Related papers: Rare K -> pi nu nubar Decays
The estimation of rare K decay matrix-elements from Kl3 experimental data is extended beyond LO in Chiral Perturbation Theory. Isospin-breaking effects at NLO (and partially NNLO) in the ChPT expansion, as well as QED radiative corrections…
Flavour changing neutral current decays are a very sensitive test of the standard model and its extensions. In particular the decay K -> pi nu nubar constitutes a clean way to provide constraints, independent of long distance effects.…
In view of future plans for accurate measurements of the theoretically clean branching ratios Br(K+ -> pi+ nu nu) and Br(KL -> pi0 nu nu), that should take place in the next decade, we collect the relevant formulae for quantities of…
Rare decays of K mesons are reviewed from the perspective of testing the ``ones'' and ``zeros'' of the standard model. Decays K^+ -> pi^+ nu anti-nu and K_L -> pi^0 nu anti-nu probe the one-loop effective Hamiltonian for s -> d nu anti-nu,…
The rare decay KL to pi0mu+mu- has a significant CP-conserving contribution. The reliable theoretical estimation of this piece from the experimental pi0-two photon branching ratio is shortly reviewed. Then, we discuss the exceptional…
A brief review of current results on rare kaon decays, particularly the charged and neutral K-> pi nu nubar channels, is presented along with prospects for future measurements.
The measured B -> pi pi, pi K branching ratios exhibit puzzling patterns. We point out that the B -> pi pi hierarchy can be nicely accommodated in the Standard Model (SM) through non-factorizable hadronic interference effects, whereas the B…
After a brief introduction to the so-called flavour problem, we discuss the role of K -> pi nu nu-bar decays in shedding new light on this issue. In particular, we review the theoretical uncertainties in predicting B(K -> pi nu nu-bar)…
We present an extensive analysis of rare K decays, in particular of the two neutrino modes K+->pi+ nu nu-bar and KL->pi0 nu nu-bar, in the Minimal Supersymmetric extension of the Standard Model. We analyse the expectations for the branching…
An analysis of the rare B decays $B\to K^{(*)}\nu\bar\nu$ is presented both within the SM and beyond. The SM predictions for the branching ratios are updated and uncertainties reduced. For the NP analysis both a model independent approach…
We present an updated analysis of the rare decay $K_{L}\to\pi^{0}\mu^{+}\mu^{-}$ within the Standard Model. In particular, we present the first complete calculation of the two-photon CP-conserving amplitude within Chiral Perturbation…
We review some recent theoretical results on rare kaon decays. Particular attention is devoted to find Standard Model tests. This is theoretically easy in $K\to \pi \nu \bar{\nu}$, while a careful study of the long distance contributions is…
The importance of rare $K$ decays especially in the context of a kaon unitarity triangle (KUT) is emphasized. The decay $K_L \to \pi^0 \nu \bar \nu$ is theoretically very clean but experimentally extremely challenging. The Standard Model…
Over the next years, the Flavour Physics community will be looking for inconsistencies of the Standard Model (SM) by exploiting new and precise measurements. In these ``indirect new physics'' searches, the key strategy is to concentrate on…
Rare Kaon decays and CP violation are important tools to test the Standard Model and its extensions. We describe kaon physics observables testing CP violation and more generally short distance physics. Channels under consideration will be K…
This paper presents the latest results from experiment E787, at Brookhaven National Laboratory, on K+ -> pi nu/nubar and radiative K+ decays. The result for K+ -> pi nu/nubar uses data collected in runs taken during 1995, 1996 and 1997. In…
The supersymmetric contributions to the theoretically clean K+ --> pi+ nu nu bar, KL --> pi0 nu nu bar, KL --> pi0 e+ e- and KL --> pi0 mu+ mu- decays are briefly reviewed. Particular emphasis is laid on the information one could get on the…
We summarize a recent strategy for a global analysis of the B -> pi pi, pi K systems and rare decays. We find that the present B -> pi pi and B -> pi K data cannot be simultaneously described in the Standard Model. In a simple extension in…
Rare K decays provide for very clean tests of the Standard Model, and are especially suited to search for New Physics signal. In this talk, recent progresses in the estimation of long-distance effects induced by light quarks in KL to pi0…
We have observed the rare decay K+ --> pi+ mu+ mu- and measured the branching ratio Gamma(K+ --> pi+ mu+ mu-)/Gamma(K+ --> all) = (5.0 +/- 0.4 (stat.) +/- 0.7 (sys.) +/- 0.6 (theor.)) x 10^{-8}. We compare this result with predictions from…