Related papers: K Rare Decays with NA62
Building on the rare pion and muon decay results of the PIBETA experiment, the PEN collaboration has undertaken a precise measurement of B_{\pi e2} = R^\pi_{e/\mu}, the \pi^+ -> e^+\nu(\gamma) decay branching ratio, at the Paul Scherrer…
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.…
We present a new analysis of the rare decay K_L -> pi0 e+ e- taking into account important experimental progress that has recently been achieved in measuring K_L -> pi0 gamma gamma and K_S -> pi0 e+ e-. This includes a brief review of the…
The $D^+_s\to K^+K^-\mu^+\nu_\mu$ decay is studied based on 7.33 fb$^{-1}$ of $e^+e^-$ collision data collected with the BESIII detector at center-of-mass energies in the range from 4.128 to 4.226 GeV. The absolute branching fraction is…
The quantity R_K = Gamma(K -> e nu)/Gamma(K -> mu nu) studied by the experiment NA62 at CERN is known to probe lepton-flavour violating (LFV) parameters of the Minimal Supersymmetric Standard Model (MSSM). A non-zero parameter…
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 availability of high intensity kaon beams at the CERN SPS North Area gives rise to unique possibilities for sensitive tests of the Standard Model in the quark flavor sector. Precise measurements of the branching ratios for the…
Using a sample of 232 x 10^6 Upsilon(4S)--> B B-bar events collected with the BABAR detector at the PEP-II B-factory we study the decay B- --> [K+ pi-]_D K*- where the K+ pi- is either from a Cabibbo-favored D0-bar decay or…
Precise measurements of the branching ratios for the flavor-changing neutral current decays $K\to\pi\nu\bar{\nu}$ can provide unique constraints on CKM unitarity and, potentially, evidence for new physics. It is important to measure both…
The NA62 experiment is designed to measure the ultra-rare decay $K^+ \rightarrow \pi^+ \nu \bar{\nu}$ branching ratio with a precision of $\sim 10\%$ at the CERN Super Proton Synchrotron (SPS). The trigger system of NA62 consists in three…
We present a preliminary measurement of the CP asymmetry in singly Cabibbo-suppressed D+ -> K-K+\pi+ decays and in the resonant decays D+ -> \phi \pi+ and D+ -> K*0 K+. We use a data sample of 79.9 fb^{-1} recorded by the BABAR detector.…
The decay rate of $\klpgg$ has been measured with the NA48 detector at the CERN SPS. A total of 2558 $\klpgg$ candidates have been observed with a residual background of 3.2%. The branching ratio is determined to be $(1.36 \pm0.03_{(stat)}…
Using a sample of 232 million Upsilon(4S) --> B Bbar events collected with the BABAR detector at the PEP-II B Factory in 1999-2004, we study B- --> D0 K*(892)- decays where K*- --> KS pi- and D0 --> K-pi+, K-pi+pi0, K-pi+pi+pi- (non-CP…
The NA62 experiment at CERN collected a large sample of charged kaon decays with a highly efficient trigger for decays into electrons in 2007. The kaon beam represents a source of tagged neutral pion decays in vacuum. A measurement of the…
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…
The $K_L\to\pi^{\pm}\pi^0e^{\mp}\nu_e(\bar\nu_e)$ decay was investigated with the NA48 detector at CERN SPS using a beam of long-lived neutral kaons. The branching ratio $Br(K_L\to\pi^{\pm}\pi^0e^{\mp}\nu_e(\bar\nu_e))=(5.21\pm…
The decay $K^{-} \to \mu^{-} \bar{\nu} \pi^{0}$ has been studied using in-flight decays detected with ``ISTRA+'' setup operating in the 25 GeV negative secondary beam of the U-70 PS. About 112K events were used for the analysis. The…
In Ref [1] we have presented the results of an exploratory lattice QCD computation of the long-distance contribution to the $K^+\to\pi^+\nu\bar{\nu}$ decay amplitude. In the present paper we describe the details of this calculation, which…
Rare kaon decays provide sensitive tests of new physics. In this work, we focus on scalar and pseudoscalar operators, analysing the $K\to \pi \ell^+\ell^-$ and $K\to \ell^+\ell^-$ decays. We highlight the complementary role of different…
We report a measurement of the branching fraction of $B \to K^{\ast}(892)\ell^+\ell^-$ decays, where $\ell^+\ell^- = \mu^+\mu^-$ or $e^+e^-$, using electron-positron collisions recorded at an energy at or near the $\Upsilon(4S)$ mass and…