On the nature of the K*2(1430), K*3(1780), K*4(2045), K*5(2380) and K*6 as K*--multi-rho states

We show that the $K^*_2(1430)$, $K^*_3(1780)$, $K^*_4(2045)$, $K^*_5(2380)$ and a not yet discovered $K_6^*$ resonance are basically molecules made of an increasing number of $\rho(770)$ and one $K^*(892)$ mesons. The idea relies on the fact that the vector-vector interaction in s-wave with spins aligned is very strong both for $\rho\rho$ and $K^*\rho$. We extend a recent work, where several resonances showed up as multi-$\rho(770)$ molecules, to the strange sector including the $K^*(892)$ into the system. The resonant structures show up in the multi-body scattering amplitudes, which are evaluated in terms of the unitary two-body vector-vector scattering amplitudes by using the fixed center approximation to the Faddeev equations

Low lying axial-vector mesons as dynamically generated resonances

We make a theoretical study of the s-wave interaction of the nonet of vector mesons with the octet of pseudoscalar mesons starting from a chiral invariant Lagrangian and implementing unitarity in coupled channels. By looking for poles in the unphysical Riemann sheets of the unitarized scattering amplitudes, we get two octets and one singlet of axial-vector dynamically generated resonances. The poles found can be associated to most of the low lying axial-vector resonances quoted in the Particle Data Book: $b_1(1235)$, $h_1(1170)$, $h_1(1380)$, $a_1(1260)$, $f_1(1285)$ and two poles to the $K_1(1270)$ resonance. We evaluate the couplings of the resonances to the $VP$ states and the partial decay widths in order to reinforce the arguments in the discussion.Comment: 31 pages, 12 figures, Accepted for publication in Phys.Rev.

Chiral Dynamics of scalar mesons: radiative ϕ\phi decay and σ\sigma in the medium through π0π0\pi^0 \pi^0 nuclear photoproduction

In order to assess the relevance of chiral dynamics in the scalar sector we address two recent problems: radiative decay of the $\phi$, for which there are quite recent data from Frascati, and the modification of the $\sigma$ properties in the nuclear medium seen through the $\pi^0 \pi^0$ photoproduction in nuclei.Comment: Talk given at the High Energy Physics Workshop "Scalar Mesons: an Interesting Puzzle for QCD", Utica, New York, May 200

Radiative vector meson decay

We study the radiative $\rho$, $\omega$ and $\phi$ decay into $\pi^0 \pi^0 \gamma$ and $\pi^0 \eta \gamma$ taking into account mechanisms in which there are two sequential vector-vector-pseudoscalar or axial-vector--vector--pseudoscalar steps followed by the coupling of a vector meson to the photon, considering the final state interaction of the two mesons. Other mechanisms in which two kaons are produced through the same sequential mechanisms or from vector meson decay into two kaons which undergo final state interaction leading to the final pair of pions or $\pi^0 \eta$, are also considered. The results of the parameter free theory, together with the theoretical uncertainties, are compared with the latest experimental results at Frascati and Novosibirsk.Comment: Prepared for the 10th International Symposium on Meson-Nucleon Physics and the Structure of the Nucleo

Clues for the existence of two K1(1270)K_1(1270) resonances

The axial vector meson $K_1(1270)$ was studied within the chiral unitary approach, where it was shown that it has a two-pole structure. We reanalyze the high-statistics WA3 experiment $K^- p\to K^-\pi^+\pi^- p$ at 63 GeV, which established the existence of both $K_1(1270)$ and $K_1(1400)$, and we show that it clearly favors our two-pole interpretation. We also reanalyze the traditional K-matrix interpretation of the WA3 data and find that the good fit of the data obtained there comes from large cancellations of terms of unclear physical interpretation.Comment: published version in PRD; typos corrected; title changed to "Clues for the existence of two $K_1(1270)$ resonances

Unitary chiral dynamics in J/ΨJ/\Psi decays into VPPVPP and the role of the scalar mesons

We make a theoretical study of the \J decays into $\omega\pi\pi$, $\phi\pi\pi$, $\omega K \bar{K}$ and $\phi K\bar{K}$ using the techniques of the chiral unitary approach stressing the important role of the scalar resonances dynamically generated through the final state interaction of the two pseudoscalar mesons. We also discuss the importance of new mechanisms with intermediate exchange of vector and axial-vector mesons and the role played by the OZI rule in the \J\phi\pi\pi vertex, quantifying its effects. The results nicely reproduce the experimental data for the invariant mass distributions in all the channels considered.Comment: Prepared for the 10th International Symposium on Meson-Nucleon Physics and the Structure of the Nucleo

Restos de grulla fósil en el avenc de na Corna, Artà

[spa] La abundancia de depósitos osíferos en las cavidades de Mallorca con restos fósiles de mamíferos endémicos como Myotragus, Hypnomys y Nesiotites, y la escasez de otras especies, hacen que el "Avenc de Na Corna" tenga un interés especial al ser hallados en él, restos de una grulla fósil, que hasta la fecha es la primera cita de esta ave en las islas y la península