Lepton flavor violation at LEP II and beyond

摘要

At present, two fundamental mysteries in particle physics are the origins of electroweak symmetry breaking and the fermion mass matrices. The experimental discovery of superpartners would represent enormous progress in the understanding of electroweak symmetry breaking, but would it also allow progress on the flavor problem. To date, nearly all experimental studies of supersymmetry have ignored the possibility of flavor mixings in the sfermion sector. However, since all superpartners must be given masses, all supersymmetric theories necessarily allow for the possibility of new flavor mixings beyond the standard model. In addition, there are now many supersymmetric theories of flavor, which predict a wide variety of superpartner flavor mixings. In this study, the author examines the possibility of measuring these mixings at LEP II and the Next Linear Collider (NLC). Rare flavor changing processes, such as (mu) (yields) e(gamma), (tau) (yields) (mu)(gamma), (tau) (yields) e(gamma), b (yields) s(gamma), and neutral meson mixing, already provide important constraints on the sfermion flavor mixings through the virtual effects of superpartners. However, as will be seen below, once superpartners are discovered, it will be possible to probe these mixings much more powerfully by directly observing the change in flavor occurring at the superpartner production and decay vertices.