Related papers: Cusps in eta' --> eta pi pi decays
Using 281 pb^-1 of data collected with the CLEO-c detector, we present new measurements of Cabibbo-suppressed decays of D0 and D+ mesons to eta and eta' final states. We make first observations of D0-->eta'pi0, eta eta, eta eta', and eta…
In e+e- collisions recorded using the CLEO II.V detector we have studied the Cabibbo suppressed decay of D0 -> pi+pi-pi0 with the initial flavor of the D0 tagged by the decay D*+ -> D0pi+. We use the Dalitz-plot analysis technique to…
Recently, the Belle and LHCb Collaborations have measured the $\Lambda^+_c \to p K^- \pi^+$ decay and reported the $p K^-$ invariant mass distribution, which shows a clear cusp structure around the $\eta \Lambda$ threshold. In this work, we…
Based on a $J/\psi$ data sample of $7.8 \times 10^6$ events at BESI, the decay of $ J/\psi \to \bar{K}^*(892)^0 K^+ \pi^-$ is studied and a low mass enhancement, which is believed not coming from the phase space effect or background, is…
Using 7.33 fb$^{-1}$ of $e^+e^-$ collision data collected by the BESIII detector at center-of-mass energies between 4.128 and 4.226~GeV, we observe for the first time the decay $D^{\pm}_s\to \omega\pi^{\pm}\eta$ with a statistical…
We use a twice-subtracted partial-wave dispersion relation in the elastic unitarity approximation for final-state interactions to study the amplitude for the delta I = 1/2 CP-conserving weak process K+spurion->pi+pi. We use a simple…
Various decays of eta and eta-prime are investigated within the framework of U(3) chiral effective field theory in combination with a relativistic coupled-channels approach. Final state interactions are included by deriving s- and p-wave…
For coupled channels $D^0K^+$, $D^+K^0$, $D_s^+\eta$, and $D_s^+\pi^0$, the $S$-wave scattering amplitudes are constructed taking into account the mixing of the isoscalar resonance $D^*_{s0}(2317)^+$ with nonresonance amplitudes with…
After summarizing the current theoretical status of the four-body decay B --> K^*(--> K pi) mu^+ mu^-, we apply the formalism of spin-symmetries to the full angular distribution, including the S-wave part involving a broad scalar resonance…
We consider what constraints unitarity and CPT invariance yield on the strong and electromagnetic phases entering K -> pi pi decay. In particular, we show that the relative size of the electromagnetically-induced changes in the I=0 and I=2…
The decay K_L -> pi0 e+ e- is being searched for as a signal of direct Delta S = 1 CP violation. We provide a thorough updating of the analysis of the three components of the decay: 1) Direct CP violation, 2) CP violation through the mass…
The known ratio of the branching fractions for D_s^* --> D_s pi^0 and D_s^* --> D_s gamma may be used to extract the coupling of eta mesons to strange quarks once the value of the pi^0-eta mixing angle is known. This requires that realistic…
We discuss all contributions from Zweig-rule-satisfying SU(3)-breaking final state interactions (FSIs)in the B -> PP decays (neglecting charmed intermediate states), where PP=pi pi, pi K, KK, pi eta (eta'), and K eta (eta'). First, effects…
The $\eta \to \pi^+ \pi^- \pi^0 \gamma$ decay is discussed in the general context of Chiral Perturbation Theory (ChPT), assuming that the low--energy constants (counter--terms) are saturated by vector-meson resonances. The $\eta \to \pi^+…
An overview is given of Chiral Perturbation Theory and various applications to eta decays. In particular, the main decay $\eta\to3\pi$ is discussed at the one-loop level, and estimates of the higher order corrections are given. The…
We have searched with the KLOE detector for the P and CP violating decay eta -> pi^+pi^- in a sample of 1.55 x 10^7 eta's from the decay phi -> eta gamma of phi mesons produced in e+e- annihilations at DAFNE. No signal is found. We obtain…
Using 58 million $J/\psi$ events taken with the BESII detector, a search for $eta_{c}$ CP violating decays into $\pi\pi$ and $\bar{K}K$ has been performed. No clear $eta_{c}$ is observed, and upper limits for $B(eta_{c}->\pi \pi)$and…
Using a sample of 3 million psi(2S) decays recorded by the CLEO detector, we study three-body decays of the chi_c0, chi_c1, and chi_c2 produced in radiative decays of the psi(2S). We consider the final states pi+ pi- eta, K+ K- eta, p p-bar…
We present a model-independent analysis of $K^+\to\pi^+\ell^+\ell^-$ and $K_S\to\pi^0\ell^+\ell^-$ decays, including $K\to 3 \pi$ unitarity corrections and a general decomposition of the dispersive amplitude. From the existing data on…
Quark condensate and pseudoscalar decay constant in the chiral limit are the principal order parameters of spontaneous chiral symmetry breaking in QCD. Yet their three flavor values are still only weakly constrained by analyses using…