Then, one can express all the relevant observables as a function of the two remaining parameters, ρ and η , and check whether there is a range in the ρ − η plane that is consistent with all measurements. The list of observables includes the following: The resulting constraints are shown in Fig. 1. The consistency of the various constraints is impressive. In particular, the following ranges for ρ and η can account for all the measurements [5]: One can make then the following statement [7–9]: Very likely, flavor violation and CP violation in flavor changing processes are domi- nated by the CKM mechanism. One can actually go a step further, and allow for arbitrary new physics in all flavor changing processes except for those that have contributions from SM tree diagrams. Then, one can quanti- tatively constrain the size of new physics contributions to processes such as neutral meson mixing. We do so in the next section. In order to describe NP effects in flavor physics we can follow two main strategies: (i) build an explicit ultraviolet completion of the model, and specify which are the new fields beyond the SM ones, or (ii) analyse the NP effects using a generic effective-theory approach, or integrating-out the new heavy fields. The first approach is more predictive, but also more model dependent. We 5 III. MODEL INDEPENDENT CONSTRAINTS ρ = +0 . 135 +0 . 031 − 0 $_{016}$, η = +0 . 349 ± 0 . 017 . (2.14) • The rates of inclusive and exclusive charmless semileptonic B decays depend on | V$_{ub}$ | 2 ∝ ρ 2 + η $^{2}$; • The CP asymmetry in B → ψK$_{S}$ , S$_{B}$$_{→}$$_{ψK}$ = sin 2 β = 2 η (1 − ρ ) (1 − ρ ) $^{2}$+ η 2 ; • The rates of various B → DK decays depend on the phase γ , where e iγ = ρ + iη √ ρ $^{2}$+ η $_{2}$; • The rates of various B → ππ, ρπ, ρρ decays depend on the phase α = π − β − γ ; • The ratio between the mass splittings in the neutral B and B$_{s}$ systems is sensitive to | V$_{td}$/V$_{ts}$ | 2 = λ $^{2}$[(1 − ρ ) 2 + η $^{2}$]; • The CP violation in K → ππ decays, ϵ$_{K}$ , depends in a complicated way on ρ and η .