sPHENIX discussion of physics

[Anthony Frawley <afrawley AT fsu.edu>]

Dear Yuanjing,

I like your slides. I have a few comments:

Please replace the Upsilon mass spectrum on slide 3 with the pp version on slide 10. The one on slide 3 is old - for our final tracking configuration, the Y(1S) mass resolution is about 87 MeV.

The plots on slide 8 are also old, but they should be similar enough to current performance for this purpose. I do suggest covering up the "TPC+INTT" text in the legend for the momentum resolution plot. The resolution is the same with and without the MVTX, and we are planning to have the MVTX.

Note that in the just completed sPHENIX review we used 50 kHz collision rate as our maximum. This is based on the expectation that CAD can reduce the diamond size so that most of the luminosity falls within our acceptance - which reduces our background without much loss in our usable luminosity. I will send you (privately) a replacement for the DCA plot on slide 13 that matches that assumption.

FYI, for central Au+Au at 50 kHz collision rate, our current simulations give us 115 MeV mass resolution. But that is with very simple clustering. We expect that state-of-the-art clustering will bring that below 100 MeV - hence that is what is shown in the right hand plot on slide 10.

Slide 11:

First bullet: "precious" -> "precise"

Second bullet: I think the Y(3S) will not be doable in central collisions. The reason is that the Drell Yan background under the 3S is now projected to be larger than it was in our initial estimates. Combined with the very stron suppression of the 3S, this makes the signal/background small, and we do not expect a measurement to be possible with the currently planned luminosity.

Cheers

Tony

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From: sPHENIX-physics-l <sphenix-physics-l-bounces AT lists.bnl.gov> on behalf of Yuanjing Ji <jiyj AT rcf.rhic.bnl.gov>
Sent: Saturday, June 1, 2019 1:02 PM
To: sphenix-physics-l AT lists.bnl.gov; sphenix-hf-jets-l AT lists.bnl.gov
Subject: Re: [Sphenix-physics-l] RHIC/AGS user meeting presentation

 

Hi all,

Please find my updated slides in:

https://www.star.bnl.gov/~jiyj/sphenix/AUM_v2.pdf

Comments and suggestions are welcome!

Thanks and regards,

Yuanjing

On May 30, 2019, at 16:40, Yuanjing Ji <jiyj AT rcf.rhic.bnl.gov> wrote:

Hi all,

Please find my slide on "future heavy flavor program at sPHENIX" for RHIC/AGS user meeting in the following link:

https://www.star.bnl.gov/~jiyj/sphenix/AUM.pdf

Any comments and suggestions are highly appreciated.

Thanks,

Yuanjing

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