Strong interaction effects in exclusive B decays

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With the Large Hadron Collider (LHC) first run successfully completed in 2013 and a wealth of data being continuously analysed and published, the physics of the B mesons, i.e. mesons containing a b quark, has entered a new exciting era. One of the four main experiments at the LHC, namely the LHCb experiment, is dedicated to the study of the B mesons. Their numerous decay channels offer the opportunity to make precision tests of the Standard Model (SM) and perhaps more interestingly, to discover new physics beyond the SM. Data taking will resume in 2015 at peak energy and higher luminosity. In the next 5 years, various observables will be measured with increasing precision by the LHCb collaboration and theory input will clearly be required to interpret the data as well as to guide future experiments in this field. In this research, we focus on rare exclusive B decays to light mesons, i.e. B decays to specific final products. Such decays are especially appealing because they are relatively easy to access experimentally especially in an environment like the LHC. On the other hand, the theory of such decays is challenging because they involve strong interactions effects which are not computable using perturbation theory in Quantum Chromodynamics (QCD), the fundamental modern theory of strong interactions. In our research, we model these effects by using a relatively new technique which involves exploiting a correspondence between QCD in physical spacetime and a string theory in a higher dimensional curved space called anti de Sitter (AdS) space. This correspondence is called AdS/QCD. At the same time, we will investigate signals of new physics in those rare B decays. These rare decays are sometimes quite susceptible to the interference from much heavier particles that may be out there but have not been discovered yet. Our proposed investigation is to have a better understanding of these interferences which can then be compared with the experimental data from the LHC. This comparison will hopefully give us some clues on how the SM can be extended towards a more complete theory. With our research, we hope to contribute to the efforts of the particle physics community to discover new physics at the LHC. At the same time, we are testing AdS/QCD which offers insights into the unsolved problem of confinement of quarks in hadrons.