sPHENIX EMCal discussion

[Alexander Bazilevsky <shura AT bnl.gov>]

Hi Craig,

After your comment I was curious to see how much the position resolution 
would degrade in the central HI collisions. We saw Joe's plots 
illustrating the effect on the energy resolution. I've quickly looked in 
the simulation trees and produced the attached plot, which is position 
resolution in the barrel EMCal in tower units (here it is in phi 
direction) for single photons (blue) vs when they are embedded in the 
central HI (red). The usual fits gave me

0.057 + 0.10/sqrt(E) for single photon case and

0.059 + 0.21/sqrt(E) for embedded case

The sum is quadratic. And, again, it is in tower units. In terms of mm 
units, the constant term is ~1.3mm, which looks the same for both cases. 
The resolution for single photon is quite similar to PHENIX PbSc if 
presented in tower units, so nothing surprising here. And the effect of 
the UE looks not critical, particularly for dir. photon measurements (at 
higher pT).

Regards,

Sasha.


On 5/4/18 8:03 AM, Craig Woody wrote:
>  It may degrade the position resolution slightly, but our position 
> resolution for photons will already be degraded significantly by the 
> underlying event in central collisions.

--
Alexander Bazilevsky
Brookhaven National Laboratory, Bldg. 510D, 2-232
Upton, NY 11973 Tel: 631-344-3712
Email: shura AT bnl.gov
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