STAR HardProbes PWG

[Nihar Sahoo <nihar AT rcf.rhic.bnl.gov>]

Hi Youqi,

Please find my remaining question and comments inline.


On 2022-09-26 21:52, Youqi Song wrote:
> Hi Nihar,
>
> Thanks for the comments. Here are the updated slides
> https://drupal.star.bnl.gov/STAR/system/files/prelim_request_092622.pdf
>
> Yes, we can discuss the issue with smearing response after HQ.
>
> As for the tracking uncertainty, it might be difficult to try
> increasing it by 4%, since we are using official embedding and can't
> add tracks back.
Not sure, if I understand your procedure correctly, can you inform how 
do you implement then -4% in embedding?

> The ratio plot shown is MultiFold/RooUnfold, so I'm not sure what else
> I can label the y-axis to be. Maybe it's more clear now that I
> combined the ratio plot with the main plot of fig 1 in slide 15.

Ok, I understand now, I was thinking about the uncertainty band. But it 
is ok.and your plot looks nice now on slide#15.

Can you please also lower y- axis for plots in slide#20 like in slide15?

Looking forward to seeing your HQ presentation draft.

Cheers
Nihar

> Best,
> Youqi
>
> On Mon, Sep 26, 2022 at 8:05 AM Nihar Sahoo <nihar AT rcf.rhic.bnl.gov>
> wrote:
>
> > Hello Youqi,
> >
> > Please find my reply and queries inline.
> >
> > On 2022-09-25 23:02, Youqi Song wrote:
> > > Hi Nihar,
> > >
> > > Thanks for the feedback. I updated the slides here:
> https://drupal.star.bnl.gov/STAR/system/files/prelim_request_092522.pdf
> > > Response to unnumbered comments:
> > >
> > > Yes, I have three MCs, Herwig, Pythia8 and Pythia6, but what I did
> > > earlier was just to use Pythia6 for the *misses*, I still did
> > > unfolding with each of the different MC prior shapes. (Now the
> > plots I
> > > updated on Friday have both the misses and the unfolded parts with
> > > different priors). I plotted the fully corrected distributions
> > with
> > > the different priors together with other sources of sys
> > uncertainty in
> > > backup slide 1, and I just added a backup slide 2 with just the
> > > distributions due to prior shape variation.
> >
> > Ok, that's fine.
> > > Ok, I've added a slide after slide 15 to show the error breakdown.
> >
> > I like this comparison plot that is in Slide#16. It looks like at
> > this
> > stage both Multifold and RooUnfold give roughly the same
> > uncertainties.
> > But we need to go through some other systematic uncertainties (like
> > you
> > mentioned below) in future after HQ conf.
> > > For detector and generator level pT shape smearing, I think the
> > idea
> > > is to add some smearing to the response matrix itself. Maybe
> > others
> > > can correct me if I'm wrong.
> > Not sure if I understand this correctly, this needs a discussion.
> > Could
> > you please bring this topic up in your next presentation?
> > But for HQ, I think it is Ok, the systematic uncertainties you have
> > for
> > STAR preliminary.
> >
> > > Response to numbered comments:
> > >
> > > 1. For the detector response systematics, there are hadronic
> > > correction, tower scale and tracking efficiency variation.
> > > For hadronic correction, I see how it makes sense to vary in data
> > as
> > > well, but I learned that Raghav and Isaac didn't vary data for
> > their
> > > analyses, so I decided to go with how they did it. Also, I tried
> > > varying data as well, but it didn't have a large effect. See the
> > > comparison plot I added in slide 12.
> >
> > Good that you checked this for Hadronic correction.
> >
> > > For tower scale and tracking efficiency, I am not sure how we
> > would
> > > vary data. Right now I decreased the tracking efficiency in Geant
> > by
> > > 4%, and kept data the same. Do you mean that we should drop 4%
> > tracks
> > > in data for this variation as well?
> >
> > No, we don't change anything in the data. We can only change in the
> > tracking efficiency from embedding.
> > You mentioned that you only decreased 4%. Have you considered also
> > increasing 4% in your systematic uncertainties ? Just to confirm.
> >
> > > 2. Great, I updated the figure in the slide.
> >
> > Good, Can you please lower your y-axis scale (say -0.01) so that all
> > the
> > markers can be seen properly, particularly at large M region?
> > (in a plot, all data points should be presented/shown clearly)
> >
> > > 3. The star markers are MultiFold mass distributions divided by
> > > RooUnfold mass, so I'm not sure why we want a different style
> > marker?
> >
> > Suggesting because ratio star marker no need to be the same with
> > Multifold marker style. just for cosmetic.
> >
> > > The error bands are my unfolding systematics and RooUnfold
> > unfolding
> > > systematics added in quadrature, and then divided by RooUnfold
> > mass
> > > distribution.
> >
> > Can you please label your Y-axis accordingly without labeling as
> > "Ratio
> > with RooUnfold"?
> > It is not clear what you have written above. Is not it?
> > Please put pT range, "STAR Preliminary", and other info like your
> > slide#19.
> >
> > > 4. Great, agreed :)
> > >
> > > 5. I updated the legend to include "Detroit tune". I'm not sure we
> > > want to push for the q vs g separation physics message. Maybe
> > Helen
> > > and Raghav can say more about this, but my understanding is that
> > the
> > > quark and gluon jets can have similar fragmentation patterns at
> > 200
> > > GeV and there can be ambiguity regarding e.g. if you want to call
> > a
> > > jet initiated from g->qqbar splitting a quark jet or a gluon jet,
> > so
> > > instead it might be more interesting to treat the jets with
> > different
> > > M and Q as having different fragmentation patterns.
> > Ok, that makes sense to me.
> >
> > Cheers
> > Nihar
> >
> > > Best,
> > > Youqi
> > >
> > > On Sun, Sep 25, 2022 at 8:23 AM Nihar Sahoo
> > <nihar AT rcf.rhic.bnl.gov>
> > > wrote:
> > >
> > > > Hello Youqi,
> > > >
> > > > Thank you for your update and this information.
> > > >
> > > > I have the following comment and questions on your new updated
> > > > results
> > > > (plots) and also your notes.
> > > >
> > > > > Regarding systematics,
> > > > > - You might have noticed that the systematic errors for
> > multifold
> > > > have
> > > > > gone up by a bit. This is because I realized that before, when
> > > > doing
> > > > > herwig and pythia8 shape variations, I was using pythia6 mass
> > > > > distribution for the misses. Now I changed it so that the misses
> > > > > contribution
> > > > > for prior shape variation is also weighted by the mass ratio of
> > > > herwig
> > > > > (pythia8) over pythia6.
> > > >
> > > > Good that you found out this.
> > > > If I understand correctly, you have three MCs: Herwig, Pythia8,
> > and
> > > > Pythia6. You used each of these MC mass distributions for the
> > mass
> > > > shape
> > > > variation for sys uncertainties. Earlier, you used Pythia6 for
> > all
> > > > these
> > > > cases, but now you corrected it with their respective mass
> > shapes.
> > > > Is
> > > > that correct?
> > > > Could you show (include in your backup) us those mass
> > distribution
> > > > variations using these three different MC priors? Curious to see
> > the
> > > > difference due to different fragmentations in the mass
> > distribution.
> > > > > - After talking with Isaac, I learned that unfolding systematics
> > > > due to
> > > > > variation of iteration number and variation of prior shape were
> > > > treated
> > > > > as correlated in previous analyses, while I originally had these
> > > > added
> > > > > in quadrature. Now I also treat them as correlated by just
> > taking
> > > > the
> > > > > largest contribution to the unfolding systematic as the overall
> > > > > unfolding systematic, and add it in quadrature with detector
> > > > > systematics.
> > > >
> > > > Could you please separate out I) statistical uncertainty, II)
> > > > Correlated
> > > > Sys, and III) Uncorrelated Sys in your plot ( using Style2 in
> > > > slide#16)
> > > > without adding in quadrature? Please use a smaller marker size to
> > > > see
> > > > the stat. Error bar (even if it is small).
> > > >
> > > > > - Regarding the question whether there's anything still missing
> > > > that's
> > > > > raised during the meeting yesterday, I forgot to mention that we
> > > > > haven't included detector and generator level pT shape smearing.
> > > > This
> > > > > is included in Raghav's and Isaac's analyses because they did 1D
> > > > > reweighting, but we are not sure if it should be included for
> > > > > multidimensional unfolding.
> > > >
> > > > Hmm, Is not it that the total detector effects (tracking
> > efficiency
> > > > and
> > > > pT smearing) are considered using this multifold while you create
> > > > something like the response matrix? What am I missing here?
> > > >
> > > > Comments on your slide#12 (from this email preliminary templet
> > > > slides)
> > > >
> > > > 1. Slide#12: As you have mentioned, you have varied only in the
> > > > embedding, not in the data. General practice is to vary in the
> > data.
> > > > But
> > > > not sure if that will be accurately translated to the variation
> > in
> > > > the
> > > > data. It is interesting. i) Then how do you use tracking
> > efficiency
> > > > (+-4%) variation in embedding to get systematic uncertainties?
> > ii)
> > > > Can
> > > > you please do a test where you apply the same variation in the
> > data
> > > > and
> > > > use the respective variation in the embedding and then check if
> > you
> > > > get
> > > > approximately the same sys. variation between the two cases
> > ?(just
> > > > for
> > > > one case which one has a bigger effect).
> > > >
> > > > 2. I like Style-4 (slide18) of figure-1 if you don't want to
> > shift
> > > > the
> > > > published results. In this case, I would suggest using an open
> > black
> > > > star for published results and a filled red marker for your new
> > > > Multifold results. Then you plot your red filled star top on the
> > > > published results (open back mark). In this case, you don't need
> > to
> > > > shift the published results, and no confusion, and will look
> > good.
> > > > 3. SLide19, Fig-1 ratio plot: In this plot, assuming statistical
> > > > uncertainties cancel out. Are these bands only the ratio of
> > > > systematic
> > > > uncertainties? Can you use a separate marker style here in order
> > to
> > > > avoid your mass distribution red star style?
> > > >
> > > > 4. SLide#21: Thank you for including raw distribution here. It
> > looks
> > > > like there is a noticeable difference between raw and Multifold
> > > > levels.
> > > >
> > > > 5. Slide#23: Thank you for including PYTHIA8 curves. I like this
> > > > plot
> > > > and the comparison. Pythia8 and Data are consistent. You could
> > point
> > > > out
> > > > that further study is ongoing to explore mass distribution
> > between q
> > > > vs.
> > > > g using this |Q| cut. This is the main physics of this |Q| cut
> > here.
> > > > Right? (Can you label "PYTHiA8" as "PYTHIA8 Detroit tune" or
> > …STAR
> > > > tune?)
> > > >
> > > > Cheers
> > > > Nihar
> > > >
> > > > On 2022-09-23 20:29, Youqi Song via Star-hp-l wrote:
> > > > > Hi all,
> > > > >
> > > > > I have updated my slides for the preliminary request at:
> https://drupal.star.bnl.gov/STAR/system/files/prelim_request_092222_0.pdf.
> > > > > A few things that I would like to point out:
> > > > >
> > > > > Regarding systematics,
> > > > > - You might have noticed that the systematic errors for
> > multifold
> > > > have
> > > > > gone up by a bit. This is because I realized that before, when
> > > > doing
> > > > > herwig and pythia8 shape variations, I was using pythia6 mass
> > > > > distribution for the misses. Now I changed it so that the misses
> > > > > contribution for prior shape variation is also weighted by the
> > > > mass
> > > > > ratio of herwig (pythia8) over pythia6.
> > > > > - After talking with Isaac, I learned that unfolding systematics
> > > > due
> > > > > to variation of iteration number and variation of prior shape
> > were
> > > > > treated as correlated in previous analyses, while I originally
> > had
> > > > > these added in quadrature. Now I also treat them as correlated
> > by
> > > > just
> > > > > taking the largest contribution to the unfolding systematic as
> > the
> > > > > overall unfolding systematic, and add it in quadrature with
> > > > detector
> > > > > systematics.
> > > > > - Regarding the question whether there's anything still missing
> > > > that's
> > > > > raised during the meeting yesterday, I forgot to mention that we
> > > > > haven't included detector and generator level pT shape smearing.
> > > > This
> > > > > is included in Raghav's and Isaac's analyses because they did 1D
> > > > > reweighting, but we are not sure if it should be included for
> > > > > multidimensional unfolding.
> > > > >
> > > > > Regarding plotting,
> > > > > - For fig. 1, I made the mass distribution plot with the same
> > data
> > > > > points in 4 different styles.- For fig. 1 ratio plot, the error
> > > > band
> > > > > is now centered at 1 and is the quadrature of RooUnfold's and
> > > > > MultiFold's unfolding systematics, divided by the mean values
> > from
> > > > > RooUnfold.
> > > > > - For fig. 2, I also included a plot of the M vs Q correlation
> > > > with
> > > > > raw data before unfolding.
> > > > > - For fig. 3, I have pythia8 curves plotted together with my
> > > > unfolded
> > > > > mass distributions.
> > > > >
> > > > > Please let me know if you have any comments/suggestions.
> > > > >
> > > > > Best,
> > > > > Youqi
> > > > >
> > > > > On Wed, Sep 21, 2022 at 5:47 PM Youqi Song <youqi.song AT yale.edu>
> > > > > wrote:
> > > > >
> > > > > > Hi all,
> > > > > >
> > > > > > I have uploaded my slides here:
> > > > > > https://drupal.star.bnl.gov/STAR/blog/youqi/multifold092222
> > > > > >
> > > > > > Best,
> > > > > > Youqi
> > > > > >
> > > > > > On Wed, Sep 21, 2022 at 5:04 PM Tong Liu via Star-hp-l
> > > > > > <star-hp-l AT lists.bnl.gov> wrote:
> > > > > >
> > > > > > Hi all,
> > > > > >
> > > > > > Please find my pdf in this post:
> https://drupal.star.bnl.gov/STAR/blog/tongliu/Tong-Lius-HP-PWG-updates
> > > > > > Tong Liu
> > > > > > Ph.D. Student '2023
> > > > > > Physics Dept., Yale University
> > > > > >
> > > > > > Tel: 203-435-2130
> > > > > >
> > > > > > On Wed, Sep 21, 2022 at 3:29 AM Nihar Sahoo via Star-hp-l
> > > > > > <star-hp-l AT lists.bnl.gov> wrote:
> > > > > > Hello All,
> > > > > >
> > > > > > We got requests from Youqi and Tong to present their results
> > for
> > > > the
> > > > > > Hot
> > > > > > Quark conference.
> > > > > > And during Youqi's talk at the collaboration meeting, we did
> > not
> > > > get
> > > > > > time to have Q&A.
> > > > > > So let's meet this week to discuss their updates.
> > > > > >
> > > > > > Youqi and Tong, can you please send link of your slides in this
> > > > > > thread
> > > > > > again?
> > > > > > (I didn't get your previous emails, the reason I do not know)
> > > > > >
> > > > > > If anybody wants to discuss their results, please let us know.
> > > > > >
> > > > > > HP-pwg weekly meeting Drupal page:
> https://drupal.star.bnl.gov/STAR/pwg/Hard-Probes/Weekly-HP-PWG-meeting
> > > > > > Zoom Meeting link:
> https://bnl.zoomgov.com/j/1611419615?pwd=VW1hNm43ZDd5d2EvK2R4aEJsQ2ZNZz09
> > [1]
> > > > [1]
> > > > > > [1]
> > > > > >
> > > > > > Meeting ID: 161 141 9615
> > > > > > Passcode: 744968
> > > > > >
> > > > > > Thank you
> > > > > > Barbara, Yi, Sooraj, Nihar
> > > > > >
> > > > > > On 2022-09-19 22:13, Nihar Sahoo via Star-hp-l wrote:
> > > > > > > Hello All,
> > > > > > >
> > > > > > > Last week we discussed a lot at the collaboration meeting, If
> > > > > > there is
> > > > > > > no urgent matter to discuss,  let's cancel this week's HP pwg
> > > > > > meeting.
> > > > > > > Have a great week.
> > > > > > >
> > > > > > > Thank you
> > > > > > > Barbara, Yi, Sooraj, and Nihar
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