CP Violation and FCNC in the Third Family from Effective Supersymmetry

I discuss a " more minimal " modification of the minimal supersymmetric standard model, in which supersymmetry breaking is connected with the physics of flavor. Flavor Changing Neutral Currents (FCNC) for the first two families are suppressed, and for the third family may be of comparable size to the FCNC in the Standard Model. Modifications of the Minimal Standard Model are haunted by a fundamental dichotomy 1 : namely that in most extensions, Flavor Changing Neutral Current (FCNC) constraints are naturally satisfied only if the new physics scale is above 10–1000 TeV, whereas natural electroweak symmetry breaking requires new physics below ∼ 1 TeV. In table 1 I contrast the virtues and omissions of the Standard Model with two popular extensions: the Minimal Supersymmetric Standard Model (MSSM) with soft supersymmetry breaking, and Technicolor. On the left I have listed various experimental observations that a good theory should explain. It is clear that all these models have many shortcomings, however each of them explains at least one experimental fact in a way that is so beautiful it is hard to believe nature would not make use of it. Now I would like to discuss what features of each of these models makes them so successful, and how one might put them together in a single theory. 2 1. The observed spectrum and couplings Both the Standard Model and the MSSM are very succesful at accomodating the observed fermion masses, mixings, and couplings to the weak gauge bosons, and the key to this success is a fundamental Higgs scalar. Here we should borrow solutions from both the MSSM and from technicolor. Weak scale supersymmetry naturally stabilizes the value of the weak scale against perturbative quantum corrections, 3 and Dynamical Supersymmetry Breaking 4 (DSB) can explain why this scale is so far below the Planck scale, in a manner analogous to the dynamical electroweak symmetry breaking of Technicolor. 5