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Re: [Star-hp-l] Preliminary request for J/psi spin alignment measurement in Isobar data

From: tc88qy <tc88qy AT rcf.rhic.bnl.gov>
To: Yi Yang <yiyang0429 AT gmail.com>
Cc: STAR HardProbes PWG <star-hp-l AT lists.bnl.gov>
Subject: Re: [Star-hp-l] Preliminary request for J/psi spin alignment measurement in Isobar data
Date: Sat, 23 Sep 2023 00:49:38 +0800

Hi Yi,

We do have some of the discussion. Please find in this link:
https://drupal.star.bnl.gov/STAR/system/files/jpsiSpinAlignment_20230917.pdf
https://drupal.star.bnl.gov/STAR/system/files/jpsiSpinAlignment_20230920.pdf

Please find my reply inline.

On 2023-09-22 23:52, Yi Yang wrote:

Hi Qian,

I was traveling for the past two weeks, sorry for the late replies.
I missed some discussions, apologize if I asked something repeatedly.
- p9: Does the acceptance and efficiency depend on rho_00? Here you
assume rho_00 is 1/3, will it bias your results?

This has been studied in the first link. The results shows the impact is small.

- p10: what is the y-axis label "l-ract."?

It is "fraction". Since we only care about the relative shape. So I normalized the
total yield to 1.

- p11: could you please show the sizes of uncertainties from each
source, instead of just showing the sources?

This part has been shown at HP pwg meeting, which can be found in this link:
https://drupal.star.bnl.gov/STAR/system/files/jpsiSpinAlignment_20230914.pdf
If you want I can put it into the slides.

- p11: Any event plane uncertainty should be included here?

The event-plane resolution has been corrected in the final results.

- p13 and p14: If simply adding all the points from the left, I would
expect to have a smaller deviation from 0. Could you please remind me
why the systematics is much smaller in the 0-80% bin?

We sum over all data point according to statistical weighted average method. The results is consistent with
the 0-80% data point. As you can find in the second link Page 3.

- p15: legend: isobar -->ZrZr+RuRu

done

Cheers,
Yi

On Fri, Sep 22, 2023 at 4:38 AM tc88qy via Star-hp-l
<star-hp-l AT lists.bnl.gov> wrote:

Hello Yi and Isaac

Just a remind, that the SPIN2023 conference will start in 3 days.
Can you send out your comments?

Thanks
Qian Yang
On 2023-09-22 16:34, tc88qy via Star-hp-l wrote:

Hello Nihar,

Sure, we can have more details discussion after the conference.

Qian Yang

On 2023-09-22 15:10, Nihar Sahoo wrote:

Hello Qian,

Thank you for updating those figures.
After going through your slide16-17, I think we need to revisit

the

extraction of fitting parameter and its error again for final
publication. Please remind us on this point after the conference

to

have a discussion on it.

Cheers
Nihar

On 2023-09-22 12:13, tc88qy wrote:

Hello Nihar,

I have updated the plots. Thanks for your sign-off.

Qian Yang

On 2023-09-22 13:13, Nihar Sahoo wrote:

Hello Qian,

Could you include all your fitting plots like in SLide12 for

all

centralities in your preliminary request?
That probably we have not seen and we missed.
It is important for our future discussion after the conference.

https://drupal.star.bnl.gov/STAR/system/files/Preliminary_figures_request_1.pdf

Thank you
Nihar

On 2023-09-22 10:04, Nihar Sahoo via Star-hp-l wrote:

Hello Qina,

Please find my reply inline.

On 2023-09-21 19:52, tc88qy wrote:

Hello Nihar,

STAR released ZDC first-order EP results at QM. People may

ask do

we
have a comparison
between first-order EP and second-order EP. That the reason

we did

the
comparison.
We can keep in mind that they do have difference just as you

and

Subhash motioned.

I look at your preliminary request:

https://drupal.star.bnl.gov/STAR/system/files/Preliminary_figures_request_1.pdf

You have probably removed that comparison plots. Is not it?

Besides, your preliminary request looks fine to me.
With these, I sing off.

Thank you
Nihar

If you don't have further question, can I understand it as an

sign-off?

Hello Subhash
Thanks for pointing to the paper

Qian Yang

On 2023-09-21 16:40, Nihar Sahoo wrote:

Hello Qian,

Thank you addressing my comments. All your responses are

fine to

me.

One follow up on your this reply.

2.I just talking about the data, error bars can touch

each

other by
using "TPC 2nd order EP" and "ZDC 1st order EP".

Sorry, Not clear.

Actually, Do you have any physics expectation to the

comparison

if
the 1st order EP have such large error bars?

If you look at my earlier comment copied here. Probably, my
earlier
comment was not clear.

2. On Slide 4, My expectation that "TPC 2nd order EP"

and

"ZDC 1st
order EP" may give a bit different results. But you

quote

"Results are
consistent with each other due to large error bars in

first

order
measurement". It sounds like using different Detectors (

TPC

vs. EPD)
and EP order (1st vs 2nd) results are still consistent.

Is

that you
want to say?

What I want say is, if we use different detectors (central

vs.

forward
acceptance) and also different (1st vs 2nd) order EP to

calculate

your
J/psi spin alignment then do we expect the results would be

the

same
or not?
My expectation: it may not give the same because using TPC

and

ZDC
detector have different correlation to acceptance region.

And

also
different order EP could be another factor.
But you quote "Results are consistent ..."

Just to know your comment on it.

Thank you
Nihar

On 2023-09-21 13:00, tc88qy wrote:

Hello Nihar,
Please find my reply inline.

On 2023-09-20 18:16, Nihar Sahoo wrote:

Hello Qian,

Please find my reply inline.

On 2023-09-20 14:56, tc88qy wrote:

Hello Barbara and Nihar
I included 0-5% centrality to the first bin in the
preliminary
request plots. The results have been updated in the
preliminary
request plots. Please look at the it in this link:

https://drupal.star.bnl.gov/STAR/system/files/Preliminary_figures_request_1.pdf

Hi Nihar
1.Just as I mentioned in previous email. We should look

at a

centrality range with clear physics information.

How do you know what is _clear physics_?

we probably need to think about the physics information we

want

to look at.
In our case, it is the charm and anti-charm correlation

that

affecting by QGP.
In most the Au+Au analysis, STAR paper then talk about QGP

in a

centrality of 0-60% or 0-50%, just like the phi spin

alignment

paper
are carry out at 20-60%. 20-50% or 20-60% centrality is

what

people
usually look at for QGP related study.
In peripheral collision, the case could very different from

central
and semi-central collision.
I think it would be good to using 0-20%, 20-50% and 50-80%
centrality bins.

2.I just talking about the data, error bars can touch

each

other by
using "TPC 2nd order EP" and "ZDC 1st order EP".

Sorry, Not clear.

Actually, Do you have any physics expectation to the

comparison

if
the 1st order EP have such large error bars?

3. done
4. The rho_00 central value in 50-80% is on top of 1/3.

While

by
looking at the pT dependence of the same centrality,
every data points central value is above 1/3. This is
inconsistency and related to yield extraction method.
5. will done in the talk

Please include in your preliminary request also.

done

6. Please check in the preliminary request plot

Please find additional comment on your preliminary

request:

https://drupal.star.bnl.gov/STAR/system/files/Preliminary_figures_request_1.pdf

1) Slide13-14: "Centrality Integral" data point, the

plotting

style is
incorrect because of X-axis.
I suggest to use the style of plotting in Fig.2 of

Uplsilon PRL

paper.

https://journals.aps.org/prl/pdf/10.1103/PhysRevLett.130.112301 [1]

This is the first time I know that we have style

requirement for

Physics plots.
I have update it in the same link.

2) Slide 15: "global spin alignment signal mainly from the

pT

range 1-3 GeV/c"
Do you mean you only use 1-3 gev/c range only for

centrality

dependence plot like fig. in SLide13,14?
If so, why don't you consider 3-4 gev/c range?

In each plots, I updated it with a legend to mention the pT

and

y
range we used in the analysis.
And after discuss with fcv group, we decide not show the pT

dependence.

3) Do you have plan to show both Fig.1 and Fig,2 outside

as

STAR preliminary?
I am wondering because Fig.2 shows there may be a

centrality

dependence, other hand Fig.1 shows fluctuations across
centralities
and also contradicts the earlier.

Yes, we plan to show both. Fig 1. just show people the

signal

over centralities.
In figure 2, We do not say there is a centrality

dependence.

We emphasize the centrality range we selected.
0-20% with the largest J/psi regeneration probability.
20-50%, QGP with largest angle momentum or particle v2.
50-80%, a reference

Qian Yang

Thank you
Nihar

Regards,
Qian Yang

On 2023-09-20 15:51, Nihar Sahoo wrote:

Hello Qian,

My apologies, for my late response.
Please find my comments on your preliminary request.

1. On Slide3 "Centrality binning", I would prefer to use

0-20%,
20-40%, and 40-80% binning. Let me know what do you

think. As

is done
in Slide4 right side figure with STAR preliminary.
2. On Slide 4, My expectation that "TPC 2nd order EP"

and

"ZDC 1st
order EP" may give a bit different results. But you

quote

"Results are
consistent with each other due to large error bars in

first

order
measurement". It sounds like using different Detectors (

TPC

vs. EPD)
and EP order (1st vs 2nd) results are still consistent.

Is

that you
want to say?
3. Slide5 left fig: I think you need to include 0-20%

instead

of 5-20%
centrality for pT-dependence plot. Is not it? [same for
Slide7]
4. Slide5: "ρ00 systematic above 1/3 in pT dependence

study

for
50-80%…" -> But it looks all are consistent with 1/3

(dotted

line)
within uncertainty except 2-3 GeV/c pT bin (just ~1

sigma

difference).
Is not that?
5. SLide8: Please Include ALICE reference.
6. Please include also Physics message/conclusion on

Slide

6,7,8.

Thank you
Nihar

On 2023-09-20 11:39, Barbara Trzeciak via Star-hp-l

wrote:

Hi Qian,

I don't have strong preference about the 40, 50 or 60%,

you

can leave
it as you had, 20-50 and 50-80%.
The main point was about not excluding the 0-5% range.
So from my side it's fine. But please wait if conveners

have

any
comments on this.

Cheers,
Barbara

On Wed, 20 Sept 2023, 07:55 tc88qy,
<tc88qy AT rcf.rhic.bnl.gov> wrote:

Hi Barbara,

The last centrality bin will have large error bar as

shown

in my
binning study.
What about 50-80%, it will reduce the error bars.
I also checked the 50-80% <N_part> in Isobar, it is
comparable
with
60-80% <N_part> in Au+Au.

Qian Yang

On 2023-09-20 12:51, Barbara Trzeciak wrote:

Hi Qian,
that's also fine. My only worry is that you will have

large
uncertainty for the pT different rho00 in this bin.

But

you can

check.

Cheers,
Barbara

On Wed, 20 Sept 2023, 05:39 tc88qy,
<tc88qy AT rcf.rhic.bnl.gov>

wrote:

Hi Barbara,
I see your point. I agree to include 0-5% centrality

to

the
first
bin.
If we do 20-40% and 40-80% centrality, the last bin

do

gain
precisions.
But we probably need to think about the physics
information we

want

to
look at. In our case, it is the charm and anti-charm

correlation
that
affecting by QGP. In most the Au+Au analysis, STAR

paper

then

talk

about
QGP in a centrality of 0-60%, just like the phi spin

alignment

paper

are
carry out at 20-60%.
So, I suggest we do the binning of 0-20% , 20-60%

and

60-80%.
What do you think?

Qian Yang

On 2023-09-19 23:39, Barbara Trzeciak wrote:

Hi Qian,

thanks for point to the slides with additional

checks.

Regarding 0-5% centrality bin:
As ShinIch also commented, sometimes the most

central

bin is

remove

due to poor event plane resolution. However, in

this

case I

don't

see

the resolution being particularly bad, it's not so

much

worse

than

for

the mid-central case. If we have enough confidence

to

have this

point

in the centrality differential plot, I don't see a
reason why

not

to

include it when you integrate to wider centrality
ranges.
Regarding the other binning:
The reason for having 20-40% and 40-80% is that the

precision of

the

mid-central point is almost the same while the
peripheral bin

gains in

precision compare to the 50-80% centrality range.

Cheers,
Barbara

On Tue, 19 Sept 2023, 17:21 tc88qy,
<tc88qy AT rcf.rhic.bnl.gov>

wrote:

Hi Barbara,

I replied to the HP list for the comments I got

from

last HP
meeting.
Please find the details in this link:

https://drupal.star.bnl.gov/STAR/system/files/jpsiSpinAlignment_20230917.pdf

In terms of the binning, I am not sure the reason

of

20-40%

bin.

Qian Yang

On 2023-09-19 22:15, Barbara Trzeciak wrote:

Hi Qian,

I see that you consider three centrality classes

on

plots on

slides

14-16 - same as you presented last week.
As we discussed in more detail at the previous HP

meeting, it

looks a

bit weird (and I don't know what's the motivation

in

this

case)

that

you exclude 0-5% centrality bin.
I suggest having the first bin as 0-20%

centrality,

then

20-40%

and

40-80%.
Also, could you please prepare a comparison to

the

results

that

use

the first order event plane.

Cheers,
Barbara

On Mon, Sep 18, 2023 at 10:36 AM tc88qy via

Star-hp-l

<star-hp-l AT lists.bnl.gov> wrote:

Hello all,
Please find my preliminary plots request in link

below:

https://drupal.star.bnl.gov/STAR/system/files/Preliminary_figures_request_1.pdf

Qian Yang
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Links:
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[1] https://urldefense.com/v3/__https://journals.aps.org/prl/pdf/10.1103/PhysRevLett.130.112301__;!!P4SdNyxKAPE!Bo1U-unYExfI0stJt_qckE-irbv6Wvk2SrPjs-aAXatstFnjJ2Fyr2CsPrnRDe5egYKV0IU6RRLwtE_BePmAJQnTmK4i$

Re: [Star-hp-l] Preliminary request for J/psi spin alignment measurement in Isobar data , (continued)