Related papers: Replay to hep-ph/0606266
The $e^+e^-\to\eta\gamma$ cross section has been measured in the center-of-mass energy range 1.07--2.00 GeV using the decay mode $\eta\to 3\pi^0$, $\pi^0\to \gamma\gamma$. The analysis is based on 36 pb$^{-1}$ of integrated luminosity…
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…
The gradient expansion of the kinetic energy functional, when applied for atoms or finite systems, usually grossly overestimates the energy in the fourth order and generally diverges in the sixth order. We avoid the divergence of the…
The decay rates for $B^0 \to K^+ \pi^-$, $B^+ \to K^0 \pi^+$, and the charge-conjugate processes were found to provide information on the weak phase $\gamma \equiv {\rm Arg}(V_{ub}^*)$ when the ratio $r$ of weak tree and penguin amplitudes…
This work is devoted to the study of discrete ambiguities. For parametrized potentials, they arise when the parameters are fitted to a finite number of phase-shifts. It generates phase equivalent potentials. Such equivalence was suggested…
An analysis of electromagnetic corrections to the (dominant) octet K -> pi pi hamiltonian using chiral perturbation theory is carried out. Relative shifts in amplitudes at the several per cent level are found.
From a sample of $1172 \pm 61$ $D^+ \to \pi^- \pi^+ \pi^+$ decay, we find $\Gamma (D^+ \to \pi^- \pi^+ \pi^+) / \Gamma (D^+ \to K^- \pi^+ \pi^+) = 0.0311 \pm 0.0018 ^{+0.0016}_{-0.0026}$. Using a coherent amplitude analysis to fit the…
The dynamics of the process $ e^+e^- \to \pi^+\pi^-\pi^0 $ is studied in the energy region from 1.15 to 2.00 GeV using data accumulated with the SND detector at the VEPP-2000 $e^+e^-$ collider. The Dalitz plot distribution and $\pi^+\pi^-$…
We perform a theoretical study based on dispersion relations of the reaction \gamma\gamma\to \pi^0\pi^0 emphasizing the low energy region. We discuss how the f_0(980) signal emerges in \gamma\gamma\to \pi\pi within the dispersive approach…
Unconstrained partial-wave amplitudes obtained at discrete energies from fits to complete sets of experimental data may not vary smoothly with energy, and are in principle non-unique. We demonstrate how this behavior can be ascribed to the…
The scalar -- isoscalar pi-pi phase shifts are analysed using a separable potential model of three coupled channels (pipi, KK and an effective 2pi2pi system). Model parameters are fitted to two sets of solutions obtained in a recent…
Various strategies for extracting or constraining the weak phase gamma with controlled theoretical uncertainties are reviewed. Measurements of the rates for the hadronic decays B^+- -> pi K provide largely model-independent information on…
A partial-wave analysis of 9082 eta pi+ pi- n events produced in the reaction pi- p --> eta pi+ pi- n at 18.3 GeV/c has been carried out using data from experiment 852 at Brookhaven National Laboratory. The data are dominated by J^{PC} =…
This work presents the results of a revised analysis of the low-energy (pion laboratory kinetic energy T(sub pi) < 100 MeV) pi+ p data using recently obtained electromagnetic corrections. The measurements are analyzed assuming extended…
In this talk we present an interpretation for the experimental data available on two different processes, namely, $J/\Psi \to \phi \pi^+ \pi^-$, $J/\Psi\to \gamma \omega \phi$, which seem to indicate existence of two new resonances with the…
Using dispersion relation technique and experimental data, a coupled channel analysis on $\gamma\gamma\to\pi\pi$ process is made. Di-photon coupling of $f_0(600)$ and $f_0(980)$ resonances are extracted and their dynamical properties are…
We calculate the s-wave strong interaction $\Lambda$$\pi$ phase shift at the $\Xi$ mass taking into account contributions from the ${{\frac{1}{2}}}^{-}$ and ${{\frac{3}{2}}}^{-}$ $\Sigma$ resonances. We find the S-wave phase shift to be…
The charge asymmetry in the process $e^+e^-\to \pi^+\pi^-\pi^0\gamma$ is studied for photons with energies $\nu\ll\sqrt{s}$. The longitudinal polarization of electrons (positrons) is taken into account. The asymmetry arises due to…
We postulate that the Fermi function should be derived from the amplitude, not from the solution of the Dirac equation, in the quantum field theory. Then, we obtain the following results. 1, We give the amplitude and the width of the…
In a previous paper, some deviations were found in the O(p^6) low-energy constants that contribute to the pi pi-scattering lengths. This work completes the study of all the relevant couplings (r_1, ... r_6, r_S2). We also perform a…