sPHENIX Event Plane Detector discussion

[pinkenburg <pinkenburg AT bnl.gov>]

P.S. one other difference is that (likely) you use the tiles and not the 
G4Hits anymore. Do you have systematic offsets between the G4Hits 
location and the tile location? Does the mean G4Hit phi/radius in each 
tile (integrated over many events) match what the tile geometry says?

On 4/27/2023 11:27 AM, pinkenburg wrote:
> Hi Ejiro,
>
> I sincerely doubt that this is pileup. The epd integrates over a 
> single bunch crossing and for a single bunch crossing the pileup is 
> somewhere in the sub percent range. Basically the events you get from 
> the sims for the epd are single events without pileup. Also you can 
> remove pileup events from your analysis if you want to make sure
>
> Chris
>
>
>
> On 4/27/2023 11:14 AM, Ejiro Umaka wrote:
> > Hi all,
> >
> > I've been working on the event plane determination for the EPD (and 
> > other subsystems). Initially (~ 2 years ago) when we first looked at 
> > the EPD raw psi_2, we got a flat distribution, but the most recent 
> > simulation results were not. The only thing I can think of as to what 
> > changed between then and now is pile-up in the current simulations.
> > I proceeded to look at the phi -weighted psi_2 distributions and they 
> > are flat (attached)!
> >
> > I'd like to discuss this further at the EPD/bulk meeting next week.
> >
> > Best regards,
> > Ejiro

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Christopher H. Pinkenburg       ;    pinkenburg AT bnl.gov
                                ;    http://www.phenix.bnl.gov/~pinkenbu

Brookhaven National Laboratory  ;    phone: (631) 344-5692
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