The kaon electromagnetic mass difference in AdS/QCD

Sammanfattning: In this thesis, a holographic model for quantum chromodynamics (QCD) is used to estimate the electromagnetic contribution to the kaon mass difference. The principal ideas of the model are inspired by the AdS/CFT correspondence, which is believed to be exact. The calculation is first performed theoretically, highlighting the expansion of the result into a diagrammatic structure referred to as Witten diagrams, and similar to that of Feynman diagrams of perturbative quantum field theory. To this end, several relations between the propagators are derived. An outline of the full theoretical calculation is given before proceeding to attempt to evaluate numerically the electromagnetic mass difference to first loop order. This calculation is done in Euclidean space, and the results are fitted to analytical formulae to extrapolate to Minkowski space. The final values are off by several orders of magnitude, which is believed to be in part due to an unidentified numerical glitch, but the overall expected physical behaviour, near the mass pole, is reproduced correctly by the model.