Study ePIC performance in coherent J/psi diffractive pattern.
- Updated track and J/psi selections.
- Use Ecal energy instead of track for backward electron
--> Better t resolution
- Additional J/psi pseudorapidity requirement to reduce scattered electron contamination
--> Better t resolution in both dielectron and dimuon channels.
- The dimuon channel gives better t resolution, but the t resolution with ePIC is still objectively bad.
- Caveat: true PID is used.
- Backward tracking/calorimeter will be the key to coherent J/psi diffractive pattern measurements.
