相关论文: First observation of KL -> pi+- e-+ nu e+ e-
We report on a new measurement of the branching ratio B(KL->pi0 gamma gamma)using the KTeV detector. We reconstruct 1982 events with an estimated background of 608, that results in B(KL -> pi0 gamma gamma) = (1.29 +/- 0.03(stat) +/-…
By analyzing $e^+e^-$ annihilation data corresponding to an integrated luminosity of 2.93 $\rm fb^{-1}$ collected at a center-of-mass energy of 3.773 GeV with the \text{BESIII} detector, the first observation of the semileptonic decays…
The preliminary result on the absolute branching ratio of the decay K+ to pi+ pi0 (gamma), obtained by the KLOE experiment operating at the DAPHNE Frascati Phi-Factory, is presented.
We observe signals for the decays psi(3770)--> X J/psi from data acquired with the CLEO detector operating at the CESR e^+e^- collider with sqrt{s}=3773 MeV. We measure the following branching fractions B(psi(3770)--> XJ/psi) and…
We calculate the momentum dependent form factors of $P \to \gamma^* \gamma^*$($P=\pi^{0}, \eta$) within the light-front quark model. Using the form factors, we examine the decays of $P \to l^+ l^-$, $P \to l^+ l^- \gamma$ and $P \to l^+ l^-…
We report the observation of the decay $B^- \to D_{\pi^+\pi^-\pi^0} K^-$, where $D_{\pi^+\pi^-\pi^0}$ indicates a neutral $D$ meson detected in the final state $\pi^+\pi^-\pi^0$, excluding $K_S \pi^0$. This doubly Cabibbo-suppressed decay…
A new measurement of the absolute branching ratio BR($K^\pm \to \pi^\pm \pi^0 \pi^0$) with the KLOE detector at the DA$\Phi$NE $e^+e^-$ collider is presented, based on a sample of $\sim 3.3\times 10^7$ charged kaons tagged events, produced…
E865 at the Brookhaven National Laboratory AGS collected about 70,000 K+e3 events with the purpose of measuring the K+e3 branching ratio relative to the observed K+ ->pi+pi0, K+ -> pi0 mu+ neutrino, and K+ -> pi+ pi0 pi0 decays. The pi0 in…
E865 at the Brookhaven National Laboratory AGS collected about 70,000 K+(e3) events with the purpose of measuring the relative K+(e3) branching ratio. The pi0 in all the decays was detected using the e+e- pair from pi0 -> e+e-gamma decay…
We have studied hadronic tau decay modes involving an eta meson using 490 fb^{-1} of data collected with the Belle detector at the KEKB asymmetric-energy e+e- collider. The following branching fractions have been measured: B(tau- -> K- eta…
The amplitudes of $K \rightarrow \pi \gamma^* \rightarrow \pi e^+e^-$ and $K \rightarrow \pi \pi \gamma$ decays have been calculated within chiral Lagrangian approach including higher-order derivative terms and meson loops. The…
With the full $\babar$ data sample of 465 million BaBar pairs, we observe the decays B+- ->phi(1020) K_1(1270)+- and B+- ->phi(1020) K_2*(1430) +-. We measure the branching fractions (6.1+-1.6+-1.1)\times 10^{-6} and (8.4+- 1.9+- 0.9)\times…
We report a measurement of the branching fraction for the decay $B^+ \to \rho^+\pi^0$ based on a 140 ${\rm fb}^{-1}$ data sample collected with the Belle detector at the KEKB asymmetric $e^+e^-$ collider. We measure the branching fraction…
The absolute branching ratio of the $K^+ \rightarrow \pi^+\pi^-\pi^+(\gamma)$ decay, inclusive of final-state radiation, has been measured using $\sim$17 million tagged $K^+$ mesons collected with the KLOE detector at DA$\Phi$NE, the…
Based on a sample of 225.3 million J/\psi events accumulated with the BESIII detector at the BEPCII, the decays of \eta' to pi+pi-l+l- are studied via J/\psi to \gamma\eta'. A clear \eta' signal is observed in the pi+pi-e+e- mass spectrum,…
Decays $K^{+} \rightarrow \mu^{+}\nu_{\mu} \nu \bar \nu$ and $K^{+}\rightarrow e^{+}\nu_{e} \nu \bar \nu$ are examined to the leading order in momenta in the framework of Chiral Perturbation Theory. Predictions of the Standard Model for the…
Simple dynamics, few available decay channels, and highly controlled radiative and loop corrections, make pion and muon decays a sensitive means of exploring details of the underlying symmetries. We review the current status of the rare…
We investigate the mechanism of K+ -> pi+ l+ l- (l= e, mu) decays in which a virtual photon is emitted either from the incoming K+ or the outgoing pi+. We point out some inconsistencies with and between two previous calculations, discuss…
We present a new measurement of the branching ratio of the decay K_L -> pi e nu gamma (Ke3g) with respect to K_L -> pi e nu (Ke3), and the first study of the photon energy spectrum in this decay. We find BR(Ke3g, E*g>30 MeV, theta*_eg>20…
The first observation of the decay Bs -> D0bar K- {\pi}+ is reported. The analysis is based on a data sample, corresponding to an integrated luminosity of 1.0 fb-1 of pp collisions, collected with the LHCb detector. The branching fraction…