Changhyun Oh - ZDC simulation, Lambda reconstruction
- Lambda reco using EMCAL + HCAL, and just HCAL.
- Why doesn’t the performance get a little worse with the inclusion of the EMCAL?
- It was found during the discussion (by looking into DD4HEP) that LYSO is the default in dd4hep, which is not correct for the baseline configuration in the simulation campaigns.
- PbWO4 is supposed to be the default until the LYSO is demonstrated to be able to provide the right performance.
- Results of this study do not seem consistent with: https://arxiv.org/pdf/2412.12346
- Please review the study and confirm with Miguel et al.
Email from Silvia Sept. 26th in-regards to the ZDC LYSO vs. PbWO4
Recommendations:
The adoption of the 162 cm-long SiPM-on-tile calorimeter is confirmed.
It is requested to continue to assess the performance in more realistic simulations, including SiPM dark noise and physical backgrounds and in particular beam gas interaction.
It is clear that while long crystals in front of the SiPM-on-tile section will degrade the ability to reconstruct the vector direction for EM showers, a short crystal solution has not been simulated or optimized. A possible path is to configure the EM section of the ZDC for the physics focus of an EIC running period by including it for eA running where the detection of low-energy photons is important to tag incoherent interactions, and removing it for ep running. This places a premium on reserving space for low-energy photon crystal section, but an argument cannot be made at this time to replace the existing baseline using long PbW04 crystals.
To advance the case of short LYSO crystals, the proponents need to address the following items:
- Implement in the simulation a reasonably realistic LYSO response;
- Optimize the crystal length for the detection of low-energy photons;
- Select the most adequate sensors for the LYSO crystals (SiPM versus APV).
Chia-Ming Kuo - Beam tests for LYSO and PbWO4
- Two beam tests for LYSO and PbWO4 carried out.
- First beam test - 47 MeV positrons
- First set of results showed of a lot non-linear behavior in the energy response.
- Data matched MC quite well.
- Raw E resolution (without corrections or calibration) was 19.5%, and improved to 15.6% after removing beam energy uncertainty. This is very promising for the low-E photon tagging.
- Second beam test (47 to 800 MeV positrons)
- larger beam energy range, two new protypes (LYSO+APD readout and PbWO4+SiPM readout) --> initial energy response now looks linear.
- Need to finalize geometry (transverse size), and also what the optimal LYSO crystal length should be for best performance.
- Can likely shrink the transverse size of EMCAL to save space near the beam pipe --> Need to know if this is really possible, and by how much we can shrink. Someone needed to run simulations.
Sean Preins - ZDC prototype at STAR.
- Showed both results from the beam test (running parasitcally with STAR on the East platform), and the manufacturing procedure for the prototype.
- Very advanced work on the manufacturing process.
- Would like to see the IV curves after the first year of running to get an idea of how much radiation damage has occurred under semi-realistic conditions.
JiaJun Huang - simulation of ZDC prototype being tested at JLAB (and at NSRL at BNL)
- Simulations are for JLAB 4 GeV positron beam, NSRL 2 GeV proton beam, and NSRL 1 GeV/n Fe-56 beam.
- The MIP energy deposits seem a little strange. Should investigate GEANT settings for hadrons. May also be good to try a neutral hadron, and not allow it to decay to separate ionization interaction from purely hadronic ones.
Other points
Ralf asking about lambda generation - put him in touch with Stephen Kay et al.
Yulia also commented that she, Tanja, Richard, and Dmitry are working on simulations of this with their generator, as well.
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