STAR Flow, Chirality and Vorticity PWG

[Roy Lacey <roy.lacey AT stonybrook.edu>]

One last word on this issue;

The real question is why Fuqiang can accuse us of fraud when the evidence clearly shows that the near-side subtraction technique is inappropriate/wrong in this case.

One can not use the near-side method for this analysis because LCC alone can account for all of the non-flow. This has been a well-known fact for more than ten years.

Our rudimentary estimate of the non-flow via hydro confirms that the jet-driven non-flow has to be small as well. This limits the magnitude of the jet-driven systematic uncertainty relative to the actual signal measured.

I am sick and tired of Fuqiang's accusations of fraud - he did the same thing for our CME analysis and wasted months of our time and without penalty when he was proven wrong on all fronts. 

STAR should not enable this seemingly malicious behavior.

Roy

On Fri, Jan 21, 2022 at 12:32 PM Helen Caines via Star-fcv-l <star-fcv-l AT lists.bnl.gov> wrote:

I think about lot of what you are looking for is in the paper we published back in 2012

https://arxiv.org/pdf/1110.5800.pdf

Fig 8 shows the near-side yield as a function of Npart for 200 and 62.4

We also know from our Rcp BES paper that the relative yield of jet to bulk drops quickly below 62 since the Rcp goes >>1 at lower energies due to the push to higher pt from radial flow. If jet-like particles were dominating one would expect the Rcp to <=1 depending on the amount of quenching at each energy.

Helen

***********************

Yale University
Physics Dept. - Wright Lab.
PO Box 208120
New Haven, CT 06520
203-432-5831
***********************
she/her/hers
"Life is not about waiting for the storms to pass.
It's about learning how to dance in the rain." - Vivian Greene

On Jan 21, 2022, at 11:09 AM, Wang, Fuqiang via Star-fcv-l <star-fcv-l AT lists.bnl.gov> wrote:

Dear FCV conveners,

 

Roy said that the authors have “demonstrated that (i) all of the questions you [Fuqiang] raised had been addressed - expressly and unequivocally.”

I want to see the study of near-side jetlike correlations as function of centrality in Au+Au collisions at 200 GeV and at one of the lower energies (maybe 54 or 39 GeV).

 

Best regards,

Fuqiang

 

 

From: Starpapers-l <starpapers-l-bounces AT lists.bnl.gov> On Behalf Of Wang, Fuqiang via Starpapers-l
Sent: Thursday, January 20, 2022 11:12 AM
To: Roy Lacey <roy.lacey AT stonybrook.edu>; STAR Papers Discussion List <starpapers-l AT lists.bnl.gov>
Subject: Re: [Starpapers-l] New STAR paper ready for submission: Collision-system and beam-energy dependence of anisotropic flow fluctuations

 

Dear Colleagues,

 

STAR and CMS (and ALICE I believe) have used the near-side subtraction.

ATLAS and PHENIX did not do it.

At Wednesday’s FCV meeting, I expressed the strong opinion that the near-side correlation data should be looked at and considered in the systematic uncertainty estimate.

Another strong opinion was also expressed, from the ATLAS point of view, that the near-side subtraction should not be used.

 

Look, this is about systematic uncertainty assessment:

1)     The PA’s pick some approaches and refuse to consider others;

2)     I argue that all viable approaches should be considered, which would likely result in a more conservative systematic uncertainty.

Some others have also expressed the latter opinion at yesterday’s FCV meeting.

STAR decides to go along with 1).

This is a misinformed decision, to say the least.

 

Best regards,

Fuqiang

 

 

From: Roy Lacey <roy.lacey AT stonybrook.edu> 
Sent: Thursday, January 20, 2022 12:36 AM
To: Wang, Fuqiang <fqwang AT purdue.edu>; STAR Papers Discussion List <starpapers-l AT lists.bnl.gov>
Cc: Helen Caines <helen.caines AT yale.edu>
Subject: Re: [Starpapers-l] New STAR paper ready for submission: Collision-system and beam-energy dependence of anisotropic flow fluctuations

 

Fuqiang,

              In Wednesday's PWG  meeting, we demonstrated that (i) all of the questions you raised had been addressed - expressly and unequivocally, (ii) your proposed method of near-side subtraction is not just flawed. It is simply wrong.

                  One could say that your continued insistence on misrepresenting the scientific facts and the substance of our response is fraudulent, but I leave it for others to judge.

 Roy

 

On Wed, Jan 19, 2022 at 9:16 PM Wang, Fuqiang via Starpapers-l <starpapers-l AT lists.bnl.gov> wrote:

Dear Helen,

 

There is a claim in the paper: “the much smaller associated uncertainties.” I highly doubt it is true, but in any case all our statements should be supported by substances. I asked for studies supporting this claim (and gave a specific suggestion). I don’t see those studies or review of such studies. I conclude that this claim is made up without substances, so it is a fraudulent claim.

 

I did not say “fraudulent behavior” or “fraudulent approach.” The authors chose one particular approach of suppressing nonflow (eta gap 0.6) to arrive at a default result. I’m perfectly fine with it. I have trouble with the systematic uncertainty estimate. There are several viable approaches of estimating remaining nonflow; they should all be considered to arrive at an honest systematic uncertainty estimate. Don’t you agree? It is the PAs who refuse to consider all approaches, and STAR allows it.

 

Best regards,

Fuqiang

 

 

From: Starpapers-l <starpapers-l-bounces AT lists.bnl.gov> On Behalf Of Helen Caines via Starpapers-l
Sent: Wednesday, January 19, 2022 5:31 PM
To: STAR Papers Discussion List <starpapers-l AT lists.bnl.gov>
Subject: Re: [Starpapers-l] New STAR paper ready for submission: Collision-system and beam-energy dependence of anisotropic flow fluctuations

 

Dear Fuqiang,

 

We will remove your name from this paper as requested. 

 

Accusations of fraudulent behavior are very serious. We do not agree that it is at all appropriate in this case. 

 

We understand that there is a difference of opinion in how best to estimate the uncertainties. However, from the discussions so far there is no clear consensus that one approach is far superior to the other. The best treatment of non flow is still evolving as the field progresses.  

 

The PAs have taken one approach which is is clearly stated in the paper, as is how the uncertainty is estimated. 

 This is clearly not a fraudulent approach. 

 

Helen

 

***********************

Yale University
Physics Dept. - Wright Lab.
PO Box 208120
New Haven, CT 06520
203-432-5831
***********************
she/her/hers
"Life is not about waiting for the storms to pass.
It's about learning how to dance in the rain." - Vivian Greene

 

 

 

On Jan 18, 2022, at 10:33 AM, Wang, Fuqiang <fqwang AT purdue.edu> wrote:

 

Dear Helen, Rongrong, dear colleagues,

Up to this moment, I have not seen any study materials on jetlike modifications supporting “the much smaller associated uncertainties” claimed in the paper. Presumably the GPC would have requested and reviewed/discussed those materials. Such review discussions should not be controversial and can be readily made available, but I have not seen them despite of my multiple requests. Therefore, I have to conclude that those studies were actually not performed or revealed, and the paper has not been properly reviewed. In effect, the paper is making a fraudulent claim of “the much smaller associated uncertainties” without any substances. 

Given these serious issues, please remove my name from the author list of this paper. 

It is very strange that the PAs would not want to do such a study for their paper. Such study is not difficult or time consuming, and the PAs’ group is experienced in those studies (the group has done such a study for the small system flow). It still beats me, after so many repeated requests and after so many months, that such a basic study had not been performed for this paper, and the paper could actually get by with the STAR review process. 

I just looked at Hijing isobar simulation events we have at hand (we have been studying nonflow in isobar collisions and presented to CME focus group a few times). The first two plots below are examples of the \Delta\eta correlation functions per trigger in 80-75% and 30-25% centralities, respectively. I fit the central \Delta\eta peak by a Gaussian and plot the Gaussian area vs. the number of trigger particles (third plot below). The trigger and associated particles are all particles within |eta|<1 and 0.2-2 GeV/c so the number of triggers is just the event multiplicity. You can see that the number of associated particles per trigger increases from peripheral collisions to mid-central and central collisions by a factor of ~2. This is not surprising because jet quenching produces a lot more low pt particles. The peripheral subtraction method that the PAs used in their systematics study assumes this to be flat, and is clearly underestimating the effect. The jetlike modification can easily cause a factor of 2 difference. 

I also looked at v2 from Hijing which is all nonflow. The fourth plot below shows multiplicity scaled Nch*v2 vs. multiplicity (a \Delta\eta gap of 0.6 is applied.). If jetlike correlations are the same in peripheral and central collisions, then this quantity would be flat. Clearly it is not flat, indicating strong jetlike modifications. The flat dashed line would be the nonflow estimate from the peripheral subtraction method. The solid line would be the nonflow estimate trying to include jetlike modification effect by scaling the near-side peak area. Even that would significantly underestimate the nonflow v2, suggesting that the away-side nonflow effect is huge, which cannot be removed by a \Delta\eta gap.

Clearly there are strong nonflow effects in the v2 measurements from jetlike correlations and modifications. It would be a mistake to push out a paper without considering those nonflow effects! 

I will probably post an arXiv note on this, after I look into it a bit further and generate some Au+Au events. I think it is important that the science is made clear. 

<image002.png> <image004.png><image006.png><image008.png>

Best regards,

Fuqiang

 

 

From: Starpapers-l <starpapers-l-bounces AT lists.bnl.gov> On Behalf Of Helen Caines via Starpapers-l
Sent: Wednesday, January 12, 2022 12:17 PM
To: STAR Papers Discussion List <starpapers-l AT lists.bnl.gov>
Subject: [Starpapers-l] Fwd: New STAR paper ready for submission: Collision-system and beam-energy dependence of anisotropic flow fluctuations

 

 

Begin forwarded message:

 

From: Helen Caines <helen.caines AT yale.edu>

Subject: New STAR paper ready for submission: Collision-system and beam-energy dependence of anisotropic flow fluctuations

Date: January 12, 2022 at 12:16:29 PM EST

To: Haiyan Gao <hgao AT bnl.gov>, Yasuyuki Akiba <akiba AT bnl.gov>

Cc: Lijuan Ruan <ruan AT bnl.gov>

 

Dear Haiyan and Yasuyuki,

 

We are pleased to announce that STAR plans to submit the following paper for publication in one week. 

 

Intended Journal :   PRL

 

Title:  Collision-system and beam-energy dependence of anisotropic flow fluctuations

 

Abstract: Elliptic flow measurements from two-, four- and six-particle correlations are used to investigate flow fluctuations in collisions of U+U at sqrt(s_NN) = 193 GeV, Cu+Au at sqrt(s_NN) = 200 GeV andAu+Au spanning the range sqrt(s_NN) = 11.5 - 200 GeV. The measurements show a strong dependence of the flow fluctuations on collision centrality, a modest dependence on system size, and very little if any, dependence on particle species and beam energy. The results, when compared to similar

LHC measurements, viscous hydrodynamic calculations, and Glauber model eccentricities, indicate that initial-state-driven fluctuations predominate the flow fluctuations generated in the collisions studied.

 

Helen

 

***********************

Yale University
Physics Dept. - Wright Lab.
PO Box 208120
New Haven, CT 06520
203-432-5831
***********************
she/her/hers
"Life is not about waiting for the storms to pass.
It's about learning how to dance in the rain." - Vivian Greene

 

_______________________________________________
Starpapers-l mailing list
Starpapers-l AT lists.bnl.gov
https://lists.bnl.gov/mailman/listinfo/starpapers-l

_______________________________________________
Starpapers-l mailing list
Starpapers-l AT lists.bnl.gov
https://lists.bnl.gov/mailman/listinfo/starpapers-l
_______________________________________________
Star-fcv-l mailing list
Star-fcv-l AT lists.bnl.gov
https://lists.bnl.gov/mailman/listinfo/star-fcv-l

_______________________________________________
Star-fcv-l mailing list
Star-fcv-l AT lists.bnl.gov
https://lists.bnl.gov/mailman/listinfo/star-fcv-l