Harnessing the Power of B -> D(Multi-body)K Decays at LHCb for a Precise Measurement of the CKM Angle Gamma

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The universe is believed to have begun according to a cosmological model that scientists refer to as the 'Big Bang'. It describes how both time and space were created giving birth to a primordial 'fireball' that has since expanded and evolved into today's current universe. A variety of evidence has been obtained that strongly supports the Big Bang model of the universe; however, there is one peculiarity that remains unexplained. According to the model, in addition to the 'stuff' we refer to as every day ordinary matter, the Big Bang should have produced equal amounts of something called antimatter. Antimatter, as the name implies, can be described as the opposite of ordinary matter. Whilst a matter particle will have a definite mass and electric charge, its antimatter partner will possess the same characteristics except for an opposite electric charge. Despite what the Big Bang model predicts, scientists find that almost all of today's observable universe is made up of matter. The question is, therefore, where has all the antimatter gone? This remains one of the greatest unsolved mysteries in modern day physics. If matter and antimatter were created in equal quantities, then there must exist some process within the laws of physics that results in the asymmetry we see today. One such process is that referred to as 'CP-violation'. If nature treats matter and antimatter in equal ways then the symmetry, CP, would be preserved. Quite clearly, however, nature does not preserve this symmetry and so the physical laws must be different for matter and antimatter. That is, CP is violated. Within the field of particle physics, physicists have developed a mathematical theory which describes three of the four fundamental forces seen to interact with the elementary particles of matter (gravity being the unaccounted force). To this present day, almost all experimental tests of the three forces described by this 'Standard Model' (SM) of particle physics have produced results that agree with its predictions. It is, therefore, regarded as a triumph of modern day science. At its foundation, the SM is based on the theory of Quantum Mechanics (QM) which considers each fundamental particle as a wave. When represented mathematically, the resulting 'wavefunction' describes how the particle will evolve in time whilst obeying the laws of QM. The SM actually permits the existence of CP-violation within certain types of particle decays, and this type of symmetry breaking has been experimentally verified. The problem that remains, however, is that this source of CP-violation is insufficient to explain the huge matter-antimatter asymmetry. Due to this and other reasons (such as the fact that gravity is unable to be incorporated), it is believed there must be physics beyond that described by the SM; so called New Physics (NP). Although CP-violation has been observed, almost all CP-violation parameters in the SM have yet to be precisely measured. In fact, making a world's best measurement of one of these parameters, called gamma, forms the main objective of my research proposal. Without a precision measurement of gamma it will not be possible to identify sources of CP violation within potential NP. It is, therefore, critical that gamma is thoroughly constrained. Gamma is best accessed by analysing the decay properties of particles called D mesons that have been produced in the particle decay chain B->DK. Since these are quantum particles, their behaviour is governed by QM and, just like any other wave, the D meson wavefunction possesses amplitude and phase information. Detailed knowledge of both these properties is necessary in order to access the parameter gamma. However, it is only possible to extract both amplitude and phase information by analysing in conjunction the datasets of two different experiments: LHCb and CLEO-c. Only then will it be possible to precisely determine the SM parameter gamma and provide a step towards discoveries of NP.