F = 2 processes in the MSSM in large tan β limit

We discuss corrections to ∆M B d , ∆M Bs and to the CP violation parameter ε in two examples of (generalized) minimal flavour violation models: 2HDM and MSSM in the large tan β limit. We show that for H + not too heavy, ∆M Bs in the MSSM with heavy sparticles can be substantially smaller than in the SM due the charged Higgs box contributions and in particular due to the growing like tan 4 β contribution of the double penguin diagrams involving neutral Higgs boson exchanges. The determination of the CKM parameters is the hot topic in particle physics. In view of forthcoming precise results from B-factories, it is particularly important to discuss possible effects of new physics contributions to ∆F = 2 processes: ∆M B d and ∆M Bs mass differences and to the ¯ K 0-K 0 CP violation parameter ε. In general models of new physics fall into the two following broad classes: • Models in which the CKM matrix remains the unique source of flavour and CP violation-so-called minimal flavour violation (MFV) models [1, 2] and their generalizations (GMFV models). In the GMFV models the non SM-like operators contribute significantly to the effective low energy Hamiltonian [3]. • Models with entirely new sources of flavour and/or CP violation. On the basis of the analysis [3] we discuss here two examples of the GMFV models: the large tan β limit of the 2HDM(II) and of the MSSM, in which the CKM matrix is the only source of flavour and CP violation (see e.g. [4]).