Many physics processes at the ILC are characterised by multi-jet final states sometimes accompanied by charged leptons and/or missing transverse energy associated with neutrinos or, perhaps, more exotic particles. The reconstruction of the invariant mass of two or more jets will provide a powerful tool for identifying the physical process and in rejecting background. In addition, decays commonly involve a cascade through several massive states, which can be elucidated by mass reconstruction.
An international collaboration CALICE develops and optimises central calorimetry for the ILC. UCL is one of the UK groups in this collaboration and was leading R&D on data acquistion and was also involved in simulation studies and testbeam running.publication. UCL still continues to contribute to CALICE papers and through our common DAQ work within the AIDA-2020 framework.