出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：The rare kaon decays KL →p 0nn¯ , K+ →p+nn¯ , KL →p 0e+e− and KL →p 0m+m− are theoretically
very clean and, being strongly CKM suppressed, highly sensitive to New Physics (NP).
Recent Flavour Physics analyses show that they represent unique probes for revealing NP effects
and to provide information on the NP flavour structure. After a brief discussion of the main properties
that make rare K decays so promising and of the basic ideas of the most interesting NP
models, we review the results of recent phenomenological analyses both within and beyond the
framework of Minimal Flavour Violation (MFV), where the sources of flavour violation are the
same as in the Standard Model. Within MFV we present the expectations found for rare K decays
from a model-independent analysis and in three MFV models: the Littlest Higgs (LH) model, the
(extra-dimension) Appelquist-Cheng-Dobrescu model and the Minimal Supersymmetric Standard
Model (MSSM) with MFV. Beyond MFV, we discuss the results recently found within the
MSSM (without MFV), the LH model with T-parity (LHT) and the 3-3-1 (Z′) model. While in
MFV models only small (< 30%) NP effects are allowed in the branching ratios of KL →p 0nn¯ ,
K+ →p+nn¯ , KL →p 0e+e− and KL →p 0m+m−, beyond MFV, in particular in the MSSM and
in the LHT model, large (up to an order of magnitude) enhancements w.r.t. the SM turn out to be
possible.
