We study the possible contribution of the nucleon’s virtual meson cloud to the sea quark distribution as observed in deep inelastic lepton scattering. We adjust the meson-nucleon cut-offs to the large-x tails of the antiquark distributions, find qualitatively different behavior in the flavor singlet and non-singlet channels and study the scale dependence of our results. We demonstrate that, wit...

The very recently observed D∗ sJ (2317) meson is described as a quasi-bound scalar cs̄ state in a unitarized meson model, owing its existence to the strong P0 OZI-allowed coupling to the nearby S-wave DK threshold. By the same mechanism, a scalar D∗ 0(2100– 2300) resonance is predicted above the Dπ threshold. These scalars are the charmed cousins of the light scalar nonet f0(600), f0(980), K ∗ 0...

The very recently observed D∗ sJ (2317) meson is described as a quasi-bound scalar cs̄ state in a unitarized meson model, owing its existence to the strong P0 OZI-allowed coupling to the nearby S-wave DK threshold. By the same mechanism, a scalar D∗ 0(2100– 2300) resonance is predicted above the Dπ threshold. These scalars are the charmed cousins of the light scalar nonet f0(600), f0(980), K ∗ 0...

The analysis of the poles of the ππ scattering amplitude is shown to favour a dynamical origin of the sigma meson: it is created by a strongly attractive ππ interaction in the J = 0I = 0 channel. In the limit Nc → ∞, the σ meson disappears, contrary to the case of conventional qq̄ states. Implications for the search of the scalar qq̄ and glueball states are discussed.

Strong final-state interactions create a pronounced cusp in η → ηππ decays. We adapt and generalize the non-relativistic effective field theory framework developed for the extraction of ππ scattering lengths from K → 3π decays to this case. The cusp effect is predicted to have an effect of more than 8% on the decay spectrum below the ππ threshold. PACS. 11.30.Rd Chiral symmetries – 13.25.Jx Dec...

Decays of η and η ′ within a chiral unitary approach Various decays of η and η ′ 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 sand p-wave interaction kernels for meson-meson scattering from the chiral effective Lagrangian and iterating them in a Bethe-Sa...

Spin effects in B c → X c¯ c π(ρ) decays. Abstract The two-particle hadronic decays of B c meson into S-wave and P-wave charmonium states X c¯ c are considered in the framework of hard gluon exchange model. It is shown that decay width of B c meson into S-wave charmonium states doubly exceeds one for P-wave states. In compare with the previous estimations we predict the enhancement by 8 % the b...

We review coherent scattering of neutrinos on nuclei by coupling the weak currents to vector and axial-vector meson states. The couplings are obtained from known reactions, like τ –lepton and vector meson decays. We compute and present the cross sections as functions of energy and momentum transfer for various kinematic regions, including those which are relevant to oscillation experiments. The...

By a reformulation of the loop expansion in the Resonance-Spectrum-Expansion amplitude for meson-meson scattering, in terms of s-channel exchange of families of propagator modes, we obtain a formalism which allows for a wider range of applications. The connection with the unitarized amplitudes employed in some chiral theories is discussed. We also define an alternative for the Regge spectra and...

We review coherent scattering of neutrinos on nuclei by coupling the weak currents to vector and axial-vector meson states. The couplings are obtained from known reactions, like τ–lepton and vector meson decays. We compute and present the cross sections as functions of energy and momentum transfer for various kinematic regions, including those which are relevant to oscillation experiments. The ...