STAR HardProbes PWG

["Evdokimov, Olga" <evdolga AT uic.edu>]

    Dear Rongrong,

 

For biggest jets we, naturally, have the smallest acceptance. The plot on slide 4 shows correlations for R=0.3 jets; these are reconstructed up to (1-R)=0.7 in eta, which  together with the charged hadron selection of +/- 0.5 give the deta acceptance of +/-1.2

 

For your second question – one could not use |deta|<0.5 for UE; this is where the jet peak sits. Please take a look at slide 5 where jet and EU regions are sketched to illustrate this. If you propose to use +/- 0.5 in deta but “go away” from jet in dphi – we have considered this possibility in this and other such analyses, and this route is prohibited by the vn presence and the unknown jet-to-RP coupling (as well as presence of away side quenched jet which is not modeled well in any event generators to date).

 

Best regards,

Olga

 

 

From: Star-hp-l <star-hp-l-bounces AT lists.bnl.gov> On Behalf Of Ma, Rongrong via Star-hp-l
Sent: Wednesday, March 22, 2023 3:45 PM
To: Dale-Gau, Gabe <gdaleg2 AT uic.edu>
Cc: STAR HardProbes PWG <star-hp-l AT lists.bnl.gov>
Subject: Re: [Star-hp-l] [Star-talks-l] Updated Slides for Hard Probes 2023 (Gabe)

 

Hello Gabe, Olga

 

Thanks for your responses. 

 

For R = 0.5 jets, I understand that the eta cut o jets is |eta_jet| < 0.5. Do you also use |eta_track| < 0.5 cut which limits the dEta range from -1 to 1? It does not seem to be the case as one can see entries beyond |dEta| = 1 on slide 4. If your cut on tracks is |eta_track| < 1.0, it shouldn't be so difficult to get to |dEta| = 1, right?

 

On the second backup slide, you show the dEta distribution for UE (red points). Do you use UE within 0.5 < |dEta| < 1.0 for the projection of dPhi? If so, why not use the |dEta| < 0.5 range? Actually, how do you get the entries within |dEta| < 0.5 in the first place given that the UE semi-circles are far away from the jet axis in eta?

 

Sorry for these naive questions. I should have followed the analysis more closely. 

 

Best

Rongrong

On Mar 22, 2023, at 3:38 PM, Gabe Dale-Gau <gdaleg2 AT uic.edu> wrote:

 

Rongrong,

 

To add to Olga's response, the reason we see this effect specifically in the center bins of dphi in R05 and not in the other dphi bins is due to the semicircular geometry employed in our UE definition. This is highlighted on slide 22 in backup. For all other R the semicircle does not reach the edge of our distribution in deta, but for R05 specifically, the area reaches the edge around dphi = 0.

 

Best,

 

Gabe

 

On Wed, Mar 22, 2023 at 10:04 AM Ma, Rongrong <marr AT bnl.gov> wrote:

Hello Gabe

 

Thanks for including those backup slides. 

 

If I understand correctly, what you mean is that the UE distribution close to the edge (|deta| ~ 1) has large error bars, which contributes to the large errors seen in dphi ~ 0. Is this correct? If so, why don't they contribute to other dphi bins? Also, since your jet-hadron range is 0.5, I would naively expect you only use UE within |deta| < 0.5. Do I miss anything?

 

Best

Rongrong

On Mar 21, 2023, at 4:21 PM, Gabe Dale-Gau via Star-talks-l <star-talks-l AT lists.bnl.gov> wrote:

 

Conveners,

 

Thank you for all of your comments and input. 

I have updated my Star-Talks submission here:

https://drupal.star.bnl.gov/STAR/presentations/Hard-Probes-2023/Baryon-Meson-Ratios-AuAu-and-pp-collisions-sqrtsNN-200-GeV

 

I have implemented many changes in this version to address all of the comments I received from Nihar and Barbara, as well as general rephrasing throughout to simplify text on slides.

 

Rongrong, the first three slides in the backup section are included to address your question about the origin of two strange points in the Au+Au correlated jet peak signal.

 

I will create a separate drupal page with figures included as individual files shortly.

 

Let me know if you have further questions or comments.

 

Many thanks,

 

Gabe

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