Related papers: K_{e3} decays and CKM unitarity
We report on results of a search for the decay mode K_L -> pi^0 gamma e^+ e^- conducted by the E162 experiment at KEK. We observed no events and set a 90% confidence level upper limit of Br(K_L -> pi^0 gamma e^+ e^-)< 7.1x10^{-7} for its…
A sample of 3984 candidates of the $K^+\to\pi^+\gamma\gamma$ decay, with an estimated background of $291\pm14$ events, was collected by the NA62 experiment at CERN during 2017-2018. In order to describe the observed di-photon mass spectrum,…
We present a measurement of the branching fraction and the longitudinal polarization fraction of $B^{0}\rightarrow\rho^+\rho^-$ decays, as well as the time-dependent $CP$ violating parameters in decays into longitudinally polarized…
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…
A large low-background sample of events (10300) has been collected for the rare decay of kaons in flight K+ -> pi+ e+ e- by experiment E865 at the Brookhaven AGS. The decay products were accepted by a broad band high-resolution charged…
The fully differential angular distribution for the rare flavor-changing neutral current decay {\bar B}_d^0 -> {\bar K}^{*0} (-> K^- \pi^+) e+ e- is studied. The emphasis is placed on accurate treatment of the contribution from the…
We present the status of the measurement of the CKM CP-violating phase gamma (phi3) performed using B->D(*)K(*) decays. We review and compare the main experimental results.
We present precise theoretical predictions for the absolute branching fractions of $\Lambda_c^+ \to \Lambda \ell^+ \nu_\ell\,(\ell=e,\mu)$ decays in the covariant confined quark model. This study is motivated by two recent and accurate…
We analyse the $\overline B_s^0\to K^+l^-\bar \nu$ and $\overline B_s^0\to K^{*+}(\to K\pi) \ell^-\bar \nu$ decays that are valuable for extracting the CKM matrix element $|V_{ub}|$. We calculate the differential and integrated partial…
Precise measurements of semileptonic kaon decay rates at KLOE provide the measurement of the CKM mixing matrix element \vus\ and information about lepton universality. Leptonic kaon decays provide an independent measurement of…
We consider the exclusive $P_{\ell 4}$ decays, $P\to (P_1P_2)_V\ell \nu_{\ell}$, where the subindex $V$ means that the invariant mass of the pseudoscalar pair is taken within a small window around the mass of the vector meson $V$. Pole…
Some selected topics involving photonic and leptonic rare B decays are reviewed. The interest in their measurement for the CKM phenomenology is underlined. They are also potentially interesting in searching for physics beyond the standard…
The ten nonleptonic weak decays $K \to 2\pi$, $K \to 3\pi$, $K_L \to 2\gamma$, $K_S \to 2\gamma$, $K_L \to \pi^\circ 2\gamma$, are predicted for a chiral pole model based on the linear sigma model theory which automatically satisfies the…
We present a new measurement of the unitarity triangle angle phi3 using a Dalitz plot analysis of the KsPi+Pi- decay of the neutral D meson produced in B->D(*)K decays. The method exploits the interference between D0 and D0bar to extract…
We have analyzed 1.62 fb$^{-1}$ of $e^{+}e^{-}$ collisions at a center of mass energy $\sim M_{\phi}$ collected by the KLOE experiment at DA$\Phi$NE. This sample corresponds to a production of $\sim$ 1.7 billion of $\ks$ $\kl$ pairs which…
We consider a process $K_{L e5} ( K_{L} \rightarrow \pi^{0} \pi^{0} \pi^{\pm} e^{\mp} \nu )$ as a standard model background to the experiment $K_{L} \rightarrow \pi^{0} \mu^{\pm} e^{\mp}$, which seeks for possible violation of lepton family…
The NA48/2 experiment at CERN reports the first observation of the $K^{\pm} \rightarrow \pi^{0} \pi^{0} \mu^{\pm} \nu$ decay based on a sample of 2437 candidates with 15% background contamination collected in 2003--2004. The decay branching…
We use one-loop chiral perturbation theory to compare potential lattice computations of the K+ --> pi+ pi0 decay amplitude at m_K=2m_pi with the experimental value. We find that the combined one-loop effect due to this unphysical pion to…
The rare $K^\pm\to\pi^\pm\pi^0 e^+e^-$ decay, currently under analysis by the NA48/2 Collaboration, is considered. We have performed two theoretical approaches to calculate the differential decay width -- in the kaon rest frame, where we…
The form factors of the decay K+ --> pi0 e+ nu (K_e3) have been determined from the comparison of the experimental and Monte Carlo Dalitz distributions containing about 10^5 K_e3 events. The following values of the parameters were obtained:…