Theory of rare K decays

I review rare kaon decays. I introduce the flavor problem and possible solutions. Very rare kaon decays like K → πvv¯ are very important to this purpose: we study also K → πl+l-, K → ππee where chiral dynamics is important to disentangle short distance effects. We discuss also the decays K0 → μ+μ-, which have received recently some attention due to the measurement by LHCB.

Kaon decays at KLOE-2

I review kaon decays. I introduce the flavor problem and possible solutions. Very rare kaon decays like [see formula in PDF] are very important to this purpose: we study also [see formula in PDF] where chiral dynamics is important to disentangle short distance effects. We have also studied lepton flavor (universality) violation in rare kaon decays and the Bardeen Buras Gerard approach to describe the [see formula in PDF] form factor.

NEUTRINO MASS AND GRAND UNIFICATION OF FLAVOR

The problem of understanding quark mass and mixing hierarchies has been an outstanding problem of particle physics for a long time. The discovery of neutrino masses in the past decade, exhibiting mixing and mass patterns so very different from the quark sector has added an extra dimension to this puzzle. This is specially difficult to understand within the framework of conventional grand unified theories which are supposed to unify the quarks and leptons at short distance scales. In the paper, I discuss a recent proposal by Dutta, Mimura and this author that appears to provide a promising way to resolve this puzzle. After stating the ansatz, we show how it can be realized within a SO(10) grand unification framework. Just as Gell-Mann's suggestion of SU(3) symmetry as a way to understand the hadronic flavor puzzle of the sixties led to the foundation of modern particle physics, one could hope that a satisfactory resolution of the current quark-lepton flavor problem would provide fundamental insight into the nature of physics beyond the standard model.