9,297 research outputs found
The , , , , and as dynamically generated states from vector meson - vector meson interaction
We report on some recent developments in understanding the nature of the
low-lying mesonic resonances , , ,
, and . In particular we show that these five
resonances can be dynamically generated from vector meson--vector meson
interaction in a coupled-channel unitary approach, which utilizes the
phenomenologically very successful hidden-gauge Lagrangians to produce the
interaction kernel between two vector mesons, which is then unitarized by the
Bethe-Salpeter-equation method. The data on the strong decay branching ratios,
total decay widths, and radiative decay widths of these five states, and on
related decay processes can all be well described by such an approach.
We also make predictions, compare them with the results of earlier studies, and
highlight observables that if measured can be used to distinguish different
pictures of these resonances.Comment: 9 pages; Invited talk at workshop CHIRAL'10, Valencia (Spain), June
21-24, 201
Repercussion of the [] resonance and future developments
In this paper, we discuss the significance and prospect for the newly
discovered a0(1710)[a0(1817)] resonance state at BESIII experiment, in which
they reported the observation of a scalar meson of spin-parity with
isospin , branded as . This state may be the same particle as
the observed by the BaBar experiment earlier. As early as 2008, we
found that f0(1710) can be regarded as a molecular state based
on the chiral unitary theory, and there is a partner state with an
isospin . Our theoretical prediction based on this picture is in good
agreement with the latest BESIII data, which further supports the molecular
state picture of . If it is indeed the isospin partner
state of , this would rule out as a glueball candidate.
This paper briefly reviews the relevant theoretical studies and suggests new
experiments to further examine the nature of .Comment: typos corrected. 6 pages,4 figures, to be published as a
"Perspective" in Science Bulleti
Role of the (1535) in the and reactions
We study the and
reactions with a unitary chiral approach. We find that the unitary chiral
approach, which generates the dynamically, can describe the data
reasonably well, particularly the ratio of the integrated cross sections. This
study provides further support for the unitary chiral description of the
. We also discuss some subtle differences between the coupling
constants determined from the unitary chiral approach and those determined from
phenomenological studies.Comment: version to appear in PRC; certain features of the approach clarifie
Comments on the dispersion relation method to vector-vector interaction
We study in detail the method proposed recently to study the vector-vector
interaction using the method and dispersion relations, which concludes
that, while for , one finds bound states, in the case of , where the
interaction is also attractive and much stronger, no bound state is found. In
that work, approximations are done for and and a subtracted dispersion
relation for is used, with subtractions made up to a polynomial of second
degree in , matching the expression to at threshold. We
study this in detail for the interaction and to see the
convergence of the method we make an extra subtraction matching at
threshold up to . We show that the method cannot be used
to extrapolate the results down to 1270 MeV where the resonance
appears, due to the artificial singularity stemming from the "on shell"
factorization of the exchange potential. In addition, we explore the
same method but folding this interaction with the mass distribution of the
, and we show that the singularity disappears and the method allows one
to extrapolate to low energies, where both the and
expansions lead to a zero of , at
about the same energy where a realistic approach produces a bound state. Even
then, the method generates a large that we discuss is
unphysical.Comment: 8 pages, 10 figures, 1 tabl
Nature of the axial-vector mesons from their Nc behavior within the chiral unitary approach
By describing within the chiral unitary approach the s-wave interaction of
the vector meson nonet with the octet of pseudoscalar Goldstone Bosons, we find
that the main component of the axial vector mesons b_1(1235), h_1(1170),
h_1(1380), a_1(1260), f_1(1285) and the two states associated to the K_1(1270)
does not follow the QCD dependence on the number of colors for ordinary qqbar
mesons.Comment: 18 pages, 5 figures, to be published in EPJ
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