STAR Flow, Chirality and Vorticity PWG

[subhash <subhash AT rcf.rhic.bnl.gov>]

Dear Charles, Gavin,

Thanks for the modified abstract. I have no further comments and I sign 
off.

Regards,
Subhash

On 2024-11-09 07:12 AM, Robertson, Charles William wrote:
> Hi Subhash, Convenors,
>
>  The new version of the draft has been uploaded to the same place on
> drupal, and the new file is here
> https://drupal.star.bnl.gov/STAR/system/files/QM2025AbstractRobertsonWils_Merged_2.pdf
> [1]
>
>  For your comments:
>
>  Title: I would suggest something like: Measurement of Global, Local,
> and
> Helicity Spin Alignment of ϕ-Mesons in High Nuclear Collisions at
> RHIC
> (But in the abstract text you have to clarify what you mean by local)
>  Done
>
> I would suggest to remove l#2-5: "They are predicted .... physical
> mechanisms."
> l#5: "However, a significant ...strong force field []" --> We observed
> unexpectedly large ρ_00 values for ϕ(1020) mesons in the first phase
> of the
> RHIC Beam Energy Scan (BES-I) in Au+Au collisions. These values exceed
> conventional expectations based on global hyperon polarization induced
> by
> orbital angular momentum, suggesting the possible presence of a strong
> force
> field for ϕ mesons [].
>  We did this with more or less the same wording
>
> l#8-11: "Previous measurements ....decay daughter distributions" -->
> Previous
> ρ00 measurements use a 1D angular distribution in θ* (polar angle of
> the
> daughter kaon in the ϕ meson rest frame relative to the event plane).
> We
> will use both angular dimensions (theta* and \phistar), enabling
> off-diagonal
> element extraction with fewer assumptions about decay daughter
> distributions.
>  This is corrected to use beta, which is the correct variable for the
> 2D extraction, not phi star.
>
> l#11-15: "We wil present .... (BES-II)" --> We will present
> differential
> measurements of ϕ-meson ρ_00 and off-diagonal spin density matrix
> elements,
> using data from the second phase of RHIC BES (BES-II) in Au+Au
> collisions at
> √sNN = 7.7–19.6 GeV collected by STAR. Results will be shown as
> functions
> of rapidity (y), centrality, and transverse momentum (pT).
>  Done
>
> l#15-17: "Alongside, ... two from" --> Additionally, we will present
> differential helicity frame spin alignment results to test their
> predicted
> relation with global spin alignment.
>  Done
> l#18-20: "We will also present ... pair invariant mass" --> We will
> also
> present ρ_00 results using two alternative extraction methods: (i)
> ⟨cos2
> θ*⟩ and (ii) ⟨cos 2ϕ*⟩ (where ϕ* is the projection of θ*
> onto the
> transverse plane) as a function of the kaon pair invariant mass.
>  Done
>  l#21-22: I would suggest removing: "We report ... where applicable."
>  Portion about the revision has been removed
> l#23: To me the definition of local is not obvious here, I guess you
> are
> trying to follow the same convention as used in lambda polarization
> along
> beam axis, right?
>  Clarified the local alignment
>
>  Thanks,
>  -CW, on behalf of the PA's
>
> -------------------------
>
> From: star-fcv-l-request AT lists.bnl.gov
> <star-fcv-l-request AT lists.bnl.gov> on behalf of webmaster AT star.bnl.gov
> <webmaster AT star.bnl.gov>
> Sent: Wednesday, November 6, 2024 9:34 PM
> To: star-fcv-l AT lists.bnl.gov <star-fcv-l AT lists.bnl.gov>
> Subject: [[Star-fcv-l] ] STAR presentation by Charles Robertson for
> Quark Matter 2025 got commented by Subhash Singha
>
> ---- External Email: Use caution with attachments, links, or sharing
> data ----
>
> Dear star-fcv-l AT lists.bnl.gov members,
>
> Subhash Singha ( connectsubhash AT gmail.com ) has commented on a
> material
> originally submitted by Charles Robertson ( rober558 AT purdue.edu ) at
> https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdrupal.star.bnl.gov%2FSTAR%2Fpresentations%2FQuark-Matter-2025%2FPhi-Meson-Local-Global-and-Helicity-Spin-Alignment-STAR&data=05%7C02%7Crober558%40purdue.edu%7Cf9f2189d45d4421826c308dcfed4ca2e%7C4130bd397c53419cb1e58758d6d63f21%7C0%7C0%7C638665437100230692%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=TdiCtdzfOVA%2BesaSp%2FS1TGAJxdn7ZbZ0fUM0nivuW5o%3D&reserved=0
> [2]
>
> Comment:
> Dear PAs,
>
> Nice abstract. I have a few suggestions for your consideration:
>
> Title: I would suggest something like: Measurement of Global, Local,
> and
> Helicity Spin Alignment of ϕ-Mesons in High Nuclear Collisions at
> RHIC
> (But in the abstract text you have to clarify what you mean by local)
>
> I would suggest to remove l#2-5: "They are predicted .... physical
> mechanisms."
> l#5: "However, a significant ...strong force field []" --> We observed
> unexpectedly large ρ_00 values for ϕ(1020) mesons in the first phase
> of the
> RHIC Beam Energy Scan (BES-I) in Au+Au collisions. These values exceed
> conventional expectations based on global hyperon polarization induced
> by
> orbital angular momentum, suggesting the possible presence of a strong
> force
> field for ϕ mesons [].
>
> l#8-11: "Previous measurements ....decay daughter distributions" -->
> Previous
> ρ00 measurements use a 1D angular distribution in θ* (polar angle of
> the
> daughter kaon in the ϕ meson rest frame relative to the event plane).
> We
> will use both angular dimensions (theta* and \phistar), enabling
> off-diagonal
> element extraction with fewer assumptions about decay daughter
> distributions.
>
> l#11-15: "We wil present .... (BES-II)" --> We will present
> differential
> measurements of ϕ-meson ρ_00 and off-diagonal spin density matrix
> elements,
> using data from the second phase of RHIC BES (BES-II) in Au+Au
> collisions at
> √sNN = 7.7–19.6 GeV collected by STAR. Results will be shown as
> functions
> of rapidity (y), centrality, and transverse momentum (pT).
>
> l#15-17: "Alongside, ... two from" --> Additionally, we will present
> differential helicity frame spin alignment results to test their
> predicted
> relation with global spin alignment.
> l#18-20: "We will also present ... pair invariant mass" --> We will
> also
> present ρ_00 results using two alternative extraction methods: (i)
> ⟨cos2
> θ*⟩ and (ii) ⟨cos 2ϕ*⟩ (where ϕ* is the projection of θ*
> onto the
> transverse plane) as a function of the kaon pair invariant mass.
> l#21-22: I would suggest removing: "We report ... where applicable."
> l#23: To me the definition of local is not obvious here, I guess you
> are
> trying to follow the same convention as used in lambda polarization
> along
> beam axis, right?
>
> ---
> If you have any problems with the review process, please contact
> webmaster@https://nam04.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.star.bnl.gov%2F&data=05%7C02%7Crober558%40purdue.edu%7Cf9f2189d45d4421826c308dcfed4ca2e%7C4130bd397c53419cb1e58758d6d63f21%7C0%7C0%7C638665437100248245%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=kRhpAd1F3vp4ebLcm58UuJHKilCbtUz%2Fbtd%2F5A0TxQk%3D&reserved=0
> [3]
>
> Links:
> ------
> [1] 
> https://drupal.star.bnl.gov/STAR/system/files/QM2025AbstractRobertsonWils_Merged_2.pdf
> [2] 
> https://drupal.star.bnl.gov/STAR/presentations/Quark-Matter-2025/Phi-Meson-Local-Global-and-Helicity-Spin-Alignment-STAR
> [3] 
> https://urldefense.com/v3/__https://nam04.safelinks.protection.outlook.com/?url=http*3A*2F*2Fwww.star.bnl.gov*2F&amp;data=05*7C02*7Crober558*40purdue.edu*7Cf9f2189d45d4421826c308dcfed4ca2e*7C4130bd397c53419cb1e58758d6d63f21*7C0*7C0*7C638665437100248245*7CUnknown*7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ*3D*3D*7C0*7C*7C*7C&amp;sdata=kRhpAd1F3vp4ebLcm58UuJHKilCbtUz*2Fbtd*2F5A0TxQk*3D&amp;reserved=0__;JSUlJSUlJSUlJSUlJSUlJSUlJSUlJSU!!P4SdNyxKAPE!AS-LMyOSn1KHOYyytqCnaDhz00C1EVbRskU1QNw5wLedgdc38MtVmMakSZ5TcckLy5tTStd1FFlD6-a_GBisO6XJ1VsP$