STAR Flow, Chirality and Vorticity PWG

[ShinIchi Esumi <esumi.shinichi.gn AT u.tsukuba.ac.jp>]

Dear Rishabh (and Zuowen)
Thank you, I agree with you to go with the tack-wise phi-weighting, that is 
reasonable for your case. 

If you do the event-wise q-vector re-centering including the width 
correction, 
as you see in the following formula, you could even correct for the 2nd order 
moment in the non-flatness. Even if it is done without width correction, the 
1st 
oder moment should mostly be removed, so I think you might still have some 
problems in the re-centering procedure as it seems to be the case for the 
Zuowen’s slide from today (as he still seems to do the track-wise 
re-centering, 
which does not really make much sense to me), while LiKe’s correction seems 
to be OK. 

Qx' = ( Qx - mean(Qx) ) / width(Qx) 
Qy' = ( Qy - mean(Qy) ) / width(Qy) 

where, you can take mean(Qx) = <Qx>, width(Qx) = RMS of Qx, 
which is the mean and root mean square (or sigma equivalent for 
gaussian distribution) of Qx distribution for a given event class, that 
you like to calibrate. The same sets for Qy as well. 
Best regards, ShinIchi

> On Mar 30, 2022, at 22:43, rishabh <rishabh AT rcf.rhic.bnl.gov> wrote:
> 
> Dear ShinIchi,
> 
> Thank you so much for your email. I tried recentering the Q-vector 
> event-wise but still could not see a significant flattening of the event 
> plane angle. However, trackwise phi-weight correction was able to visibly 
> flatten the event plane distribution. Please find attached the slides 
> comparing the two methods of flattening the event plane distribution in 
> Au+Au collisions at √sNN = 54.4 GeV.
> So for my analysis, I am going ahead with the phi-weight correction.
> 
> Thanks and regards,
> Rishabh Sharma
> 
> 
> 
> On 2022-03-16 15:20, ShinIchi Esumi via Star-fcv-l wrote:
>> Dear Rishabh
>> I’m questioning the same thing to everyone yesterday in the special
>> pwg session,
>> it looks like you also have the similar problem in your re-centering
>> calibration, as we
>> still see about a half of the 1st moment of the non-flatness even
>> after the re-centering
>> calibration in your page 8, which tells me there is some problem in
>> the method. You
>> could look at the Priyanshi’s slide page 7, where we only see the
>> higher order contributions
>> than 1st order moments in a remaining non-flatness after the
>> re-centering calibration,
>> that is what is supposed to be, although the formula in the page 6 has
>> some issues.
>> So please make sure your re-centering correction is OK or not. It is
>> flat after the final
>> Fourier shift correction, so that the final results might still be OK,
>> but it would be better
>> to do it right. In stead of re-centering the q-vector, which should be
>> done in event-wise,
>> one can do an inverse weighting factor correction (track-wise) with
>> measured azimuthal
>> distribution. You can go back to the famous "flow bible" from Sergei
>> and Art in '96.
>> Best regards, ShinIchi
>>> 2022/03/14 3:16、subhash via Star-fcv-l <star-fcv-l AT lists.bnl.gov>のメール:
>>> Dear All,
>>> We will hold an additional FCV meeting this Tuesday, March 15, at 9:30 am 
>>> EST. This is a special meeting to accommodate some QM talk/posters for 
>>> which we have not received the request for preliminary. We would request 
>>> you to make a short presentation following:
>>> https://drupal.star.bnl.gov/STAR/system/files/Prelim_Request_template.pdf
>>> Since the QM is in a few weeks from now, it will be too late for us to 
>>> review and sign off your analysis if you can't present. Thanks for your 
>>> understanding.
>>> Best regards,
>>> Jiangyong, Prithwish and Subhash
>>> The tentative agenda can be found below:
>>> https://drupal.star.bnl.gov/STAR/blog/jjiastar/bulkcorr
>>> (Special Meeting for QM-approval) March 15, 2022:
>>> 1. Joey Adams -- lambda polarization
>>> 2. Gavin Wilks -- phi spin alignment
>>> 3. Shuai Zhou -- PID v2 BES
>>> 4. Diyu Shen -- charge dependent v1
>>> 5. Aditya Prasad -- charge dependent v1
>>> 6. Eddie Duckworth -- net proton v1
>>> 7. Niseem Magdy -- flow momentum correlation
>>> We shall use the FCV zoom link:
>>> https://urldefense.com/v3/__https://stonybrook.zoom.us/j/95735410810?pwd=M2JRZDBDSng4MG5SYmx6dlppYXhLZz09__;!!P4SdNyxKAPE!UXhP_DS8ys-TdWPw0_Vm4ATdCQdbWUfil5xQC2X14Niv1NnkB5575iHyZ29jG4Z4AVeuU8wc$
>>> Meeting ID: 957 3541 0810
>>> Passcode: 486227
>>> _______________________________________________
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>>> https://lists.bnl.gov/mailman/listinfo/star-fcv-l
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> <Recentering vs phi-weight.pdf>