sPHENIX is a new detector at RHIC.

["Perepelitsa, Dennis" <dvp AT bnl.gov>]

Hi Megan,

2. You discuss photon-tagged fragmentation functions on slides 26-28, but I found the connection between the text and plots somewhat hard to follow. Some suggestions:

A. On slide 27, you talk about how RHIC is ideal for measuring direct photons — could it make sense to show a plot on photon reconstruction in Au+Au? 

The point is the cross over from pi0 dominated to direct photon dominated at high pt which does not happen for LHC. I'm not sure how well the photon reconstruction plot makes this argument

I think it is fine to make this more general point (which is a gift from the collision energy rather than anything having to do with sPHENIX per se) — my suggestion was that it could be used as an opportunity to show off more of our developing capabilities on the software/simulations side if you wanted to do so.

 

B. I think the plots on the bottom of slide 27 are supposed to back up your second bullet point, but that’s not visually evident (the LHC plot has as much of a “shift” as the RHIC one) — could I suggest to show the bottom two panels in the JEWEL projections in Fig 1.33 of the MIE proposal instead? 

I can't find the plot you are referring to. I don't see a figure 1.33 in the MIE. Are you referring to a different document? In any case I'll tone down the statement.

 

I believe it is just Fig. 1.33 on page 34 here: https://arxiv.org/pdf/1501.06197.pdf . I attach a copy of it. 

Dennis 

On Jun 20, 2017, at 6:29 AM, Megan Connors <meganEconnors AT gmail.com> wrote:

Hi Dennis,

Thanks for the detailed comments. I have questions embedded in your comments below. 

Thanks,

-Megan

On Tue, Jun 20, 2017 at 12:52 AM, Perepelitsa, Dennis <dvp AT bnl.gov> wrote:

Hi Megan,

This looks like a nice set of slides. 

Even though we have newer performance plots from the Collaboration Meeting which explore our ability to measure jets in Au+Au collisions with the most realistic G4 simulations to date, I agree with your strategy of sticking to previously shown MIE proposal and QM17 plots until our public note circulation & approval process is complete.

Besides this, I have just two comments: 

1. I think one has to be a little careful with slides 5-7. The numbers in the orange box are not uniformly used for all of the projections you show. Just for example, I believe for the prompt photon RAA projections we made in late 2014, we assumed that (1) one could successfully trigger on high-pT photons in Au+Au and (2) one could take events from all z-vertex positions, so in total this represents much more than the 20 billion Au+Au 0-20% events recorded with the MB trigger inside |z| < 10 cm. In any case, I would stress that the plots on slides 5-7 are based on the particular set of projections we made while preparing the MIE proposal document and as you note in slide 9 we are incorporating more specific, updated guidance from C-AD and are in the process of fleshing out a full run plan.

I will double check the RAA plots but I was actually using slides 5-7 to point out the assumptions made in different plots and that we are working toward a new set of performance plots with the latest framework that will use the 5 year run plan as a basis for the projections.

 

2. You discuss photon-tagged fragmentation functions on slides 26-28, but I found the connection between the text and plots somewhat hard to follow. Some suggestions:

A. On slide 27, you talk about how RHIC is ideal for measuring direct photons — could it make sense to show a plot on photon reconstruction in Au+Au? 

The point is the cross over from pi0 dominated to direct photon dominated at high pt which does not happen for LHC. I'm not sure how well the photon reconstruction plot makes this argument

 

B. I think the plots on the bottom of slide 27 are supposed to back up your second bullet point, but that’s not visually evident (the LHC plot has as much of a “shift” as the RHIC one) — could I suggest to show the bottom two panels in the JEWEL projections in Fig 1.33 of the MIE proposal instead? 

I can't find the plot you are referring to. I don't see a figure 1.33 in the MIE. Are you referring to a different document? In any case I'll tone down the statement.

 

C. From slide 28, one gets the impression you are suggesting we measure reaction-plane-dependent-photon-tagged-jet-fragmentation-functions, which would be an incredibly selective measurement… perhaps slide 28 is intended to talk about photon-tagged measurements more generally?

Yes, I am talking more generally and the photon-tagged FF is on the to do list. I removed FF from the title of the slide. 

 

Good luck with the talk, 

Thanks again!

 

Dennis

On Jun 19, 2017, at 6:51 PM, Megan Connors <meganEconnors AT gmail.com> wrote:

Dear all,

My slides for tomorrow's jet workshop at the users meeting can be found here:

https://www.dropbox.com/s/obaog2to4djgytc/sphenix_AUM2017_jets_connors.pdf?dl=0

Sorry for the late posting. It needs to be finalized by Tuesday by noon. 

Thanks,

-Megan

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Dennis V. Perepelitsa

Assistant Professor, Physics Department

University of Colorado Boulder

Dennis V. Perepelitsa

Assistant Professor, Physics Department

University of Colorado Boulder

Attachment: jewel_summary.pdf
Description: jewel_summary.pdf