摘要: 5D UED is not automatically minimally flavor violating. This is due to flavor asymmetric
counter-terms required on the branes. Additionally, there are likely to be
higher dimensional operators which directly contribute to flavor observables. We
document a mostly unsuccessful attempt at utilizing localization in a flat extra dimension
to resolve these flavor constraints while maintaining KK-parity as a good
quantum number. It is unsuccessful insofar as we seem to be forced to add brane
operators in such a way as to precisely mimic the effects of a double throat warped
extra dimension. In the course of our efforts, we encounter and present solutions to
a problem common to many extra dimensional models in which fields are “doubly
localized:” ultra-light modes. Under scrutiny, this issue seems tied to an intrinsic
tension between maintaining Kaluza-Klein parity and resolving mass hierarchies via
localization