STAR HardProbes PWG

[Dandan <shendandan AT mail.sdu.edu.cn>]

Hi lsaac and all，

Thank for your mention and Yi. I'm sorry I forgot to reply to this message. Today, I discussed the first point with Yi, and I will explain it after QM. On the second point: I have calculated the difference between integral p_T and integral centrality at 1.5σ.

Here is my new version slides of request preliminary. Please find it in the link: 

https://drupal.star.bnl.gov/STAR/system/files/Request_preliminary_Jpsi_polarization_0.pdf

After discussions with Rongrong, Barbara and Yi， my request preliminary made the following changes.

This slides undate conclusion, which are added “Hint non-trivial pt dependence”, and data in the figure do not changed.

The poster adds “Hint non-trivial pt dependence” in the conclusion in the same way. Poster can be found in the link：https://drupal.star.bnl.gov/STAR/system/files/Dandan_QM2023_v6.pdf

Best，

Dandan

发件人："Mooney, Isaac via Star-hp-l" <star-hp-l AT lists.bnl.gov>
发送日期：2023-09-01 08:50:20
收件人：STAR HardProbes PWG <star-hp-l AT lists.bnl.gov>
抄送人："Mooney, Isaac" <isaac.mooney AT yale.edu>,Yi Yang <yiyang0429 AT gmail.com>,Qian <yangqian2020 AT sdu.edu.cn>
主题：Re: [Star-hp-l] Request Preliminary: J/ψ polarization in Isobar data

Hi Dandan,

I was thinking the same thing as Yi on the two points I highlighted below. But we had a discussion just now and I agree that the first point could be addressed after QM and the second point is probably okay. 

As for the rest of the preliminary request slides, I am happy with them.

Thanks,

Isaac

On Aug 28, 2023, at 2:00 AM, Yi Yang via Star-hp-l <star-hp-l AT lists.bnl.gov> wrote:

- p9: I was thinking about what you explain about the difference in statistical errors between HX and CS. I still think that the statistical uncertainty should be the same in different frames. The argument you have is that the phase spaces are different, in CS you are limited to smaller phase spaces (Figure 2), so you have large uncertainty from the fit (to determine the polarization parameter). But (to me) it should be taken into account to the systematics uncertainty, in particular the polarization parameter extraction. This is the problem of the definition, not the statistics. As Zebo mentioned, if you have infinite statistics but you only have one phase space point (extreme case), you still can not determine the polarization. And it is due to the definition, not statistics (increasing statistics won't help). You can use a large statistics sample to study the effect, for example you can say in the CS frame, we will only be able to distinguish certain parameters in certain precision. 

We can leave it now for the preliminary, and we can discuss it in the publication phase. 

 - As we discussed in the meeting, the result in p9, the lambda_theta in CS frame looks very consistent with 0, but in p10, when you integrated all certaility, you see ~2 sigma effect. We might need to think of an explanation about it.