Observable Neutron-Anti-Neutron Oscillation, Baryogenesis and High Scale Seesaw

Seesaw mechanism has been a dominant paradigm in the discussion of neutrino masses. I discuss how this idea can be tested via a baryon number violating process such as $N-\bar{N}$ oscillation. Since the expected seesaw scale is high and the $N-\bar{N}$ amplitude goes like $M^{-5}_{R}$, one might think that this process is not observable in realistic seesaw models for neutrino masses. In this talk I show that in supersymmetric models, the above conclusion is circumvented leading to an enhanced and observable rate for $N-\bar{N}$ oscillation. I also discuss a new mechanism for baryogenesis in generic models for neutron-anti-neutron oscillation and show how the requirement of adequate baryogenesis can put an upper limit on the neutron-anti-neutron oscillation time.