Beam-test results of a capillary based dual-readout fibre-sampling calorimeter prototype

The journey of calorimetry in particle physics from a crude apparatus for stopping particles to an instrumentation for precision measurements has taken place over several decades. Understanding the physics of energy deposition of particles via interactions with matter and developing techniques for conversion of deposited energies into human readable signals have been crucial features for learning. Monte Carlo based simulations provided inputs in understanding the nature of electromagnetic showers. Hadronic showers are even more complex and are fully explored with simulation models. The non-relativistic component of the shower that is dominated by processes at the nuclear level, is still poorly described by the hadronic shower development package provided by Geant4. Therefore, the construction and characterisation of calorimeter prototypes becomes an excellent way to learn more about hadron showers. The INFN-Pavia group has been developing prototypes of novel modular structures of Dual-Readout calorimeters in order to finalise the design and concept of calorimeters aimed to perform precision measurements in experiments proposed at future circular lepton colliders. I spent one half of the first year familiarising myself with the activities of our group and then performed simulation studies on an electromagnetic-scale Dual-Readout calorimeter. The construction of the electromagnetic-scale novel module started at the beginning of the second year of my doctoral studies. It took eight months for the detector to be ready for tests with beams at two facilities, DESY and the Super Proton Synchrotron at CERN. During the final year of my PhD, I analysed data samples taken with the CERN test beams. Chapters 1 and 2 are dedicated to describe concepts of calorimetry in particle physics and the state-of-the-art of the Dual-Readout calorimetry, respectively. Chapter 3 out- lines possible scenarios of the post-LHC era, i.e., the future projects for high-energy collider physics. This chapter also elaborates on the physics potential at the FCC-ee collider, the IDEA detector concept that has been proposed by the researchers of various INFN groups and the role of Dual-Readout calorimetry in precision measurements. Chapter 4 provides the designs and dimensions of the two fibre-sampling calorimeter modules, an electromagnetic-scale and a hadronic-scale, with detailed description of the construction steps of the electromagnetic-scale module and some additional work required for the construction of the hadronic-scale module. On the other hand, Chapters 5 and 6 are dedicated to describe the simulation studies of the electromagnetic-scale module along with the Geant geometry of the hadronic-scale module and the analysis work related to the CERN beam test of the electromagnetic-scale module, respectively. Members of the Pavia RD FCC group are also part of the ATLAS experiment at the LHC and hence, I had the chance to join the ATLAS collaboration too during my PhD. As a result, in addition to the above mentioned work, I had the opportunity to participate in the ongoing construction activities for the Micromegas chambers for the ATLAS New Small Wheel and software tool development for the online Data Quality Monitoring for the Micromegas. When the construction activities on the Micromegas were completed, I started working on the software tool development and continued for one year. This participation allowed me to qualify as an ATLAS author in January 2021 and become a Muon Desk Shifter in the ATLAS Control Room during the test runs of 2021 and the LHC Run 3 of 2022. Appendix A begins with a short introduction of the ATLAS experiment and is dedicated to describe the mentioned ATLAS activities. Conclusions on the lessons from the electromagnetic-scale prototype tests have been drawn in Chapter 7. Some objectives on the readout of the upcoming significant containment prototype are also shortly discussed in this chapter. The Bibliography [1] to [79] concern calorimetry and future collider projects, whereas the rest corresponds to the ATLAS experiment and aspects related to it.