Bounds on the unitarity triangle, sin 2 beta and K ->pi nu<nu>over bar decays in models with minimal flavor violation - art. no. 115010

We present a general discussion of the unitarity triangle from epsilon (K), DeltaM(d,s) and K --> pi nu<(<nu>)over bar> in models with minimal flavor violation (MFV), allowing for arbitrary signs of the generalized Inami-Lim functions F-tt and X relevant for (epsilon (K), DeltaM(d,s)) and K --> pi n u<(<nu>)over bar>, respectively. In the models in which F-tt has a sign opp osite to the one in the standard model, i.e. F-tt<0, the data for (<epsilon >(K), DeltaM(d,s)) imply an absolute lower bound on the B-d --> psiK(S) CP asymmetry a(psi KS) of 0.69, which is substantially stronger than 0.42 aris ing in the case of F-tt > 0. An important finding of this paper is the obse rvation that for given Br(K+ --> pi (+) nu<(<nu>)over bar>) and a(psi KS) o nly two values for Br(K-L --> pi (0) nu<(<nu>)over bar>), corresponding to the two signs of X, are possible in the full class of MFV models, independe ntly of any new parameters arising in these models. This provides a powerfu l test for this class of models. Moreover, we derive absolute lower and upp er bounds on Br(K-L --> pi (0)nu<(<nu>)over bar>) as functions of Br(K+ --> pi (+) nu<(<nu>)over bar>). Using the present experimental upper bounds on Br(K+ --> pi (+) nu<(<nu>)over bar>) and \V-ub/V-cb\, we obtain the absolu te upper bound Br(K-L --> pi (0) nu<(<nu>)over bar>)<7.1 X 10(-10) (90% C.L .).