Minutes for the IDEA Calorimetry Meeting (31/01/2020) - SW session

Iacopo and Lorenzo set the path for a regular meeting, approximately bi-weekly, where the SW activities related to the IDEA Dual-Readout calorimeter will be presented. At the same time, the hardware related activities will be presented to help sharing ideas from people involved in these works. 

A first presentation by Lorenzo summarized the activities that have been carried on in Italy during 2019. The main result was having created a full-simulation, GEANT4 based, in order to study the performances of a fully projected tower-based DR calorimeter. The detector geometry has been optimized for the IDEA Detector and the light yield was tuned to latest SiPM-driven test beam data. Several results were showed about calorimeter response, calorimeter calibration, electromagnetic performances, hadronic performances, jet performances and single particle identification. The attention was driven to the several areas were collaboration is possible and needed (see slides for details). Also activities on fast-simulation, pre-shower simulation, reconstruction algorithms and machine learning techniques, were briefly presented. 
The main goal was identified in carrying on the calorimeter performance studies and detector optimization by targeting a single code shared among the IDEA Collaboration. The Sussex group will perform an independent test on the portability of this code and a TWiki page, linked to an updated repository, will be created soon. The need to keep the computation load as small as possible was also pointed out as a strategic feature in code developing. 
The need to start looking at FCCSW for future simulation activities was mentioned as an high-priority task. Finally, the need to work on a  GEANT4 simulation of the future tube-based calorimeter was pointed out. This represents a good possibility for newcomers that want to start working in a simplified environment. 

A following presentation was given by Sang Hyun Ko for the Korean community. The topic was the 2019 activity on the GEANT4-based simulation of a Dual-Readout fully-projective calorimeter. Several results about signal simulation, calibration, electromagnetic performances and hadronic performances were presented (see slides for details). While the electromagnetic energy resolution was similar to the one presented in the previous talk, some differences between the two presentations emerged. The geometry designed by the Korean colleagues was inspired by the 4th-Concept Detector Experience, hence adopting a round geometry for the endcap structure, while the IDEA Detector is designed to house a perfectly cylindrical drift-chamber. Moreover, the calibration techniques, even though both performed with electrons, did not follow the same path. The Italian community decided to correct equalization constants in order to mitigate the different response to electrons at the less-stimulated towers. On the other hand, this correction is not applied by the Korean colleagues. More interesting were differences found among the hadronic performances. The Italian community showed some charged pion energy distributions reconstructed with the dual-readout method. While the mean energy depends on the Physics List used, the energy resolution was always compatible with 0.3%/sqrt(E). The Korean community showed single pions energy distributions reconstructed with the dual-readout method with an energy resolution of the order of 20-22%/sqrt(E). This difference is true even if the same Chi factor is used for the dual-readout correction. 

Given what has been said during the meeting, we suggest to both communities to present in the following meetings results needed to understand the most critical points: 

1. Calorimeter response to electrons vs. tower number and calibration constants vs. tower number
2. Cherenkov and scintillation signals for 40, 60 and 80 GeV charged pions vs. tower number. Reconstructed energy with Chi=0.29 for the same data. The FTFP-BERT Physics List should be used if not differently said.
3. Chi factor estimation with simulated data. 

Moreover we underline the need to have a better coordination on the software activities and to not duplicate efforts on the same studies. 

Next meeting is scheduled for 14/02/2020. An email notification will be sent in advance. 

Kind Regards, Iacopo and Lorenzo