STAR Flow, Chirality and Vorticity PWG

["Tang, Aihong" <aihong AT bnl.gov>]

Hi Yicheng,

I think it is a bit similar to the famous Wu-Yang-Lee experiment, but now it is strong decay in a magnetic field. 

The parity symmetry requires those decay daughters not make a net electric current, which correlates different rho decays. 

Any violation of that should be attributed to the local chirality imbalance (P-violation), so it is just another _expression_ of CME. ​

It seems that you may have missed my point, as I don't see how the point you mentioned above has anything to do with my question.   

I believe I phrased my question clearly, but to clarify once more --- and this will likely be my final attempt after asking twice already --- it is possible to generate rho_00 by conventional mechanisms, such as quarks being polarized by the strong magnetic field, without needing to invoke the LPV argument. If you're unfamiliar with this, it is discussed in many papers on rho_00.   So, how can all of the observed rho_00 be attributed to the CME ? 

Thanks,

Aihong

On Aug 14, 2024, at 3:53 PM, Feng, Yicheng <feng216 AT purdue.edu> wrote:

Hi Diyu and Aihong, 

I think your questions on spin alignment are related, so I put our reply in this single email. 

I think it is a bit similar to the famous Wu-Yang-Lee experiment, but now it is strong decay in a magnetic field. 

The parity symmetry requires those decay daughters not make a net electric current, which correlates different rho decays. 

Any violation of that should be attributed to the local chirality imbalance (P-violation), so it is just another _expression_ of CME. ​

For Diyu's question on event-by-event B field. 
I think the B direction and PP direction are mixed in your question.

In one event, let's say there are 3 directions: B, PP, SP.  

The |Bx|, |By| in this paper is basically a measurement w.r.t. B-direction, not a measurement w.r.t. PP, 

so we cannot say that PP feels a stronger B field than SP, nor PP is more correlated to B than SP. 

Central collisions don't have a SP, so it is out of the scope of this discussion.

In non-central collisions, the magnetic field should mainly come from the spectator protons, so B direction should be more correlated to SP than PP. 

In this sense, the signal w.r.t. SP should be still stronger than PP, and the relationship should be the projection factor. 

The algebra has been mentioned in the discussion. 

The formula below depends on what the physics root is. If the physics is CME, then it is along B, and Dg_SP = Dg_B <cos2(Psi_B-Psi_SP)>: 

Dg_SP = <cos(phi1+phi2-2Psi_SP)> = <cos(phi1+phi2-2Psi_B+2Psi_B-2Psi_SP)> ~ <cos(phi1+phi2-2Psi_B)><cos2(Psi_B-Psi_SP)> = Dg_B <cos2(Psi_B-Psi_SP)>

The correlation chain is: B fluctuates about SP, and PP fluctuates about SP, so 

Dg_PP = Dg_SP <cos2(Psi_SP-Psi_PP)> = Dg_B <cos2(Psi_B-Psi_SP)> <cos2(Psi_SP-Psi_PP)>

The fluctuation of B about SP <cos2(Psi_B-Psi_SP)> drops in our formulism.

Sincerely,

Yicheng for the PAs

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From: star-fcv-l-request AT lists.bnl.gov <star-fcv-l-request AT lists.bnl.gov> on behalf of "Shen, Diyu" <star-fcv-l AT lists.bnl.gov>
Sent: Wednesday, August 14, 2024 12:09 PM
To: STAR Flow, Chirality and Vorticity PWG <star-fcv-l AT lists.bnl.gov>
Subject: Re: [[Star-fcv-l] ] FCV PWG meeting on 14/Aug/2024 Wed. 9:30 AM EDT

 

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Hi Yicheng and all,

Regarding my question of whether the event-by-event B field is more correlated with PP or SP, I am referring to the Fig.2 of this paper:

<preview.png>

1201

PDF Document · 1.8 MB

It is clear that in most central collisions where there are no spectators the event-by-event B field is still significant, this is a very early paper, I don’t know if there was such a discussion in STAR, but I have concern of arguing event-by-event B field along/perpendicular to spectator plane.

Thanks,

Diyu

On Aug 14, 2024, at 23:31, Shen, Diyu (via star-fcv-l Mailing List) <star-fcv-l AT lists.bnl.gov> wrote:

Hi Yicheng and all,

This is our paper of spin alignment contribution to CME observables.

arxiv.org

<Outlook-aepj5srb.png>

Physics Letters B 839 (2023) 137777

It is very clear no matter what the quantization axis is the rho00 will contribute to OS pairs.  During the meeting it seems you are arguing decay products of different mesons are correlated if quantization axis is magnetic field.  I do not understand this point. In my opinion decay of different mesons are independent, what is the “global correlation” of resonance decay?  How can you demonstrate it in data?

Thanks,

Diyu

On Aug 14, 2024, at 21:27, Feng, Yicheng <feng216 AT purdue.edu> wrote:

Hi All, 

Please find my slides through the drupal link below: 

https://drupal.star.bnl.gov/STAR/system/files/Fcme20240812_v2.pdf

Sincerely,

Yicheng

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From: star-fcv-l-request AT lists.bnl.gov <star-fcv-l-request AT lists.bnl.gov> on behalf of Prithwish Tribedy <ptribedy AT rcf.rhic.bnl.gov>
Sent: Tuesday, August 13, 2024 8:54 PM
To: STAR Flow, Chirality and Vorticity PWG <star-fcv-l AT lists.bnl.gov>
Subject: [[Star-fcv-l] ] FCV PWG meeting on 14/Aug/2024 Wed. 9:30 AM EDT

 

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Dear All,

We are going to have our weekly FCV PWG meeting this Wednesday
(14/Aug/2024) at 9:30 AM EDT. If you wish to present, please let us
know. The agenda will be collected at:
https://nam04.safelinks.protection.outlook.com/?url="https%3A%2F%2Fdrupal.star.bnl.gov%2FSTAR%2Fblog%2Fjjiastar%2Fbulkcorr&data=05%7C02%7Cfeng216%40purdue.edu%7C01ad4525873d497cb3a208dcbbfbbf31%7C4130bd397c53419cb1e58758d6d63f21%7C0%7C0%7C638591937126690562%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C&sdata=1y42iv1CEGT5M4miiZ61VLdSyIkCx6eulHWBJBIk4Pc%3D&reserved=0

Please send us your slides by Tuesday. Zoom details are copied below.

Thanks and regards,
Prithwish, Zhenyu, and Subhash