We enforce chiral Ward identities on the vertices of the linear σ model to take into account the width of the scalar σ, considered as a true physical resonance. We consider pion scattering at very… (More)

We use SU(3) flavor symmetry to analyze the PP , V P and baryon-antibaryon decays of J/ψ. Both, the SU(3)-invariant and -violating contributions are considered. Particular attention is paid to the… (More)

An experimental study of the wavelength shift of four-wave mixing (FWM) bands as a function of pump power in single-mode photonic crystal fibers pumped at normal dispersion is presented. Three fibers… (More)

An experimental study of the effects of an auxiliary 976 nm pump signal on the four-wave mixing parametric bands generated with a 1064 nm pump in a normal dispersion Er-doped photonic crystal fiber… (More)

We consider the forward-backward pion charge asymmetry for the e + e − → π + π − γ process. In addition to the Bremsstrahlung and the double resonance contributions, we use four different models to… (More)

The ratio Φ → K + K − /K 0 ¯ K 0 is discussed and its present experimental value is compared with theoretical expectations. A difference larger than two standard deviations is observed. We critically… (More)

We address the problem of properly deening the W propagator in the resonance region. Particular attention is paid to the longitudinal piece of this propagator. We also discuss the related… (More)

The generation of correlated photon pairs plays a central role in several quantum mechanics applications, such as quantum information, and cryptography [1]. Correlated photon pairs can be generated… (More)