Fakulta¨t fu¨t PhysikUniversita¨t Karlsruhe (TH)Karlsruhe Institute of Technology, KITInstitut fu¨r Theoretische TeilchenphysikRare hadronic B decays in the MSSMand in other models of new physicsLars Hofergeboren am 21.08.1981 in AschaffenburgVollsta¨ndiger Abdruck der von der Fakulta¨t fu¨r Physik der Universita¨t Karlsruhe zur Erlangungdes akademischen Grades einesDoktors der Naturwissenschaften (Dr. rer. nat.)genehmigten Dissertation.Pru¨fer der Dissertation: 1. Prof. Dr. Ulrich Nierste2. Prof. Dr. Dieter ZeppenfeldTag der mu¨ndlichen Pru¨fung: 05.11.2010iABSTRACTIn this thesis we study several aspects of new physics in rare hadronic B decays. First weconsider the Minimal Supersymmetric Standard Model (MSSM) with Minimal Flavour Viola-tion (MFV). Here, interesting effects arise for large values of tanβ due to the enhancementof down-quark self-energies. These effects are well-studied within the decoupling limit, i.e. inthe limit of supersymmetric masses far above the electroweak scale. In this thesis we addressthis topic in a framework that goes beyond this limit: We derive several resummation formu-lae for arbitrary values of the supersymmetric mass parameters and clarify their dependence onthe renormalisation scheme. Furthermore, we studytanβ-enhanced corrections to couplings in-volving genuine supersymmetric particles. This cannot be done consistently in the decouplinglimit with these particles being integrated out.