
>>>>
>>>>
>>>>
>>>> On 10/15/20 11:53 AM, webmaster--- via Star-fcv-l wrote:
>>>>> Dear star-fcv-l AT lists.bnl.gov
>>>>>  members,
>>>>>
>>>>> Xiaoyu Liu (
>>>>> liu.6566 AT osu.edu
>>>>> ) has submitted a material for a review, please
>>>>> have a look:
>>>>>
>>>>>
> https://urldefense.com/v3/__https://drupal.star.bnl.gov/STAR/node/52381__;!!KGKeukY!iKVEEHuNtXLuV0-0rSjZyf03Az7r3Z7cvjJDVlcnem5EyFvehk9xHAI2rqgfK9PvGkwA79SUGDt9$
> [3]
>>>>>
>>>>>
>>>>> ---
>>>>> If you have any problems with the review process, please contact
>
>>>>>
>>>>> webmaster AT www.star.bnl.gov
>>>>>
>>>>> _______________________________________________
>>>>> Star-fcv-l mailing list
>>>>>
>>>>> Star-fcv-l AT lists.bnl.gov
>>>>>
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> [4]
>>>>
>>>> _______________________________________________
>>>> Star-fcv-l mailing list
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> [4]
>>>
>>> <Picture1.pdf>
>
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>
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> Links:
> ------
> [1]
> https://urldefense.com/v3/__https://drupal.star.bnl.gov/STAR/presentations/dnp-2020/vn-measurement-auau-sqrtsnn-27-gev-event-plane-detector-star-1__;!!KGKeukY!iKVEEHuNtXLuV0-0rSjZyf03Az7r3Z7cvjJDVlcnem5EyFvehk9xHAI2rqgfK9PvGkwA7wVyqEjl$
> [2]
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> [3]
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