Related papers: Kaon Flavour Physics Strikes Back

NA62 is a fixed-target kaon experiment at the CERN SPS. The recent measurement of the ultra-rare decay $K^+\to\pi^+\nu\bar\nu$, based on data collected between 2016 and 2024 is reported. The measurement is compatible with previous…

The rare decays of a kaon into a pion and a charged lepton/antilepton pair proceed via a flavour changing neutral current and therefore may only be induced beyond tree level in the Standard Model. This natural suppression makes these decays…

We analyse the rare processes $K \to \pi\nu\bar\nu$ in view of the recent hints of violations of Lepton Flavour Universality (LFU) observed in B meson decays. If, as suggested by present data, the new interactions responsible for LFU…

A decade long search for the rare kaon decay to pi^+nunu-bar has been pursued by E787. Two signal events are observed, giving a measurement of the branching ratio Br(K^+ -> PI^+NUNU-BAR)=1.57^+1.75_-0.82 x 10^-10 and a constraint on the…

Kaon physics can test new-physics effects in leptonic or semileptonic decays. A unitarity test of the first row of the CKM mixing matrix is obtained from the precision measurements of Kl3 widths for K{\pm}, KL, and (unique to KLOE) KS. The…

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…

Inspired by the potential prospects of high-luminosity dedicated colliders and the high enthusiasms in searching for new physics in the flavor sector at the intensity frontier, the ${\Upsilon}(1S)$ ${\to}$ $D^{-}{\pi}^{+}$,…

The KOTO experiment was designed to observe and study the K$^{0}_{L} \rightarrow$ $\pi^{0}\nu\bar{\nu}$ decay at J-PARC. The Standard Model (SM) prediction for the process is (3.0 $\pm$ 0.3) x 10$^{-11}$ with small uncertainties. This…

The NA48/2 Collaboration at CERN has accumulated and analysed unprecedented statistics of rare kaon decays in the $K_{e4}$ modes: $K_{e4}(+-)$ ($K^\pm \to \pi^+ \pi^- e^\pm \nu$) and $K_{e4}(00)$ ($K^\pm \to \pi^0 \pi^0 e^\pm \nu$) with…

The ratio $R_K=\frac{\Gamma(K\to e \nu_{e} (\gamma))}{\Gamma(K\to \mu \nu_{\mu} (\gamma))}$ of leptonic decay rates provides a golden probe for testing the structure of the weak interactions because it can be predicted with high accuracy…

A systematic analysis of New Physics impacts on the rare decays KL to pi0 l+ l- is performed. Thanks to their different sensitivities to flavor-changing local effective interactions, these two modes could provide valuable information on the…

We searched for the $CP$-violating rare decay of neutral kaon, $K_{L} \to \pi^0 \nu \overline{\nu}$, in data from the first 100 hours of physics running in 2013 of the J-PARC KOTO experiment. One candidate event was observed while…

We discuss some recent lattice results on a few selected hadronic quantities relevant for heavy flavour phenomenology and present some recent theoretical developments. We put the emphasis on the challenges, which have to be faced, on the…

The LHCb experiment has the potential, during the 2010-11 run, to observe the rare decay $B^0_s\to \mu^+\mu^-$ or improve significantly its exclusion limits. This study will provide very sensitive probes of New Physics (NP) effects. High…

The rare four-fold decay $B_s \to K^*(\to K\pi)\mu^+\mu^- $, governed by the flavor-changing neutral current transition $b \to d\mu^+\mu^-$, provides a sensitive probe for testing the Standard Model (SM) and investigating signatures of new…

We summarize the theoretical virtues of the rare K -> pi nu nu-bar decays and emphasize the unique role of KL -> pi0 nu nu-bar in probing the nature of physics beyond the Standard Model, in particular concerning possible new sources of CP…

We review the main aspects of Flavour Physics and CP Violation in the Standard Model. After presenting a grand view of the field including a Master Formula for weak decays we discuss i) Standard analysis of the unitarity triangle, ii) The…

Kaon physics is at an important experimental juncture with respect to the ongoing measurements of several observables. This work will build on the existing status by formulating different phenomenological analyses corresponding to different…

The CERN NA62 experiment uses a novel "kaon decay-in-flight" technique to observe $K^+ \to \pi^+ \nu \overline{\nu}$. The preliminary result based on the analysis of the full 2016 dataset will be presented. In agreement with the Standard…

The decays and mixing of $K$ mesons are remarkably sensitive to the weak interactions of quarks and leptons at high energies. They provide important tests of the standard model at both first and second order in the Fermi constant $G_F$ and…