Related papers: Residual correlations between decay products of $\…
We develop an ansatze of the sigma enhancement of the I=0, L=0 $\pi$-$\pi$ scattering amplitude as arising from a low-energy glueball pole. Using this picture we estimate the $\pi^0\pi^0$ to $\pi^0$ branching ratio for the decays of the…
The decays of $N^*$ and $\Delta^*$ resonances into $N\rho$, $\Delta\pi$ and $N\sigma$ final states are studied in a coupled-channel analysis of data on pion- and photo-induced reactions. Improvements in the fit were observed when new…
We present a study of the $\pi\pi$ scattering amplitude in the $\sigma$ and $\rho$ channels at finite temperature and nuclear density within a chiral unitary framework. Meson resonances are dynamically generated in our approach, which…
A comprehensive analysis of all available data on cross sections and spin-dependent observables for the $\gamma p \to K^+ \Sigma^0(1385)$, $\gamma n \to K^+ \Sigma^-(1385)$, and $\pi^+ p \to K^+ \Sigma^+(1385)$ reactions is performed within…
Dispersion relations---a corollary of unitarity and analyticity---are among the few methods which can be employed to study low energy processes in QCD. In this work we critically revisit the calculation of decay widths of a hypothetical…
We study the dependence of neutrino-induced $\gamma/\pi^0$ production ($\stackrel{ {(-)}}{\nu_\mu} + A \to \stackrel{ {(-)}}{\nu_\mu}(\mu) +\gamma/\pi^0 + X$) on the target nucleus A, at the $\Delta$ resonance mass region. Our conclusion is…
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…
We derive the minimal Fock-state expansions of the pion and the photon wave functions in light-cone formalism, then we calculate the pion-photon and the photon-pion transition form factors of $\gamma ^{\ast}\pi ^{0}\to \gamma $ and $\gamma…
We review recent developments concerning the weak decay of Lambda hypernuclei. New studies covering the mesonic decay channel as well as recent models for the non-mesonic one are discussed and compared with experimental data. The puzzle of…
We calculated the differential cross sections of the processes in which one of the pair created tau particles at an e^+ e^- collider decays into lepton flavor violating final states e.g. tau -> mu gamma, tau -> 3 mu, tau -> mu ee. Using the…
Harvey, Hill, and Hill have found that unexpected interactions involving the nucleon, photon, and weak gauge bosons at low energies emerge from gauging the axial anomaly of QCD under the full electroweak symmetry of the Standard Model (SM).…
We study the effect of the sigma(600) and a_1(1260) resonances in the rho^0 -> pi^+ pi^- gamma decay, within the meson dominance model. Major effects are driven by the mass and width parameters of the sigma(600), and the usually neglected…
We investigate the three-body decays of $\Lambda_c^*(2595)$ and $\Lambda_c^*(2625)$ into $\Lambda_c \pi \pi$ by including a direct process going through the two-pion coupling of $\Lambda_c^*\Lambda_c \pi \pi$ in addition to the sequential…
The ratio of branching ratios in leptonic pion decay $R_{\pi} \equiv (\Gamma(\pi^- \to e \nu_e))/(\Gamma(\pi^- \to \mu \nu_\mu))$ is a powerfully sensitive probe of new interactions beyond the electroweak standard model. This is due to the…
We investigate the scalar resonances in the processes of $D^{0} \rightarrow \pi^{0}\pi^{0}\pi^{0}, \pi^{0}\pi^{0}\eta, \pi^{0}\eta\eta$ decays based on the chiral unitary approach for the final state interaction. We start from singly…
Using as a tool the s-wave approximation (sWA), this work demonstrates that the nonmesonic weak decay transition rates $\Gamma_{n}$ and $\Gamma_{p}$ can be expressed in all hypernuclei up to $^{29}_\Lambda $Si (and very likely in heavier…
We investigate the two-body reaction $\pi^- p \to K^{0} \Lambda$ within the effective Lagrangian approach and the isobar model. In addition to the "background" contributions from $t$-channel $K^*$ exchange, $u$-channel $\Sigma(1192)$ and…
It is important to understand, in detail, two-pion correlations measured in p+p and d+A collisions. In particular, one wishes to understand the femtoscopic correlations, in order to compare to similar measurements in heavy ion collisions.…
We analyze the mixing between $\Sigma^0$ and $\Lambda^0$ based on the baryon masses. We distinguish the contributions from QCD and QED in the baryon mass splittings. We find that the mixing angle between $\Sigma^0$ and $\Lambda^0$ is…
We reexamine radiative corrections to $\pi_{l2}$ and $K_{l2}$ decays. We perform a matching calculation, including vector and axial vector resonances as explicit degrees of freedom in the long distance part. By considering the dependence on…