Related papers: Scalar and Tensor Couplings in Kaon Decays
Pion-kaon ($\pi K$) pairs occur frequently as final states in heavy-particle decays. A consistent treatment of $\pi K$ scattering and production amplitudes over a wide energy range is therefore mandatory for multiple applications: in…
Measuring the rate at which the long-lived, neutral kaon decays into a neutral pion, neutrino, and anti-neutrino allows physicists an opportunity to test precise predictions made by the Standard Model. Differences between theoretical…
We quantify the important effect of strong final state interactions in the weak $K\to 2\pi$ amplitudes, using the measured $\pi$-$\pi$ phase shifts with J=0 and $I=0,2$. The main results of this analysis, with their implications for…
We review recent progress in calculating kaon spectrum, pseudoscalar meson decay constants, $B_K$, $\epsilon'/\epsilon$, $K\to \pi\pi$ matrix elements, kaon semileptonic form factors, and moments of kaon distribution amplitudes on the…
Numerous recent measurements of kaon decays are described, with an emphasis on results offering constraints on chiral perturbation theory calculations. An up-to-date estimate of |Vus|f+(0) based on semileptonic kaon decay rates is…
The E814-collaboration has found a component of very low $m_t$ $K^+$ mesons with a slope parameter of $T \sim 15 \, \rm MeV$. We will present a scenario which explains the observed slope parameter and which allows us to predict the expected…
Measurements of the dynamical correlations between neutral and charged kaons in central Pb-Pb collisions at $\sqrt{s_{NN}} = 2.76$ TeV by the ALICE Collaboration display anomalous behavior relative to conventional heavy-ion collision…
We present a comprehensive analysis of low-energy signals of hypothetical scalar leptoquark interactions in lepton and kaon transitions. We derive the most general effective four-fermion Lagrangian induced by tree-level scalar leptoquark…
The evaluation, systematic analysis and numerical study of the semileptonic $\tau$-lepton decays with two mesons in the final state has been made in the frame of the standard model extended by right handed neutrinos. In the analysis,…
A review of the present experimental status of the rates and the Dalitz-plot slope parameters in CP conserving K->2\pi and K->3\pi decays is given. The corresponding isospin amplitudes have been determined by a common fit to the recent…
The rare kaon decay $K^+ \to \pi^+\ell^+\ell^-$ offers insights into Standard Model (SM) physics and beyond. Driven by vector form factor in the SM, it can also probe non-standard contributions. In this letter we study the scalar…
We discuss the possibilities of extracting the constraints on New Physics by using the current data on the leptonic and semileptonic decays of pseudoscalar mesons. In doing so we use a general low energy Lagrangian that besides the vector…
We review the physics of purely leptonic decays of $\pi^\pm$, $K^\pm$, $D^{\pm}$, $D_s^\pm$, and $B^\pm$ pseudoscalar mesons. The measured decay rates are related to the product of the relevant weak-interaction-based CKM matrix element of…
Neutrino-electron scattering is a purely leptonic fundamental interaction and therefore provides an important channel to test the Standard Model, especially at the low energy-momentum transfer regime. We derived constraints on neutrino…
This paper summarizes some recent progress and future perspectives in the experimental investigation of the Standard Model (and physics beyond it) using charged kaon decays, except for the important mode K+ -> pi+ nu nubar discussed in…
We point out kaon decays to multiple charged leptons as a novel probe of light dark particles $X$. Previously neglected channels, such as $K^+\to \pi^+ \left(XX \to 2(e^+e^-)\right)$, $K_L\to \pi^0 \left( XX \to 2(e^+e^-)\right)$, and…
First full next-to-leading order analytical results in Chiral Perturbation Theory for the charged Kaon K -> 3 pi slope g and decay rates CP-violating asymmetries are presented. We discuss the constraints that a measurement of these…
Leptonic and semileptonic kaon decays represent till now the golden modes for the extraction of the Cabibbo angle from experiments, provided the relevant hadronic quantities, namely the ratio of the kaon and pion leptonic decay constants,…
The E814-collaboration has found a component of very low $m_t$ $K^+$ mesons with a slope parameter of $T \sim 15 \, \rm MeV$. We will present a scenario which explains the observed slope parameter and which allows us to predict the expected…
Large neutrino event numbers in future experiments measuring coherent elastic neutrino nucleus scattering allow precision measurements of standard and new physics. We analyze the current and prospective limits of a light scalar particle…