sPHENIX is a new detector at RHIC.

[Anthony Frawley <afrawley AT fsu.edu>]

Hello Gunther,

I attach some plots for the Y(1S) mass resolution. All are without the MVTX, and with 50 ns SAMPA chip peaking time.

The first is for low occupancy events (mass resolution 86 MeV). This is the ultimate resolution limit

The second is for the Y(1S) embedded in central Hijing (0-4 fm). This shows what we expect at present for the mass resolution for central events integrated over a store. 

The mass resolution for single central Hijing with no pileup is 106 MeV. That is not a realistic scenario.

Question for Ed: If we cannot meet the 100 MeV UPP with the existing clustering, is that a problem for this review?

Thanks

Tony

---

From: Gunther M Roland <rolandg AT mit.edu>
Sent: Friday, April 27, 2018 9:39 AM
To: jhuang AT bnl.gov; Perepelitsa, Dennis; Rosi Reed; lajoie AT iastate.edu; O'Brien, Edward; Haggerty, John; Glenn Young; Anthony Frawley; Morrison, David
Cc: sphenix-l AT lists.bnl.gov
Subject: UPP questions

 

Friends,,

Maria just reminded us that we will have a dry-run of the CD-1 review plenary talks next Wednesday. I am not sure we will quite have the final plots at that time, but we need to figure out what the line of argument is going to be.

We have a nice set of new simulations for the MIE configuration for e.g. jet energy resolution and various physics plots. I'm now thinking of how to make the connection to the UPPs for the OPA talk, and I'm finding that not so easy.

As an example, the Jet resolution UPP in my notes is "Jet resolution of < 150%/sqrt(E)" (did we specify at which E, as the resolution does not go as sqrt(E), but has a constant term from the AuAu underlying event?). Our simulations however show a resolution that is much better than that. E.g. 15% at 50GeV from simulations vs 150%/sqrt(50) = 21% from the UPP.

So, my questions/suggestions:
- I assume it is ok if the UPP is somewhat relaxed compared to the performance in simulations?
- We probably should add a line on the performance plots reflecting the UPP performance
- We should add a set of points corresponding to the UPP performance to the physics plots
- for the physics plots, one needs some to provide some scale of why we want to reach a certain performance. I'm planning to argue that we want comparable performance to that at LHC (e.g. gamma-jet balance uncertainties, Upsilon resolution). Any better ideas?
- for the t-shirt plot, it would be nice to have for comparison also the current RHIC status (applies only to jets/hadron RAA) and a backup plot of how much the MIE vs reference acceptance costs us

Question to Dennis/Rosi: Any chance of getting a photon resolution plot from simulation to compare to the photon UPP of <15%/sqrt(E) photon resolution? I think it would be good to fold this into the physics plot.

Question to Tony: Where can I find the latest Upsilon mass plot for pp? The UPP (Y(1s) mass resolution < 100MeV) probably needs to refer not just to the system, but also specific running conditions: single central Au+Auevent, max pileup, average pileup? It would be good to have a comparison of the resolution for pp, single central Au+Au and central Au+Au at max pileup (beginning of store) to see where we stand.

Cheers,

Gunther

Attachment: Upsilon_mass_res_100pions_check.pdf
Description: Upsilon_mass_res_100pions_check.pdf

Attachment: Upsilon_mass_res_central_0_to_200khz.pdf
Description: Upsilon_mass_res_central_0_to_200khz.pdf