Particle Flow Calorimetry

The next accelerator for particle physics experiments after the Large Hadron Collider (LHC) is likely to be a lepton collider, for example the ILC and CLIC. The next generation lepton collider will have the capability to precisely measure the properties of the Higgs boson and other particles expected to be discovered at the LHC. For example, it is not only important to discover the Higgs boson but also to measure precisely its properties like mass and decays modes. These precise measurments will help to establish if the particle found at the LHC is really the Higgs boson of the Standard Model or if it is something else. The detectors at a future lepton collider are being designed to have the required accuracy to perform these measurements. For any physics beyond the Standard Model, for example supersymmetric particles or extra dimensions, there is also a need to have precise measurements of the event properties in order to understand the underlying theory. Most of the decay modes of these particles contain many particles in their final state, clustered together in so-called 'Jets'. The capability to measure the momentum and the energy of these jets is vital to make precise measurements of particle properties. Particle flow calorimetry is a new approach combining the individual strength of both the momentum measurements in the tracking chambers and energy measurements in the calorimeters. Particle flow calorimetry can potentially improve the jet energy resolution by a factor of two compared to more traditional approaches. Particle flow calorimetry requires highly segmented detectors and sophisticated software reconstruction algorthms to utilitise this information. Essentially one attempts relate the energy deposits in all parts of the detector with the particles produced in the collision. This is challenging and requires the development of new techniques to evaluate the potential of particle flow calorimetry. Within the context of the ILC the UK is the worldwide leader in research into this new technique. This proposal aims to develop particle flow calorimetry in a more general sense and to perform and publish the definitive study on this topic. The work would have direct application to the design of next generation collider experiments.