3,673 research outputs found
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 , , ,
and a not yet discovered resonance are basically molecules made of an
increasing number of and one mesons. The idea relies on
the fact that the vector-vector interaction in s-wave with spins aligned is
very strong both for and . We extend a recent work, where
several resonances showed up as multi- molecules, to the strange
sector including the 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: ,
, , , and two poles to the
resonance. We evaluate the couplings of the resonances to the
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 decay and in the medium through nuclear photoproduction
In order to assess the relevance of chiral dynamics in the scalar sector we
address two recent problems: radiative decay of the , for which there are
quite recent data from Frascati, and the modification of the
properties in the nuclear medium seen through the 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 , and decay into and 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 , 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 resonances
The axial vector meson 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 at 63 GeV, which
established the existence of both and , 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 resonances
Unitary chiral dynamics in decays into and the role of the scalar mesons
We make a theoretical study of the \J decays into ,
, and 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
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