The supersymmetric flavour and CP problems from a cosmological perspective

The supersymmetric flavour and CP problems can be avoided if the first two generations of sfermions are heavier than a few TeV and approximately degenerate in mass. However using flavour and CP-violating constraints on the third sfermion generation, together with the decoupling of the first two generations, can dramatically affect cosmological predictions such as the relic abundance of stable particles. In particular, we show that if the lightest supersymmetric particle is essentially bino-like then requiring that all flavour changing neutral current and CP-violating processes are adequately suppressed, imposes severe limits on the bino mass, where typically mB̃≳ (200–300) GeV. This leads to difficulties for models implementing the scenario of heavy sfermion masses.