Abstract: We have evaluated the decay modes of the Upsilon(4s), Upsilon(3d), Upsilon(5s), Upsilon(6s) states into B (B) over bar, B (B) over bar* + c.c., B* (B) over bar*, B-s(B) over bar (s), B-s(B) over bar (s)* + c.c., B-s* (B) over bar (s)* using the P-3(0) model to hadronize the bb vector seed, fitting some parameters to the data. We observe that the Upsilon(4s) state has an abnormally large amount of mesonmeson components in the wave function, while the other states are largely b (b) over bar. We predict branching ratios for the different decay channels which can be contrasted with experiment for the case of the Upsilon(5s) state. While globally the agreement is fair, we call the attention to some disagreement that could be a warning for the existence of more elaborate components in the state.

Abstract: We develop a model to study the D-0 -> K-pi(+)eta weak decay, starting with the color favored external emission and Cabibbo favored mode at the quark level. A less favored internal emission decay mode is also studied as a source of small corrections. Some pairs of quarks are allowed to hadronize producing two pseudoscalar mesons, which posteriorly are allowed to interact to finally provide the K-pi(+)eta state. The chiral unitary approach is used to take into account the final state interaction of pairs of mesons, which has as a consequence the production of the kappa (K-0*(700)) and the a(0)(980) resonances, well visible in the invariant mass distributions. We also introduce the (K) over bar*(0)eta production in a phenomenological way and show that the s-wave pseudoscalar interaction together with this vector excitation mode are sufficient to provide a fair reproduction of the experimental data. The model provides the relative weight of the a(0)(980) to the kappa excitation, and their strength is clearly visible in the low energy part of the K pi spectrum.

Abstract: We study theoretically the structure of double pionic atoms, in which two negatively charged pions (pi(-)) are bound in the atomic orbits. The double pionic atom is considered to be an interesting system from the point of view of the multi-bosonic systems. In addition, it could be possible to deduce valuable information on the isospin I = 2 pi pi interaction and the pionnucleus strong interaction. In this paper, we take into account the pi pi strong and electromagnetic interactions, and evaluate the effects on the binding energies by perturbation theory for the double pionic atoms in heavy nuclei. We investigate several combinations of two pionic states and find that the order of magnitude of the energy shifts due to the pi pi interaction is around 10 keV for the strong interaction and around 100 keV for the electromagnetic interaction for the ground states.

Abstract: We study the semileptonic decay of Lambda(c) to nu l(+) and Lambda(1405), where the Lambda(1405) is seen in the invariant mass distribution of pi Sigma. We perform the hadronization of the quarks produced in the reaction in order to have a meson baryon pair in the final state and then let these hadron pairs undergo final state interaction from where the Lambda(1405) is dynamically generated. The reaction is particularly suited to study this resonance, because we show that it filters I = 0. It is also free of tree-level pi Sigma production, which leads to a clean signal of the resonance with no background. This same feature has as a consequence that one populates the state of the Lambda(1405) with higher mass around 1420 MeV, predicted by the chiral unitary approach. We make absolute predictions for the invariant mass distributions and find them within the measurable range in present facilities. The implementation of this reaction would allow us to gain insight into the existence of the predicted two Lambda(1405) states and their nature as molecular states.

Abstract: In this work we study the role of the f(0)(980) and a(0)(980) resonances in the low K+K- and K-0(K) over bar (0) invariant-mass region of the B- -> pi-K+K- and B- -> pi K--(0)(K) over bar (0) reactions. The amplitudes are calculated by using the chiral unitary SU(3) formalism, in which these two resonances are dynamically generated from the unitary pseudoscalar-pseudoscalar coupled-channel approach. The amplitudes are then used as input in the evaluation of the mass distributions with respect to the K+K- and K-0(K) over bar (0) invariant masses, where the contributions coming from the I = 0 and I = 1 components are explicitly assessed. Furthermore, the contribution of the K*(892)K-0(-) production and its influence on the pi K--(+) and K+K- systems are also evaluated, showing that there is no significant strength for small K+K- invariant mass. Finally, the final distributions of M-inv(2) ((KK -/+)-K-+/-) for the B--/+ -> pi(KK -/+)-K--/+-K-+/- reactions are estimated and compared with the LHCb data. Our results indicate that the I = 0 component tied to the f(0)(980) excitation generates the dominant contribution in the range of low K+K- invariant mass.